Update version to 2026.8.200

This change adds cached and incremental analysis for the LSP
server to improve responsiveness. The client now debounces
diagnostic updates to avoid excessive recomputation. The
server introduces per-document line caches and various
caches for completions, inlay hints, and metadata to
support faster, incremental updates.

- Debounce diagnostics on text changes to reduce noise.
- Add caches for completions, inlay hints, and metadata.
- Introduce incremental analysis with per-document line caches.

.vscode/launch.json

@@ -10,13 +10,21 @@
             "type": "extensionHost",
             "request": "launch",
             "runtimeExecutable": "${execPath}",
-            "args": ["--extensionDevelopmentPath=${workspaceFolder}"],
+            "args": [
-            "outFiles": ["${workspaceFolder}/client/**/*.js"],
+                "--extensionDevelopmentPath=${env:TEMP}/nx-post-support-vscode-debug",
+                "${env:TEMP}/nx-post-support-vscode-debug",
+                "${env:TEMP}/nx-post-support-vscode-debug/test/test.tcl"
+            ],
+            "cwd": "${env:TEMP}/nx-post-support-vscode-debug",
+            "outFiles": ["${env:TEMP}/nx-post-support-vscode-debug/dist/**/*.js"],
+            "sourceMaps": true,
+            "resolveSourceMapLocations": [
+                "${env:TEMP}/nx-post-support-vscode-debug/dist/**/*.js",
+                "!**/node_modules/**"
+            ],
+            "skipFiles": ["<node_internals>/**"],
             "autoAttachChildProcesses": true,
-            "preLaunchTask": {
+            "preLaunchTask": "NX Post Support: Compile Debug"
-                "type": "npm",
-                "script": "watch"
-            }
         },
         {
             "name": "Python Attach",
@@ -34,10 +42,24 @@
             "name": "Debug Extension (hidden)",
             "type": "extensionHost",
             "request": "launch",
-            "args": ["--extensionDevelopmentPath=${workspaceFolder}"],
+            "runtimeExecutable": "${execPath}",
-            "outFiles": ["${workspaceFolder}/client/**/*.js"],
+            "args": [
+                "--extensionDevelopmentPath=${env:TEMP}/nx-post-support-vscode-debug",
+                "${env:TEMP}/nx-post-support-vscode-debug",
+                "${env:TEMP}/nx-post-support-vscode-debug/test/test.tcl"
+            ],
+            "cwd": "${env:TEMP}/nx-post-support-vscode-debug",
+            "outFiles": ["${env:TEMP}/nx-post-support-vscode-debug/dist/**/*.js"],
+            "sourceMaps": true,
+            "resolveSourceMapLocations": [
+                "${env:TEMP}/nx-post-support-vscode-debug/dist/**/*.js",
+                "!**/node_modules/**"
+            ],
+            "skipFiles": ["<node_internals>/**"],
             "env": {
-                "USE_DEBUGPY": "True"
+                "USE_DEBUGPY": "True",
+                "NXPS_DEBUG_HOST": "127.0.0.1",
+                "NXPS_DEBUG_PORT": "5678"
             },
             "presentation": {
                 "hidden": true,
@@ -49,8 +71,9 @@
             "name": "Python debug server (hidden)",
             "type": "debugpy",
             "request": "attach",
-            "listen": { "host": "localhost", "port": 5678 },
+            "listen": { "host": "127.0.0.1", "port": 5678 },
-            "justMyCode": true,
+            "justMyCode": false,
+            "logToFile": true,
             "presentation": {
                 "hidden": true,
                 "group": "",
@@ -63,7 +86,7 @@
             "name": "Debug Extension and Python",
             "configurations": ["Python debug server (hidden)", "Debug Extension (hidden)"],
             "stopAll": true,
-            "preLaunchTask": "npm: watch",
+            "preLaunchTask": "NX Post Support: Compile Debug",
             "presentation": {
                 "hidden": false,
                 "group": "",

.vscode/prepare-debug.ps1

@@ -0,0 +1,57 @@
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$WorkspaceRoot,
+
+    [Parameter(Mandatory = $true)]
+    [string]$DebugRoot
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+function ConvertFrom-ExtendedWindowsPath {
+    param([string]$Path)
+
+    if ($Path.StartsWith("\\?\UNC\", [System.StringComparison]::OrdinalIgnoreCase)) {
+        return "\\" + $Path.Substring(8)
+    }
+    if ($Path.StartsWith("\\?\", [System.StringComparison]::OrdinalIgnoreCase)) {
+        return $Path.Substring(4)
+    }
+    return $Path
+}
+
+$workspacePath = ConvertFrom-ExtendedWindowsPath $WorkspaceRoot
+$workspaceItem = Get-Item -LiteralPath $workspacePath
+if (-not $workspaceItem.PSIsContainer) {
+    throw "Workspace root is not a directory: $workspacePath"
+}
+$workspacePath = $workspaceItem.FullName
+
+$debugPath = ConvertFrom-ExtendedWindowsPath $DebugRoot
+$tempPath = [System.IO.Path]::GetFullPath([System.IO.Path]::GetTempPath()).TrimEnd("\")
+$debugParent = [System.IO.Path]::GetFullPath((Split-Path -Parent $debugPath)).TrimEnd("\")
+if (-not $debugParent.Equals($tempPath, [System.StringComparison]::OrdinalIgnoreCase)) {
+    throw "Debug alias must be located directly below the user temp directory: $debugPath"
+}
+
+if (Test-Path -LiteralPath $debugPath) {
+    $debugItem = Get-Item -LiteralPath $debugPath -Force
+    if ($debugItem.LinkType -ne "Junction") {
+        throw "Debug alias exists but is not a junction: $debugPath"
+    }
+
+    $currentTarget = (Get-Item -LiteralPath $debugItem.Target).FullName
+    if (-not $currentTarget.Equals($workspacePath, [System.StringComparison]::OrdinalIgnoreCase)) {
+        # Removing a junction removes only the link, never the target directory.
+        Remove-Item -LiteralPath $debugPath -Force
+    }
+}
+
+if (-not (Test-Path -LiteralPath $debugPath)) {
+    New-Item -ItemType Junction -Path $debugPath -Target $workspacePath | Out-Null
+}
+
+Write-Output "Debug extension path: $debugPath -> $workspacePath"
+& npm.cmd --prefix $workspacePath run compile:debug
+exit $LASTEXITCODE

.vscode/tasks.json

@@ -0,0 +1,26 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "NX Post Support: Compile Debug",
+            "type": "process",
+            "command": "powershell.exe",
+            "args": [
+                "-NoLogo",
+                "-NoProfile",
+                "-ExecutionPolicy",
+                "Bypass",
+                "-Command",
+                "& { param([string]$WorkspaceRoot, [string]$DebugRoot); $scriptRoot = $WorkspaceRoot; if ($scriptRoot.StartsWith('\\\\?\\')) { $scriptRoot = $scriptRoot.Substring(4) }; & (Join-Path $scriptRoot '.vscode\\prepare-debug.ps1') -WorkspaceRoot $WorkspaceRoot -DebugRoot $DebugRoot; exit $LASTEXITCODE }",
+                "${workspaceFolder}",
+                "${env:TEMP}\\nx-post-support-vscode-debug"
+            ],
+            "problemMatcher": [],
+            "presentation": {
+                "reveal": "always",
+                "panel": "dedicated",
+                "clear": true
+            }
+        }
+    ]
+}

CHANGELOG.md

@@ -1,3 +1,14 @@
+## Unreleased
+
+- Prevent truncated TCL inlay hints and add configurable parameter hint modes
+- Add inlay hints for built-in NX procedures, variadic arguments, and visible ranges
+- Add inlay hint documentation and navigation to custom procedure definitions
+- Add signature help for custom TCL procedures and built-in NX/MOM procedures
+- Clean stale TCL indexes on close, delete, and rename operations
+- Make background parsing and index updates thread-safe
+- Improve TCL response times with debounced edits and cached semantic, inlay, hover, completion, and variable indexes
+- Debounce CDL/DEF diagnostics and remove per-line diagnostic logging
+
 ## [0.0.1]
 
 - Initial release

README.md

@@ -9,6 +9,7 @@ A comprehensive VS Code extension providing language support for NX CAM postproc
 - **Multi-language Support** - Supports NX CDL, TCL, and DEF file formats
 - **Intelligent Code Analysis** - Linting and error detection for postprocessor code
 - **Auto-completion** - Context-aware code completion for faster development
+- **Signature Help** - Shows parameters and documentation for custom and NX procedures
 
 ## Supported File Types
 
@@ -19,7 +20,7 @@ A comprehensive VS Code extension providing language support for NX CAM postproc
 ## Installation
 
 1. Install from the VS Code Marketplace
-2. Install Python 3.8 or higher
+2. Install Python 3.11 or higher
 3. Open any `.cdl`, `.tcl`, or `.def` file
 4. The extension will automatically activate and provide language support
 
@@ -30,6 +31,12 @@ The extension can be configured through VS Code settings:
 - `nx-post-support.interpreter` - Specify custom Python interpreter path for the language server
 - `nx-post-support.formatter` - Enable/disable the TCL formatter (default: false)
 - `nx-post-support.inlayHint` - Enable/disable inlay Hints (default: true)
+- `nx-post-support.inlayHints.parameterNames` - Show parameter names for `all`, only `literals`, or `none` (default: `all`)
+- `nx-post-support.inlayHints.suppressWhenArgumentMatchesName` - Hide redundant hints such as `value:` before `$value` (default: true)
+
+TCL files default to unlimited inlay hint length so that VS Code does not
+truncate later parameter names on a line. An explicit user setting for
+`editor.inlayHints.maximumLength` still takes precedence.
 
 ## Usage
 
@@ -40,6 +47,30 @@ Simply open any supported file type and enjoy:
 - Code completion
 - Code formatting (Format Document command)
 - Hover information
+- Signature help while entering procedure arguments
+
+## Development and debugging
+
+Install the root and client dependencies before the first debug session:
+
+```powershell
+npm install
+npm install --prefix client
+```
+
+Use one of the checked-in VS Code launch configurations:
+
+- **Run Extension** debugs the TypeScript extension host.
+- **Debug Extension and Python** debugs both the TypeScript extension and the
+  Python language server. This is the recommended configuration for LSP work.
+- **Python Attach** attaches manually to an already running Python process.
+
+The launch configuration creates a fresh non-minified bundle with embedded
+source maps and opens `test/test.tcl` so the extension activates immediately.
+For combined debugging, the Python adapter listens on `127.0.0.1:5678`; the
+language server waits for that adapter before initialization. The NX
+Postprocessor Support output channel reports `Python debug mode: enabled` and
+shows `_debug_server.py` in the server command when the debug path is active.
 
 ## Contributing
 

client/package-lock.json

@@ -14,6 +14,7 @@
         "vscode-languageclient": "^9.0.1"
       },
       "devDependencies": {
+        "@types/fs-extra": "^11.0.4",
         "@types/node": "^22.10.5",
         "@types/vscode": "^1.96.0"
       },
@@ -21,6 +22,27 @@
         "vscode": "^1.96.0"
       }
     },
+    "node_modules/@types/fs-extra": {
+      "version": "11.0.4",
+      "resolved": "https://registry.npmjs.org/@types/fs-extra/-/fs-extra-11.0.4.tgz",
+      "integrity": "sha512-yTbItCNreRooED33qjunPthRcSjERP1r4MqCZc7wv0u2sUkzTFp45tgUfS5+r7FrZPdmCCNflLhVSP/o+SemsQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/jsonfile": "*",
+        "@types/node": "*"
+      }
+    },
+    "node_modules/@types/jsonfile": {
+      "version": "6.1.4",
+      "resolved": "https://registry.npmjs.org/@types/jsonfile/-/jsonfile-6.1.4.tgz",
+      "integrity": "sha512-D5qGUYwjvnNNextdU59/+fI+spnwtTFmyQP0h+PfIOSkNfpU6AOICUOkm4i0OnSk+NyjdPJrxCDro0sJsWlRpQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/node": {
       "version": "22.10.5",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-22.10.5.tgz",

client/package.json

@@ -12,6 +12,7 @@
     "vscode-languageclient": "^9.0.1"
   },
   "devDependencies": {
+    "@types/fs-extra": "^11.0.4",
     "@types/node": "^22.10.5",
     "@types/vscode": "^1.96.0"
   }

client/src/common/cdlEventHandler.ts

@@ -0,0 +1,116 @@
+export interface CdlEventHandler {
+    eventName: string
+    parameterNames: string[]
+}
+
+function structuralCode(line: string): string {
+    let result = ""
+    let inString = false
+    let escaped = false
+
+    for (const character of line) {
+        if (escaped) {
+            escaped = false
+            result += inString ? " " : character
+            continue
+        }
+        if (character === "\\") {
+            escaped = true
+            result += inString ? " " : character
+            continue
+        }
+        if (character === '"') {
+            inString = !inString
+            result += " "
+            continue
+        }
+        if (character === "#" && !inString) {
+            break
+        }
+        result += inString ? " " : character
+    }
+
+    return result
+}
+
+function braceDelta(line: string): number {
+    let delta = 0
+    for (const character of structuralCode(line)) {
+        if (character === "{") {
+            delta += 1
+        } else if (character === "}") {
+            delta -= 1
+        }
+    }
+    return delta
+}
+
+export function cdlEventHandlerAtLine(
+    source: string,
+    declarationLine: number
+): CdlEventHandler | undefined {
+    const lines = source.split(/\r?\n/)
+    const declaration = lines[declarationLine]
+    if (declaration === undefined) {
+        return undefined
+    }
+
+    const eventMatch = /^\s*EVENT\s+([^\s{]+)/.exec(structuralCode(declaration))
+    if (!eventMatch) {
+        return undefined
+    }
+
+    const parameterNames: string[] = []
+    let eventOpened = false
+    let depth = 0
+
+    for (let lineNumber = declarationLine; lineNumber < lines.length; lineNumber++) {
+        const line = lines[lineNumber]
+        const code = structuralCode(line)
+
+        if (eventOpened && depth === 1) {
+            const parameterMatch = /^\s*PARAM\s+([^\s{]+)/.exec(code)
+            if (parameterMatch) {
+                parameterNames.push(parameterMatch[1])
+            }
+        }
+
+        const delta = braceDelta(line)
+        if (!eventOpened && delta > 0) {
+            eventOpened = true
+        }
+        if (eventOpened) {
+            depth += delta
+            if (depth <= 0) {
+                break
+            }
+        }
+    }
+
+    return {
+        eventName: eventMatch[1],
+        parameterNames
+    }
+}
+
+function momEventName(eventName: string): string {
+    return `MOM_${eventName.replace(/^MOM_/i, "")}`
+}
+
+function momVariableName(parameterName: string): string {
+    return `mom_${parameterName.replace(/^mom_/i, "")}`
+}
+
+export function createCdlEventHandlerSnippet(handler: CdlEventHandler): string {
+    const globals = [
+        ...new Set(handler.parameterNames.map((parameter) => momVariableName(parameter)))
+    ]
+    const lines = [`proc ${momEventName(handler.eventName)} { } {`]
+
+    if (globals.length > 0) {
+        lines.push(...globals.map((variable) => `    global ${variable}`), "")
+    }
+    lines.push("    #Put your UDE Handler Tcl here", "", "}")
+
+    return lines.join("\n")
+}

client/src/common/handlers.ts

@@ -1,4 +1,10 @@
 import * as vscode from "vscode"
+import {
+    cdlEventHandlerAtLine,
+    createCdlEventHandlerSnippet
+} from "./cdlEventHandler"
+
+const MACHINE_HEADER_REGEX = /^MACHINE\s+\S+/
 
 export function formatCdlFile(content: string): string {
     let indentLevel = 0
@@ -37,15 +43,19 @@ export function formatDefFile(content: string): string {
 }
 
 export function isFirstLineMachine(content: string): boolean {
-    const lines = content.split("\n").map((line) => line.trim())
+    let lineStart = 0
-    for (const line of lines) {
+    while (lineStart <= content.length) {
-        console.log(line)
+        const newline = content.indexOf("\n", lineStart)
+        const lineEnd = newline === -1 ? content.length : newline
+        const line = content.slice(lineStart, lineEnd).trim()
         if (line === "" || line.startsWith("#")) {
-            console.log("skipping line")
+            if (newline === -1) {
+                return false
+            }
+            lineStart = newline + 1
             continue
         }
-        const machineRegex = /^MACHINE\s+\S+/
+        return MACHINE_HEADER_REGEX.test(line)
-        return machineRegex.test(line)
     }
     return false
 }
@@ -53,10 +63,11 @@ export function isFirstLineMachine(content: string): boolean {
 export function diagnosticHandler(document: vscode.TextDocument) {
     const diagnostics: vscode.Diagnostic[] = []
     if (document.languageId === "cdl" || document.languageId === "def") {
-        if (!isFirstLineMachine(document.getText())) {
+        const text = document.getText()
+        if (!isFirstLineMachine(text)) {
             const range = new vscode.Range(
                 document.positionAt(0),
-                document.positionAt(document.getText().length)
+                document.positionAt(text.length)
             )
             const diagnostic = new vscode.Diagnostic(
                 range,
@@ -110,33 +121,132 @@ export function completionHandlerCdl(document: vscode.TextDocument, position: vs
 }
 
 export function hoverCdlHandler(document: vscode.TextDocument, position: vscode.Position) {
-    const wordRange = document.getWordRangeAtPosition(position)
+    const line = document.lineAt(position.line).text
-    const word = document.getText(wordRange)
+    const eventMatch = /^\s*EVENT\s+([^\s{]+)/.exec(line)
-    const text = document.getText()
+    if (eventMatch) {
-    const lines = text.split("\n")
+        const eventStart = line.indexOf(eventMatch[1], eventMatch.index)
-
+        const declarationEnd = eventStart + eventMatch[1].length
-    let hoverText: string | undefined
+        if (position.character <= declarationEnd) {
-
+            const handler = cdlEventHandlerAtLine(document.getText(), position.line)
-    for (const line of lines) {
+            if (handler) {
-        const words = line.split(/\s+/)
+                const markdown = new vscode.MarkdownString()
-        const wordIndex = words.indexOf(word)
+                markdown.appendCodeblock(createCdlEventHandlerSnippet(handler), "tcl")
-
+                return new vscode.Hover(
-        if (wordIndex > 0) {
+                    markdown,
-            if (words[wordIndex - 1] === "EVENT") {
+                    new vscode.Range(position.line, eventMatch.index, position.line, declarationEnd)
-                hoverText = `MOM_${word}`
+                )
-            } else if (words[wordIndex - 1] === "PARAM") {
-                hoverText = `mom_${word}`
             }
-            break
         }
     }
 
-    if (hoverText) {
+    const parameterMatch = /^\s*PARAM\s+([^\s{]+)/.exec(line)
-        return new vscode.Hover(hoverText)
+    if (parameterMatch) {
+        const parameterStart = line.indexOf(parameterMatch[1], parameterMatch.index)
+        const parameterEnd = parameterStart + parameterMatch[1].length
+        if (position.character >= parameterStart && position.character <= parameterEnd) {
+            return new vscode.Hover(`mom_${parameterMatch[1].replace(/^mom_/i, "")}`)
         }
+    }
+
     return undefined
 }
 
+function escapeRegExp(value: string): string {
+    return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")
+}
+
+export function cdlEventAtPosition(
+    document: vscode.TextDocument,
+    position: vscode.Position
+): string | undefined {
+    const line = document.lineAt(position.line).text
+    const match = /^\s*EVENT\s+([^\s{]+)/.exec(line)
+    if (!match) {
+        return undefined
+    }
+
+    const declarationStart = match.index
+    const eventEnd = line.indexOf(match[1], match.index) + match[1].length
+    if (position.character < declarationStart || position.character > eventEnd) {
+        return undefined
+    }
+    return match[1]
+}
+
+export async function definitionCdlEventHandler(
+    document: vscode.TextDocument,
+    position: vscode.Position,
+    token: vscode.CancellationToken
+): Promise<vscode.Location[] | undefined> {
+    const eventName = cdlEventAtPosition(document, position)
+    if (!eventName) {
+        return undefined
+    }
+
+    const handlerName = `MOM_${eventName}`
+    try {
+        const symbols = await vscode.commands.executeCommand<vscode.SymbolInformation[]>(
+            "vscode.executeWorkspaceSymbolProvider",
+            handlerName
+        )
+        const indexedLocations = (symbols || [])
+            .filter(
+                (symbol) =>
+                    symbol.kind === vscode.SymbolKind.Function &&
+                    (symbol.name === handlerName ||
+                        symbol.name.endsWith(`::${handlerName}`))
+            )
+            .map((symbol) => symbol.location)
+        if (indexedLocations.length > 0) {
+            return indexedLocations
+        }
+    } catch {
+        // The Tcl language server may still be starting; use the file fallback below.
+    }
+
+    const declaration = new RegExp(
+        `^\\s*proc\\s+(?:::)?${escapeRegExp(handlerName)}(?=\\s|\\{)`
+    )
+    const tclFiles = await vscode.workspace.findFiles(
+        "**/*.tcl",
+        "**/{.git,.nox,.venv,dist,node_modules,out}/**"
+    )
+    const locations: vscode.Location[] = []
+
+    for (const uri of tclFiles) {
+        if (token.isCancellationRequested) {
+            return undefined
+        }
+        let tclDocument: vscode.TextDocument
+        try {
+            tclDocument = await vscode.workspace.openTextDocument(uri)
+        } catch {
+            continue
+        }
+        for (let lineNumber = 0; lineNumber < tclDocument.lineCount; lineNumber++) {
+            const line = tclDocument.lineAt(lineNumber).text
+            const match = declaration.exec(line)
+            if (!match) {
+                continue
+            }
+            const start = line.indexOf(handlerName, match.index)
+            locations.push(
+                new vscode.Location(
+                    uri,
+                    new vscode.Range(
+                        lineNumber,
+                        start,
+                        lineNumber,
+                        start + handlerName.length
+                    )
+                )
+            )
+        }
+    }
+
+    return locations.length > 0 ? locations : undefined
+}
+
 export function tclDocumentSymbolProvider(document: vscode.TextDocument): vscode.DocumentSymbol[] {
     const symbols: vscode.DocumentSymbol[] = []
     const lines = document.getText().split("\n")

client/src/common/server.ts

@@ -2,7 +2,7 @@
 // Licensed under the MIT License.
 
 import * as fsapi from "fs-extra"
-import { Disposable, env, LogOutputChannel } from "vscode"
+import { Disposable, env, LogOutputChannel, workspace } from "vscode"
 import { State } from "vscode-languageclient"
 import {
     LanguageClient,
@@ -24,6 +24,13 @@ import { isVirtualWorkspace } from "./vscodeapi"
 
 export type IInitOptions = { settings: ISettings[]; globalSettings: ISettings }
 
+let _disposables: Disposable[] = []
+
+export function disposeServerResources(): void {
+    _disposables.forEach((disposable) => disposable.dispose())
+    _disposables = []
+}
+
 async function createServer(
     settings: ISettings,
     serverId: string,
@@ -32,13 +39,26 @@ async function createServer(
     initializationOptions: IInitOptions
 ): Promise<LanguageClient> {
     const command = settings.interpreter[0]
+    if (!command) {
+        throw new Error("No Python interpreter is configured for the language server.")
+    }
     const cwd = settings.cwd
 
     // Set debugger path needed for debugging python code.
     const newEnv = { ...process.env }
-    const debuggerPath = await getDebuggerPath()
     const isDebugScript = await fsapi.pathExists(DEBUG_SERVER_SCRIPT_PATH)
-    if (newEnv.USE_DEBUGPY && debuggerPath) {
+    const debugRequested = newEnv.USE_DEBUGPY?.toLowerCase() === "true"
+    if (debugRequested && !isDebugScript) {
+        throw new Error(`Python debug bootstrap not found: ${DEBUG_SERVER_SCRIPT_PATH}`)
+    }
+
+    const debuggerPath = debugRequested ? await getDebuggerPath() : undefined
+    if (debugRequested && !debuggerPath) {
+        throw new Error(
+            "Python debugging was requested, but the Python Debugger extension did not provide debugpy."
+        )
+    }
+    if (debugRequested && debuggerPath) {
         newEnv.DEBUGPY_PATH = debuggerPath
     } else {
         newEnv.USE_DEBUGPY = "False"
@@ -50,10 +70,13 @@ async function createServer(
     // Set notification type
     newEnv.LS_SHOW_NOTIFICATION = settings.showNotifications
 
-    const args =
+    const serverScript = debugRequested ? DEBUG_SERVER_SCRIPT_PATH : SERVER_SCRIPT_PATH
-        newEnv.USE_DEBUGPY === "False" || !isDebugScript
+    const interpreterArgs = settings.interpreter.slice(1)
-            ? settings.interpreter.slice(1).concat([SERVER_SCRIPT_PATH])
+    if (debugRequested && !interpreterArgs.includes("-Xfrozen_modules=off")) {
-            : settings.interpreter.slice(1).concat([DEBUG_SERVER_SCRIPT_PATH])
+        interpreterArgs.push("-Xfrozen_modules=off")
+    }
+    const args = interpreterArgs.concat([serverScript])
+    traceInfo(`Python debug mode: ${debugRequested ? "enabled" : "disabled"}`)
     traceInfo(`Server run command: ${[command, ...args].join(" ")}`)
 
     const serverOptions: ServerOptions = {
@@ -63,6 +86,7 @@ async function createServer(
     }
 
     // Options to control the language client
+    const tclFileWatcher = workspace.createFileSystemWatcher("**/*.tcl")
     const clientOptions: LanguageClientOptions = {
         // Register the server for python documents
         documentSelector: isVirtualWorkspace()
@@ -76,13 +100,16 @@ async function createServer(
         outputChannel: outputChannel,
         traceOutputChannel: outputChannel,
         revealOutputChannelOn: RevealOutputChannelOn.Never,
+        synchronize: {
+            fileEvents: tclFileWatcher
+        },
         initializationOptions
     }
 
+    _disposables.push(tclFileWatcher)
     return new LanguageClient(serverId, serverName, serverOptions, clientOptions)
 }
 
-let _disposables: Disposable[] = []
 export async function restartServer(
     serverId: string,
     serverName: string,
@@ -92,16 +119,22 @@ export async function restartServer(
     if (lsClient) {
         traceInfo(`Server: Stop requested`)
         await lsClient.stop()
-        _disposables.forEach((d) => d.dispose())
+        disposeServerResources()
-        _disposables = []
     }
     const projectRoot = await getProjectRoot()
     const workspaceSetting = await getWorkspaceSettings(serverId, projectRoot, true)
 
-    const newLSClient = await createServer(workspaceSetting, serverId, serverName, outputChannel, {
+    try {
+        const newLSClient = await createServer(
+            workspaceSetting,
+            serverId,
+            serverName,
+            outputChannel,
+            {
                 settings: await getExtensionSettings(serverId, true),
                 globalSettings: await getGlobalSettings(serverId, false)
-    })
+            }
+        )
         traceInfo(`Server: Start requested.`)
         _disposables.push(
             newLSClient.onDidChangeState((e) => {
@@ -118,14 +151,13 @@ export async function restartServer(
                 }
             })
         )
-    try {
         await newLSClient.start()
-    } catch (ex) {
-        traceError(`Server: Start failed: ${ex}`)
-        return undefined
-    }
-
         const level = getLSClientTraceLevel(outputChannel.logLevel, env.logLevel)
         await newLSClient.setTrace(level)
         return newLSClient
+    } catch (ex) {
+        traceError(`Server: Start failed: ${ex}`)
+        disposeServerResources()
+        return undefined
+    }
 }

client/src/common/settings.ts

@@ -18,6 +18,12 @@ export interface ISettings {
     interpreter: string[]
     importStrategy: string
     showNotifications: string
+    formatter: boolean
+    inlayHint: boolean
+    inlayHints: {
+        parameterNames: "all" | "literals" | "none"
+        suppressWhenArgumentMatchesName: boolean
+    }
 }
 
 export function getExtensionSettings(
@@ -80,7 +86,13 @@ export async function getWorkspaceSettings(
         importStrategy: config.get<string>(`importStrategy`) ?? "useBundled",
         showNotifications: config.get<string>(`showNotifications`) ?? "off",
         formatter: config.get<boolean>(`formatter`) ?? true,
-        inlayHint: config.get<boolean>(`inlayHint`) ?? true
+        inlayHint: config.get<boolean>(`inlayHint`) ?? true,
+        inlayHints: {
+            parameterNames:
+                config.get<"all" | "literals" | "none">(`inlayHints.parameterNames`) ?? "all",
+            suppressWhenArgumentMatchesName:
+                config.get<boolean>(`inlayHints.suppressWhenArgumentMatchesName`) ?? true
+        }
     }
     return workspaceSetting
 }
@@ -113,7 +125,13 @@ export async function getGlobalSettings(
         importStrategy: getGlobalValue<string>(config, "importStrategy", "useBundled"),
         showNotifications: getGlobalValue<string>(config, "showNotifications", "off"),
         formatter: config.get<boolean>(`formatter`) ?? true,
-        inlayHint: config.get<boolean>(`inlayHint`) ?? true
+        inlayHint: config.get<boolean>(`inlayHint`) ?? true,
+        inlayHints: {
+            parameterNames:
+                config.get<"all" | "literals" | "none">(`inlayHints.parameterNames`) ?? "all",
+            suppressWhenArgumentMatchesName:
+                config.get<boolean>(`inlayHints.suppressWhenArgumentMatchesName`) ?? true
+        }
     }
     return setting
 }
@@ -129,7 +147,9 @@ export function checkIfConfigurationChanged(
         `${namespace}.importStrategy`,
         `${namespace}.showNotifications`,
         `${namespace}.formatter`,
-        `${namespace}.inlayHint`
+        `${namespace}.inlayHint`,
+        `${namespace}.inlayHints.parameterNames`,
+        `${namespace}.inlayHints.suppressWhenArgumentMatchesName`
     ]
     const changed = settings.map((s) => e.affectsConfiguration(s))
     return changed.includes(true)

client/src/extension.ts

@@ -13,7 +13,8 @@ import {
     isFirstLineMachine,
     diagnosticHandler,
     cdlDocumentSymbolProvider,
-    defDocumentSymbolProvider
+    defDocumentSymbolProvider,
+    definitionCdlEventHandler
 } from "./common/handlers"
 import { registerLogger, traceError, traceLog, traceVerbose } from "./common/log/logging"
 import {
@@ -23,7 +24,7 @@ import {
     onDidChangePythonInterpreter,
     resolveInterpreter
 } from "./common/python"
-import { restartServer } from "./common/server"
+import { disposeServerResources, restartServer } from "./common/server"
 import { checkIfConfigurationChanged, getInterpreterFromSetting } from "./common/settings"
 import { loadServerDefaults } from "./common/setup"
 import { getLSClientTraceLevel } from "./common/utilities"
@@ -37,6 +38,7 @@ export async function activate(context: vscode.ExtensionContext) {
     const serverInfo = loadServerDefaults()
     const serverName = serverInfo.name
     const serverId = serverInfo.module
+    const pythonDebugMode = process.env.USE_DEBUGPY?.toLowerCase() === "true"
 
     // Setup logging
     const outputChannel = createOutputChannel(serverName)
@@ -100,10 +102,15 @@ export async function activate(context: vscode.ExtensionContext) {
         return runServerQueue
     }
 
+    if (!pythonDebugMode) {
         context.subscriptions.push(
             onDidChangePythonInterpreter(async () => {
                 await runServer()
-        }),
+            })
+        )
+    }
+
+    context.subscriptions.push(
         onDidChangeConfiguration(async (e: vscode.ConfigurationChangeEvent) => {
             if (checkIfConfigurationChanged(e, serverId)) {
                 await runServer()
@@ -115,6 +122,15 @@ export async function activate(context: vscode.ExtensionContext) {
     )
 
     setImmediate(async () => {
+        if (pythonDebugMode) {
+            // A debugpy listen session is attached to exactly one process. Do not
+            // subscribe to interpreter changes during startup, as the Python
+            // extension can emit a duplicate event and restart that process.
+            traceLog("Python debug mode: starting one stable server session")
+            await runServer()
+            return
+        }
+
         const interpreter = getInterpreterFromSetting(serverId)
         if (interpreter === undefined || interpreter.length === 0) {
             traceLog(`Python extension loading`)
@@ -177,6 +193,16 @@ export async function activate(context: vscode.ExtensionContext) {
     )
     context.subscriptions.push(hoverCdlProvider)
 
+    const definitionCdlEventProvider = vscode.languages.registerDefinitionProvider(
+        { scheme: "file", language: "cdl" },
+        {
+            provideDefinition(document, position, token) {
+                return definitionCdlEventHandler(document, position, token)
+            }
+        }
+    )
+    context.subscriptions.push(definitionCdlEventProvider)
+
     const formatDefProvider = vscode.languages.registerDocumentFormattingEditProvider(
         { scheme: "file", language: "def" },
         {
@@ -220,33 +246,73 @@ export async function activate(context: vscode.ExtensionContext) {
     const diagnosticCollectionDef = vscode.languages.createDiagnosticCollection("def")
     context.subscriptions.push(diagnosticCollectionCdl, diagnosticCollectionDef)
 
-    // Check if the first line of the CDL file contains "MACHINE"
+    const diagnosticTimers = new Map<string, ReturnType<typeof setTimeout>>()
-    context.subscriptions.push(
+    const updateDiagnostics = (document: vscode.TextDocument) => {
-        vscode.workspace.onDidOpenTextDocument((document) => {
-            if (document.languageId === "cdl" || document.languageId === "def") {
         if (document.languageId === "cdl") {
             diagnosticCollectionCdl.set(document.uri, diagnosticHandler(document))
         } else if (document.languageId === "def") {
             diagnosticCollectionDef.set(document.uri, diagnosticHandler(document))
         }
     }
+    const scheduleDiagnostics = (document: vscode.TextDocument) => {
+        const key = document.uri.toString()
+        const previous = diagnosticTimers.get(key)
+        if (previous !== undefined) {
+            clearTimeout(previous)
+        }
+        diagnosticTimers.set(
+            key,
+            setTimeout(() => {
+                diagnosticTimers.delete(key)
+                updateDiagnostics(document)
+            }, 120)
+        )
+    }
+
+    // Check if the first line of the CDL file contains "MACHINE"
+    context.subscriptions.push(
+        vscode.workspace.onDidOpenTextDocument((document) => {
+            if (document.languageId === "cdl" || document.languageId === "def") {
+                updateDiagnostics(document)
+            }
         }),
         vscode.workspace.onDidChangeTextDocument((event) => {
             const document = event.document
             if (document.languageId === "cdl" || document.languageId === "def") {
-                if (document.languageId === "cdl") {
+                scheduleDiagnostics(document)
-                    diagnosticCollectionCdl.set(document.uri, diagnosticHandler(document))
+            }
-                } else if (document.languageId === "def") {
+        }),
-                    diagnosticCollectionDef.set(document.uri, diagnosticHandler(document))
+        vscode.workspace.onDidCloseTextDocument((document) => {
+            const key = document.uri.toString()
+            const timer = diagnosticTimers.get(key)
+            if (timer !== undefined) {
+                clearTimeout(timer)
+                diagnosticTimers.delete(key)
+            }
+            diagnosticCollectionCdl.delete(document.uri)
+            diagnosticCollectionDef.delete(document.uri)
+        }),
+        {
+            dispose() {
+                for (const timer of diagnosticTimers.values()) {
+                    clearTimeout(timer)
+                }
+                diagnosticTimers.clear()
             }
         }
-        })
     )
+
+    for (const document of vscode.workspace.textDocuments) {
+        if (document.languageId === "cdl" || document.languageId === "def") {
+            updateDiagnostics(document)
+        }
+    }
 }
 
 export function deactivate(): Thenable<void> | undefined {
     if (!client) {
+        disposeServerResources()
         return undefined
     }
-    return client.stop()
+    return client.stop().finally(disposeServerResources)
 }

esbuild.js

@@ -1,19 +1,21 @@
 const esbuild = require("esbuild")
+const path = require("path")
 
 const production = process.argv.includes("--production")
 const watch = process.argv.includes("--watch")
 
 async function main() {
     const ctx = await esbuild.context({
+        absWorkingDir: __dirname,
         entryPoints: ["client/src/extension.ts"],
         bundle: true,
         format: "cjs",
         minify: production,
         sourcemap: !production,
-        sourcesContent: false,
+        sourcesContent: !production,
         platform: "node",
         // outdir: "out",
-        outfile: "./dist/extension.js",
+        outfile: path.join(__dirname, "dist", "extension.js"),
         external: ["vscode"],
         logLevel: "silent",
         plugins: [

package.json

@@ -2,7 +2,7 @@
   "name": "nx-post-support",
   "displayName": "NX Postprocessor Support",
   "description": "VS Code extension for NX CAM postprocessor development with syntax highlighting, formatting, linting, and auto-completion for CDL, TCL, and DEF files",
-  "version": "2026.6.200",
+  "version": "2026.8.200",
   "publisher": "Christoph",
   "icon": "images/nx-1.png",
   "extensionDependencies": [
@@ -96,6 +96,26 @@
           "default": true,
           "description": "Use the Inlay Hints in from `NX Postprocessor Support`"
         },
+        "nx-post-support.inlayHints.parameterNames": {
+          "type": "string",
+          "default": "all",
+          "enum": [
+            "all",
+            "literals",
+            "none"
+          ],
+          "enumDescriptions": [
+            "Show parameter name hints for all arguments.",
+            "Show parameter name hints only for literal arguments.",
+            "Do not show parameter name hints."
+          ],
+          "description": "Controls which TCL procedure arguments receive parameter name hints."
+        },
+        "nx-post-support.inlayHints.suppressWhenArgumentMatchesName": {
+          "type": "boolean",
+          "default": true,
+          "description": "Hide a parameter hint when a variable argument already has the same name, for example `output` in `my_proc $output`."
+        },
         "nx-post-support.importStrategy": {
           "default": "useBundled",
           "description": "Defines where `NX Postprocessor Support` is imported from.",
@@ -120,10 +140,16 @@
           "type": "array"
         }
       }
+    },
+    "configurationDefaults": {
+      "[tcl]": {
+        "editor.inlayHints.maximumLength": 0
+      }
     }
   },
   "scripts": {
     "compile": "node esbuild.js --production",
+    "compile:debug": "node esbuild.js",
     "watch": "node esbuild.js --watch",
     "package": "node esbuild.js --production"
   },

server/src/_debug_server.py

@@ -6,6 +6,7 @@ import os
 import pathlib
 import runpy
 import sys
+import time
 
 
 def update_sys_path(path_to_add: str) -> None:
@@ -14,10 +15,43 @@ def update_sys_path(path_to_add: str) -> None:
         sys.path.append(path_to_add)
 
 
-# Ensure debugger is loaded before we load anything else, to debug initialization.
+def _debug_endpoint() -> tuple[str, int]:
-debugger_path = os.getenv("DEBUGPY_PATH", None)
+    host = os.getenv("NXPS_DEBUG_HOST", "127.0.0.1")
-if debugger_path:
+    raw_port = os.getenv("NXPS_DEBUG_PORT", "5678")
-    if debugger_path.endswith("debugpy"):
+    try:
+        port = int(raw_port)
+    except ValueError as error:
+        raise RuntimeError(f"Invalid NXPS_DEBUG_PORT: {raw_port!r}") from error
+    if not 1 <= port <= 65535:
+        raise RuntimeError(f"NXPS_DEBUG_PORT is outside the valid range: {port}")
+    return host, port
+
+
+def _connect_debugger(debugpy, host: str, port: int, timeout: float = 15.0) -> None:
+    deadline = time.monotonic() + timeout
+    last_error: OSError | None = None
+    while time.monotonic() < deadline:
+        try:
+            debugpy.connect((host, port))
+            debugpy.wait_for_client()
+            return
+        except (ConnectionRefusedError, OSError) as error:
+            last_error = error
+            time.sleep(0.25)
+
+    raise RuntimeError(
+        f"Could not connect debugpy to {host}:{port} within {timeout:.0f} seconds"
+    ) from last_error
+
+
+def main() -> None:
+    # Ensure debugger is loaded before we load anything else, so server
+    # initialization and module-level feature registration can be debugged.
+    debugger_path = os.getenv("DEBUGPY_PATH")
+    if not debugger_path:
+        raise RuntimeError("DEBUGPY_PATH is missing in Python debug mode")
+
+    if pathlib.Path(debugger_path).name.casefold() == "debugpy":
         debugger_path = os.fspath(pathlib.Path(debugger_path).parent)
 
     update_sys_path(debugger_path)
@@ -25,25 +59,14 @@ if debugger_path:
     # pylint: disable=wrong-import-position,import-error
     import debugpy
 
-    # 5678 is the default port, If you need to change it update it here
+    host, port = _debug_endpoint()
-    # and in launch.json.
+    print(f"debugpy: waiting for VS Code at {host}:{port}", file=sys.stderr)
-    # Connecting requires the "Python debug server" listener (launch.json) to be
+    _connect_debugger(debugpy, host, port)
-    # up first. If it isn't (e.g. wrong launch config was used), don't crash the
+    print("debugpy: VS Code attached; starting language server", file=sys.stderr)
-    # whole language server - just continue running without the debugger attached.
-    try:
-        debugpy.connect(5678)
-    except (ConnectionRefusedError, OSError) as exc:
-        print(
-            f"debugpy: could not connect to debug adapter on port 5678 "
-            f"({exc}); continuing without debugging.",
-            file=sys.stderr,
-        )
 
-    # This will ensure that execution is paused as soon as the debugger
+    server_path = os.fspath(pathlib.Path(__file__).parent / "lsp_server.py")
-    # connects to VS Code. If you don't want to pause here comment this
+    runpy.run_path(server_path, run_name="__main__")
-    # line and set breakpoints as appropriate.
-    # debugpy.breakpoint()
 
-SERVER_PATH = os.fspath(pathlib.Path(__file__).parent / "lsp_server.py")
+
-# NOTE: Set breakpoint in `lsp_server.py` before continuing.
+if __name__ == "__main__":
-runpy.run_path(SERVER_PATH, run_name="__main__")
+    main()

server/src/lsp_server.py

@@ -5,15 +5,15 @@
 from __future__ import annotations
 
 import json
+import operator
 import os
 import pathlib
 import re
 import sys
 import threading
-
+from collections import ChainMap
-from typing import Any, Optional
-import operator
 from functools import reduce
+from typing import Any, Optional
 
 
 # **********************************************************
@@ -40,15 +40,29 @@ update_sys_path(
 # pylint: disable=wrong-import-position,import-error
 import lsp_jsonrpc as jsonrpc
 import lsprotocol.types as lsp
-from pygls import uris, workspace
 from common.load_data import standard_items
-from tools.folding_ranges import build_folding_ranges
-from tools.semantic_tokens import _Highlighter, TOKEN_TYPES, TokenModifier
-from tools.completion_items import completion, remove_existing_items, remove_shared_keys
-from tools.inlay_hint import InlayHintGenerator
-from tools.file_sourcing import get_all_psc_files, read_psc_file
 from lsp_tclserver import TclLanguageServer
-
+from pygls import uris, workspace
+from pygls.workspace.text_document import TextDocument
+from tools.folding_ranges import build_folding_ranges
+from tools.inlay_hint import (
+    InlayHintGenerator,
+    build_builtin_inlay_signatures,
+)
+from tools.navigation import (
+    SymbolIdentity,
+    definition_identities,
+    matching_occurrences,
+    symbol_at_position,
+    workspace_symbols,
+)
+from tools.semantic_tokens import (
+    TOKEN_TYPE_INDEX,
+    TOKEN_TYPES,
+    TokenModifier,
+    _Highlighter,
+)
+from tools.signature_help import build_signature_help
 
 WORKSPACE_SETTINGS = {}
 GLOBAL_SETTINGS = {}
@@ -59,6 +73,29 @@ LSP_SERVER = TclLanguageServer(
     name="NX Postprocessor Support", version="0.0.1", max_workers=MAX_WORKERS
 )
 
+BUILTIN_PROC_NAMES = {
+    item.label
+    for item in standard_items.tcl_keyword_list + standard_items.nx_procs
+}
+BUILTIN_VARIABLE_NAMES = {item.label for item in standard_items.nx_variables}
+STATIC_COMPLETION_ITEMS = tuple(
+    standard_items.tcl_keyword_list
+    + standard_items.nx_procs
+    + standard_items.nx_variables
+)
+STATIC_COMPLETION_KEYS = frozenset(
+    (item.label, getattr(item, "kind", None)) for item in STATIC_COMPLETION_ITEMS
+)
+BUILTIN_INLAY_SIGNATURES = build_builtin_inlay_signatures(
+    standard_items.json_data.get("MOM_procs", [])
+)
+BUILTIN_HOVER_ITEMS = {}
+for _hover_item in (
+    standard_items.json_data.get("MOM_procs", [])
+    + standard_items.json_data.get("mom_variables", [])
+):
+    BUILTIN_HOVER_ITEMS.setdefault(_hover_item.get("label"), _hover_item)
+
 # **********************************************************
 # Tool specific code goes below this.
 # **********************************************************
@@ -77,28 +114,100 @@ LSP_SERVER = TclLanguageServer(
 def did_open(params: lsp.DidOpenTextDocumentParams) -> None:
     """LSP handler for textDocument/didOpen request."""
     document = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
-    LSP_SERVER.compute_diagnostics(document)
+    LSP_SERVER.clear_cache_for_uri(document.uri)
-    # Also update custom completion and proc docs for this file
+    LSP_SERVER.analyze_document_now(document)
-    LSP_SERVER.update_poco_completion_for_file(document)
 
 
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DID_SAVE)
 def did_save(params: lsp.DidSaveTextDocumentParams) -> None:
     """LSP handler for textDocument/didSave request."""
-    _ = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
+    document = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
+    LSP_SERVER.analyze_document_now(document)
 
 
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DID_CLOSE)
-def did_close(_: lsp.DidCloseTextDocumentParams) -> None:
+def did_close(params: lsp.DidCloseTextDocumentParams) -> None:
     """LSP handler for textDocument/didClose request."""
+    uri = params.text_document.uri
+    LSP_SERVER.remove_file_state(uri)
+    _index_tcl_file_from_disk(uri)
 
 
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DID_CHANGE)
 def did_change(params: lsp.DidChangeTextDocumentParams) -> None:
     """LSP handler for textDocument/didChange request"""
     document = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
-    LSP_SERVER.compute_diagnostics(document)
+    LSP_SERVER.clear_cache_for_uri(document.uri)
-    LSP_SERVER.update_poco_completion_for_file(document)
+    LSP_SERVER.schedule_document_analysis(document)
+
+
+FILE_OPERATION_OPTIONS = lsp.FileOperationRegistrationOptions(
+    filters=[
+        lsp.FileOperationFilter(
+            scheme="file",
+            pattern=lsp.FileOperationPattern(glob="**/*"),
+        )
+    ]
+)
+
+
+def _index_tcl_file_from_disk(uri: str) -> None:
+    if not uri.startswith("file:"):
+        return
+
+    path = pathlib.Path(uris.to_fs_path(uri))
+    if path.suffix.lower() != ".tcl" or not path.is_file():
+        return
+
+    try:
+        document = TextDocument(uri=uri, language_id="tcl")
+        LSP_SERVER.update_poco_completion_for_file(
+            document,
+            cache_tree=False,
+            require_file_exists=True,
+        )
+    except (OSError, UnicodeError) as error:
+        log_warning(f"Could not re-index {path}: {error}")
+
+
+@LSP_SERVER.feature(lsp.WORKSPACE_DID_DELETE_FILES, FILE_OPERATION_OPTIONS)
+def did_delete_files(params: lsp.DeleteFilesParams) -> None:
+    for deleted_file in params.files:
+        LSP_SERVER.remove_file_state(deleted_file.uri)
+
+
+@LSP_SERVER.feature(lsp.WORKSPACE_DID_RENAME_FILES, FILE_OPERATION_OPTIONS)
+def did_rename_files(params: lsp.RenameFilesParams) -> None:
+    for renamed_file in params.files:
+        old_path = pathlib.Path(uris.to_fs_path(renamed_file.old_uri))
+        new_path = pathlib.Path(uris.to_fs_path(renamed_file.new_uri))
+        indexed_paths = LSP_SERVER.indexed_paths_under_uri(renamed_file.old_uri)
+        new_index_paths: set[pathlib.Path] = set()
+
+        for indexed_path in indexed_paths:
+            if LSP_SERVER.paths_equal(indexed_path, old_path):
+                new_index_paths.add(new_path)
+            else:
+                relative_path = os.path.relpath(indexed_path, old_path)
+                new_index_paths.add(new_path / relative_path)
+
+        # Also handles renaming a previously unindexed file to a TCL file.
+        if new_path.suffix.lower() == ".tcl":
+            new_index_paths.add(new_path)
+
+        LSP_SERVER.remove_file_state(renamed_file.old_uri)
+        for new_index_path in new_index_paths:
+            _index_tcl_file_from_disk(new_index_path.as_uri())
+
+
+@LSP_SERVER.feature(lsp.WORKSPACE_DID_CHANGE_WATCHED_FILES)
+def did_change_watched_files(params: lsp.DidChangeWatchedFilesParams) -> None:
+    """Keep indexes for closed Tcl files synchronized with disk changes."""
+    for change in params.changes:
+        if change.type == lsp.FileChangeType.Deleted:
+            LSP_SERVER.remove_file_state(change.uri)
+        else:
+            _index_tcl_file_from_disk(change.uri)
 
 
 @LSP_SERVER.feature(
@@ -111,13 +220,20 @@ def did_change(params: lsp.DidChangeTextDocumentParams) -> None:
 )
 def document_diagnostic(params: lsp.DocumentDiagnosticParams):
     """Return diagnostics for the requested document"""
-    was_cached = True
+    uri = params.text_document.uri
-    if (uri := params.text_document.uri) not in LSP_SERVER.diagnostics:
-        was_cached = False
     doc = LSP_SERVER.workspace.get_text_document(uri)
+    diagnostic_state = LSP_SERVER.diagnostic_snapshot(uri)
+    was_cached = (
+        diagnostic_state is not None and diagnostic_state[0] == doc.version
+    )
+    if not was_cached:
         LSP_SERVER.compute_diagnostics(doc)
+        diagnostic_state = LSP_SERVER.diagnostic_snapshot(uri)
 
-    version, diagnostics = LSP_SERVER.diagnostics[uri]
+    if diagnostic_state is None:
+        return lsp.FullDocumentDiagnosticReport(items=[])
+
+    version, diagnostics = diagnostic_state
     result_id = f"{uri}@{version}"
 
     if was_cached and result_id == params.previous_result_id:
@@ -128,23 +244,15 @@ def document_diagnostic(params: lsp.DocumentDiagnosticParams):
 
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_COMPLETION)
 def on_completion(params: lsp.CompletionParams) -> lsp.CompletionList:
-    from tools.variable_index import build_variable_index
     from tools.completion_items import BUILTIN_VAR_LABELS
 
     doc = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
 
-    # Base items
+    workspace_items = LSP_SERVER.completion_items_snapshot()
-    poco = [item for items in LSP_SERVER.poco_completion.values() for item in items]
-    base_items = (
-        standard_items.tcl_keyword_list
-        + standard_items.nx_procs
-        + standard_items.nx_variables
-        + poco
-    )
-
-    # Build variable index from current document
     tree = LSP_SERVER.get_tree(doc)
-    globals_set, procs_locals, proc_ranges = build_variable_index(doc.source, tree)
+    globals_set, procs_locals, proc_ranges = LSP_SERVER.variable_index_for_document(
+        doc, tree
+    )
 
     # Always include globals (excluding built-ins)
     dynamic_items = []
@@ -169,19 +277,47 @@ def on_completion(params: lsp.CompletionParams) -> lsp.CompletionList:
                         )
                 break
 
-    # Merge with de-duplication for variables only
+    # Merge with de-duplication. Each file keeps its complete index, so a proc
-    merged: list[lsp.CompletionItem] = []
+    # declared in multiple files must only appear once in the completion list.
-    seen_var_labels: set[str] = set()
+    merged: list[lsp.CompletionItem] = list(STATIC_COMPLETION_ITEMS)
-    for it in base_items + dynamic_items:
+    seen_items: set[tuple[str, lsp.CompletionItemKind | None]] = set(
-        if getattr(it, "kind", None) == lsp.CompletionItemKind.Variable:
+        STATIC_COMPLETION_KEYS
-            if it.label in seen_var_labels:
+    )
+    for it in (*workspace_items, *dynamic_items):
+        key = (it.label, getattr(it, "kind", None))
+        if key in seen_items:
             continue
-            seen_var_labels.add(it.label)
+        seen_items.add(key)
         merged.append(it)
 
     return lsp.CompletionList(is_incomplete=False, items=merged)
 
 
+@LSP_SERVER.feature(
+    lsp.TEXT_DOCUMENT_SIGNATURE_HELP,
+    lsp.SignatureHelpOptions(
+        trigger_characters=[" "],
+        retrigger_characters=[" "],
+    ),
+)
+def signature_help(params: lsp.SignatureHelpParams) -> lsp.SignatureHelp | None:
+    document = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
+    tree = LSP_SERVER.get_tree(document)
+
+    custom_signatures, custom_docs = LSP_SERVER.proc_metadata_snapshot(
+        document.path
+    )
+
+    return build_signature_help(
+        document.source,
+        tree,
+        params.position,
+        custom_signatures,
+        custom_docs,
+        standard_items.json_data.get("MOM_procs", []),
+    )
+
+
 # @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DOCUMENT_SYMBOL)
 # def document_symbols(params: lsp.DocumentSymbolParams):
 #     doc = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
@@ -201,21 +337,37 @@ def document_symbols(params: lsp.DocumentSymbolParams):
 
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_INLAY_HINT)
 def inlay_hints(params: lsp.InlayHintParams):
-    if not GLOBAL_SETTINGS.get("inlayHint", False):
-        return []
     document = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
+    settings = _get_settings_by_document(document)
+    if not settings.get("inlayHint", False):
+        return []
+
+    inlay_settings = settings.get("inlayHints", {})
+    parameter_names = inlay_settings.get("parameterNames", "all")
+    if parameter_names == "none":
+        return []
 
     # Reuse cached AST
     tree = LSP_SERVER.get_tree(document)
 
-    # Merge proc signatures across files and traverse once
+    # Built-in NX procedures are the fallback. Workspace procedures replace them,
-    merged_signatures = {}
+    # and a declaration in the current file wins over duplicate workspace names.
-    for sigs in LSP_SERVER.proc_signatures.values():
+    custom_signatures = LSP_SERVER.custom_inlay_signatures_snapshot(
-        merged_signatures.update(sigs)
+        document.path
+    )
+    signatures = ChainMap(custom_signatures, BUILTIN_INLAY_SIGNATURES)
 
-    generator = InlayHintGenerator(merged_signatures)
+    generator = InlayHintGenerator(
-    tree.accept(generator, recurse=True)
+        document.source,
-    return generator.hints
+        signatures,
+        source_lines=LSP_SERVER.get_lines(document),
+        requested_range=params.range,
+        parameter_names=parameter_names,
+        suppress_when_argument_matches_name=inlay_settings.get(
+            "suppressWhenArgumentMatchesName", True
+        ),
+    )
+    return generator.generate(tree)
 
 
 @LSP_SERVER.feature(
@@ -230,7 +382,7 @@ def semantic_tokens(params: lsp.SemanticTokensParams):
 
     data = []
     plugins = []
-    hl = _Highlighter(plugins, LSP_SERVER.poco_completion)
+    hl = _Highlighter(plugins, LSP_SERVER.custom_function_names_snapshot())
 
     # Reuse cached AST
     tree = LSP_SERVER.get_tree(document)
@@ -243,7 +395,7 @@ def semantic_tokens(params: lsp.SemanticTokensParams):
                 token.line,
                 token.offset,
                 token.length,
-                TOKEN_TYPES.index(token.tok_type),
+                TOKEN_TYPE_INDEX[token.tok_type],
                 reduce(operator.or_, token.tok_modifiers, 0),
             ]
         )
@@ -265,14 +417,14 @@ def hover(params: lsp.HoverParams) -> lsp.Hover:
     col = params.position.character
 
     try:
-        line = document.lines[pos.line]
+        line = LSP_SERVER.get_lines(document)[pos.line]
     except IndexError:
         return None
 
     # Do not show hover for proc name in its declaration
-    from tools.proc_docs import is_proc_declaration_position
+    from tools.proc_docs import is_proc_declaration_line
 
-    if is_proc_declaration_position(document.source, pos.line, pos.character):
+    if is_proc_declaration_line(line, pos.character):
         return None
 
     # Identify the token under the cursor
@@ -284,11 +436,7 @@ def hover(params: lsp.HoverParams) -> lsp.Hover:
         return None
 
     # 1) If token is a known MOM proc/variable, return built-in hover
-    command = token
+    match = BUILTIN_HOVER_ITEMS.get(token)
-    data = standard_items.json_data
-    all_items = data.get("MOM_procs", []) + data.get("mom_variables", [])
-
-    match = next((item for item in all_items if item["label"] == command), None)
     if match and match.get("kind") == "function":
         label = match.get("label", "")
         parameters = match.get("parameters", [])
@@ -321,13 +469,10 @@ def hover(params: lsp.HoverParams) -> lsp.Hover:
 
     # 2) Otherwise, check if the token is a custom proc and show its preceding doc block
     # Build a merged map of proc -> docs gathered during initialization and updates
-    proc_docs: dict[str, str] = {}
+    proc_doc = LSP_SERVER.proc_documentation(token, document.path)
-    for file_docs in LSP_SERVER.proc_docs.values():
+    if proc_doc is not None:
-        proc_docs.update(file_docs)
-
-    if token in proc_docs:
         return lsp.Hover(
-            lsp.MarkupContent(kind=lsp.MarkupKind.Markdown, value=proc_docs[token])
+            lsp.MarkupContent(kind=lsp.MarkupKind.Markdown, value=proc_doc)
         )
 
     return None
@@ -335,73 +480,153 @@ def hover(params: lsp.HoverParams) -> lsp.Hover:
 
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DEFINITION)
 def goto_definition(params: lsp.DefinitionParams):
-    """Provide go-to-definition locations for Tcl procs.
+    """Resolve Tcl proc and variable definitions through the symbol index."""
-
+    context = _navigation_context(params.text_document.uri, params.position)
-    Strategy:
+    if context is None:
-    - Find the token under the cursor.
-    - If it matches a custom proc collected in proc_signatures, locate its declaration
-      by searching the current document first, then other indexed files.
-    - Return a Location pointing to the proc name in its declaration line.
-    """
-    doc = LSP_SERVER.workspace.get_text_document(params.text_document.uri)
-    pos = params.position
-    try:
-        line = doc.lines[pos.line]
-    except IndexError:
         return None
 
-    # Identify token under cursor
+    indexes, definitions, _, identity = context
-    token = None
+    locations = [
-    for m in re.finditer(r"\b\w+\b", line):
+        lsp.Location(uri=index.uri, range=occurrence.range)
-        if m.start() <= pos.character <= m.end():
+        for index, occurrence in matching_occurrences(
-            token = m.group(0)
+            identity, indexes, definitions
-            break
+        )
-    if not token:
+        if occurrence.is_definition
+    ]
+    return _sorted_locations(locations) or None
+
+
+def _navigation_context(uri: str, position: lsp.Position):
+    indexes = LSP_SERVER.navigation_snapshot()
+    filepath = str(pathlib.Path(uris.to_fs_path(uri)))
+    index = indexes.get(filepath)
+    if index is None or LSP_SERVER.index_update_pending(filepath):
+        document = LSP_SERVER.workspace.get_text_document(uri)
+        LSP_SERVER.update_poco_completion_for_file(document)
+        indexes = LSP_SERVER.navigation_snapshot()
+        index = indexes.get(filepath)
+    if index is None:
         return None
 
-    # Helper to search a single source text for a proc declaration
+    definitions = definition_identities(indexes)
-    def find_decl_in_source(source_text: str, uri: str) -> Optional[lsp.Location]:
+    result = symbol_at_position(index, position, definitions)
-        lines = source_text.split("\n")
+    if result is None:
-        pattern = re.compile(r"^\s*proc\s+" + re.escape(token) + r"\b")
+        return None
-        for i, ln in enumerate(lines):
+    occurrence, identity = result
-            m = pattern.match(ln)
+    return indexes, definitions, occurrence, identity
-            if m:
+
-                start_char = ln.find(token)
+
-                if start_char < 0:
+def _sorted_locations(locations: list[lsp.Location]) -> list[lsp.Location]:
-                    start_char = max(m.end() - len(token), 0)
+    return sorted(
-                start = lsp.Position(i, start_char)
+        locations,
-                end = lsp.Position(i, start_char + len(token))
+        key=lambda location: (
-                return lsp.Location(uri=uri, range=lsp.Range(start=start, end=end))
+            location.uri,
+            location.range.start.line,
+            location.range.start.character,
+        ),
+    )
+
+
+@LSP_SERVER.feature(lsp.TEXT_DOCUMENT_REFERENCES)
+def references(params: lsp.ReferenceParams) -> list[lsp.Location]:
+    context = _navigation_context(params.text_document.uri, params.position)
+    if context is None:
+        return []
+
+    indexes, definitions, _, identity = context
+    locations = [
+        lsp.Location(uri=index.uri, range=occurrence.range)
+        for index, occurrence in matching_occurrences(
+            identity, indexes, definitions
+        )
+        if params.context.include_declaration or not occurrence.is_definition
+    ]
+    return _sorted_locations(locations)
+
+
+def _is_renamable(
+    identity: SymbolIdentity,
+    indexes,
+    definitions: set[SymbolIdentity],
+) -> bool:
+    if identity not in definitions or identity.kind not in {"proc", "variable"}:
+        return False
+
+    basename = identity.name.rsplit("::", 1)[-1]
+    if identity.kind == "proc":
+        if basename in BUILTIN_PROC_NAMES:
+            return False
+        definition_count = sum(
+            occurrence.is_definition and occurrence.identity == identity
+            for index in indexes.values()
+            for occurrence in index.occurrences
+        )
+        return definition_count == 1
+
+    return basename not in BUILTIN_VARIABLE_NAMES
+
+
+@LSP_SERVER.feature(lsp.TEXT_DOCUMENT_PREPARE_RENAME)
+def prepare_rename(params: lsp.PrepareRenameParams):
+    context = _navigation_context(params.text_document.uri, params.position)
+    if context is None:
         return None
 
-    # 1) Search in current document
+    indexes, definitions, occurrence, identity = context
-    loc = find_decl_in_source(doc.source, doc.uri)
+    if not _is_renamable(identity, indexes, definitions):
-    if loc:
+        return None
-        return loc
+    return lsp.PrepareRenameResult_Type1(
+        range=occurrence.range, placeholder=occurrence.placeholder
+    )
 
-    # 2) Search in indexed files from proc_signatures
-    # Build list of candidate files that declare this token as a proc
-    candidate_files: list[str] = []
-    for file_path, procs in LSP_SERVER.proc_signatures.items():
-        if token in procs:
-            candidate_files.append(file_path)
 
-    for fp in candidate_files:
+@LSP_SERVER.feature(
-        uri = pathlib.Path(fp).as_uri()
+    lsp.TEXT_DOCUMENT_RENAME,
-        # Try to get from workspace if available; else read from disk
+    lsp.RenameOptions(prepare_provider=True),
-        try:
+)
-            other_doc = LSP_SERVER.workspace.get_text_document(uri)
+def rename(params: lsp.RenameParams) -> lsp.WorkspaceEdit | None:
-            source = other_doc.source
+    if not re.fullmatch(r"[A-Za-z_][A-Za-z0-9_]*", params.new_name):
-        except Exception:
+        return None
-            try:
+
-                source = pathlib.Path(fp).read_text(encoding="utf-8")
+    context = _navigation_context(params.text_document.uri, params.position)
-            except Exception:
+    if context is None:
+        return None
+
+    indexes, definitions, _, identity = context
+    if not _is_renamable(identity, indexes, definitions):
+        return None
+
+    changes: dict[str, list[lsp.TextEdit]] = {}
+    seen = set()
+    for index, occurrence in matching_occurrences(identity, indexes, definitions):
+        key = (
+            index.uri,
+            occurrence.range.start.line,
+            occurrence.range.start.character,
+            occurrence.range.end.line,
+            occurrence.range.end.character,
+        )
+        if key in seen:
             continue
-        loc = find_decl_in_source(source, uri)
+        seen.add(key)
-        if loc:
+        changes.setdefault(index.uri, []).append(
-            return loc
+            lsp.TextEdit(range=occurrence.range, new_text=params.new_name)
+        )
 
-    return None
+    for edits in changes.values():
+        edits.sort(
+            key=lambda edit: (
+                edit.range.start.line,
+                edit.range.start.character,
+            ),
+            reverse=True,
+        )
+    return lsp.WorkspaceEdit(changes=changes)
+
+
+@LSP_SERVER.feature(lsp.WORKSPACE_SYMBOL)
+def workspace_symbol(params: lsp.WorkspaceSymbolParams):
+    return workspace_symbols(LSP_SERVER.navigation_snapshot(), params.query)
 
 
 # **********************************************************
@@ -476,6 +701,9 @@ def initialize(params: lsp.InitializeParams) -> lsp.InitializeResult:
                 legend=semantic_tokens_legend, full=True, range=False
             ),
             definition_provider=True,
+            references_provider=True,
+            rename_provider=lsp.RenameOptions(prepare_provider=True),
+            workspace_symbol_provider=True,
         )
     )
 
@@ -486,48 +714,43 @@ def initialized(_params: lsp.InitializedParams):
 
     def index_workspace():
         try:
-            root = LSP_SERVER.workspace.root_path
-            log_to_output("Background indexing started...")
-            psc_files = get_all_psc_files(pathlib.Path(root))
-            for psc_file in psc_files:
-                poco_files = read_psc_file(psc_file)
-                for sourced_layer in poco_files:
-                    completion.reset()
             try:
-                        file_root = pathlib.Path(root).joinpath(
+                root = LSP_SERVER.workspace.root_path
-                            sourced_layer.subfolder if sourced_layer.subfolder else ""
+            except RuntimeError:
+                root = None
+            if not root:
+                log_to_output("Background indexing skipped: no workspace folder is open.")
+                return
+            log_to_output("Background indexing started...")
+            root_path = pathlib.Path(root)
+            skipped_directories = {
+                ".git",
+                ".nox",
+                ".venv",
+                "dist",
+                "node_modules",
+                "out",
+            }
+            tcl_files = (
+                path
+                for path in root_path.rglob("*.tcl")
+                if not any(
+                    part.casefold() in skipped_directories
+                    for part in path.relative_to(root_path).parts[:-1]
                 )
-                        for tcl_file in sourced_layer.files:
-                            filepath = pathlib.Path(file_root).joinpath(
-                                f"{tcl_file}.tcl"
             )
-                            if not filepath.exists():
+            for filepath in sorted(tcl_files, key=lambda path: str(path).casefold()):
-                                continue
+                try:
-                            completion.reset()
+                    document = TextDocument(
-                            document = LSP_SERVER.workspace.get_text_document(
+                        uri=filepath.as_uri(), language_id="tcl"
-                                filepath.as_uri()
                     )
-                            tree = LSP_SERVER.parser.parse(document.source)
+                    LSP_SERVER.update_poco_completion_for_file(
-                            tree.accept(completion, recurse=True)
+                        document,
-                            remove_existing_items(
+                        cache_tree=False,
-                                completion.custom_functions, LSP_SERVER.poco_completion
+                        require_file_exists=True,
                     )
-                            LSP_SERVER.poco_completion[str(filepath)] = (
+                except Exception as error:
-                                completion.custom_functions
+                    log_to_output(f"Fehler beim Parsen von {filepath}: {error}")
-                            )
-                            remove_shared_keys(
-                                LSP_SERVER.proc_signatures, completion.proc_signatures
-                            )
-                            LSP_SERVER.proc_signatures[str(filepath)] = (
-                                completion.proc_signatures
-                            )
-                            from tools.proc_docs import build_proc_docs
-
-                            LSP_SERVER.proc_docs[str(filepath)] = build_proc_docs(
-                                tree, document.source
-                            )
-                    except Exception as e:
-                        log_to_output(f"Fehler beim Parsen von {filepath}: {e}")
             log_to_output("Background indexing completed.")
         except Exception as e:
             log_to_output(f"Background indexing failed: {e}")
@@ -556,6 +779,13 @@ def _get_global_defaults():
         "showNotifications": GLOBAL_SETTINGS.get("showNotifications", "off"),
         "formatter": GLOBAL_SETTINGS.get("formatter", True),
         "inlayHint": GLOBAL_SETTINGS.get("inlayHint", True),
+        "inlayHints": GLOBAL_SETTINGS.get(
+            "inlayHints",
+            {
+                "parameterNames": "all",
+                "suppressWhenArgumentMatchesName": True,
+            },
+        ),
     }
 
 

server/src/lsp_tclserver.py

@@ -1,20 +1,26 @@
 import logging
+import os
 import pathlib
+import threading
 from typing import List, Optional, Tuple
-import lsprotocol.types as lsp
-from pygls.workspace.text_document import TextDocument
-from tclint.lexer import TclSyntaxError
-from tclint.format import FormatterOpts
-from tools.formatter import NxFormatter as Formatter
-from tclint.violations import Violation
-from plugins.poco_plugin import commands
-from tools import checks, parser
-from pygls import server, uris
-from tools.completion_items import completion, remove_existing_items, remove_shared_keys
-from tools.proc_docs import build_proc_docs
 
+import lsprotocol.types as lsp
+from plugins.poco_plugin import commands
+from pygls import server, uris
+from pygls.workspace.text_document import TextDocument
+from tclint.format import FormatterOpts
+from tclint.lexer import TclSyntaxError
+from tclint.violations import Violation
+from tools import checks, parser
+from tools.completion_items import CompletionCollector
+from tools.formatter import NxFormatter as Formatter
+from tools.inlay_hint import InlayHintSignature, build_custom_inlay_signatures
+from tools.navigation import FileSymbolIndex, build_file_symbol_index
+from tools.proc_docs import build_proc_docs
+from tools.variable_index import ProcRange, build_variable_index
 
 DIAGNOSTIC_SOURCE = "nx-post-support"
+LOGGER = logging.getLogger(__name__)
 
 
 class TclLanguageServer(server.LanguageServer):
@@ -27,62 +33,530 @@ class TclLanguageServer(server.LanguageServer):
         self.poco_completion: dict = {}
         self.proc_signatures: dict = {}
         self.proc_docs: dict = {}
+        self.navigation_indexes: dict[str, FileSymbolIndex] = {}
+        self.variable_indexes: dict[
+            str,
+            tuple[
+                int | None,
+                tuple[set[str], dict[str, set[str]], list[ProcRange]],
+            ],
+        ] = {}
         # Cache: (uri, version) -> (tree, violations)
         self._ast_cache = {}
+        self._line_cache: dict[tuple[str, int | None], tuple[str, ...]] = {}
+        self._parser_lock = threading.RLock()
+        self._index_lock = threading.RLock()
+        self._index_tokens: dict[str, int] = {}
+        self._index_versions: dict[str, int | None] = {}
+        self._committed_index_versions: dict[str, int | None] = {}
+        self._next_index_token = 0
+        self._diagnostic_tokens: dict[str, int] = {}
+        self._next_diagnostic_token = 0
+        self._index_generation = 0
+        self._workspace_completion_cache: tuple[int, tuple] = (-1, ())
+        self._custom_function_names_cache: tuple[int, frozenset[str]] = (
+            -1,
+            frozenset(),
+        )
+        self._proc_metadata_cache: dict[
+            str, tuple[int, dict[str, list[str]], dict[str, str]]
+        ] = {}
+        self._custom_inlay_cache: dict[
+            str, tuple[int, dict[str, InlayHintSignature]]
+        ] = {}
+        self._analysis_lock = threading.RLock()
+        self._analysis_timers: dict[str, threading.Timer] = {}
+        self._analysis_tokens: dict[str, int] = {}
+        self._next_analysis_token = 0
+
+    def _parse_source(self, source: str):
+        self.parser.violations = []
+        tree = self.parser.parse(source)
+        return tree, list(self.parser.violations)
+
+    def parse_source(self, source: str):
+        """Parse without retaining an AST, serialized around the shared parser."""
+        with self._parser_lock:
+            tree, _ = self._parse_source(source)
+            return tree
 
     def get_tree(self, document: TextDocument):
         key = (document.uri, document.version)
+        with self._parser_lock:
             cached = self._ast_cache.get(key)
-        if cached:
+            if cached is not None:
                 return cached[0]
-        # Parse and cache
+            tree, violations = self._parse_source(document.source)
-        self.parser.violations = []
-        tree = self.parser.parse(document.source)
-        violations = list(self.parser.violations)
             self._ast_cache[key] = (tree, violations)
             return tree
 
     def get_tree_and_violations(self, document: TextDocument):
         key = (document.uri, document.version)
+        with self._parser_lock:
             cached = self._ast_cache.get(key)
-        if cached:
+            if cached is not None:
                 return cached
-        # Parse and cache
+            tree, violations = self._parse_source(document.source)
-        self.parser.violations = []
-        tree = self.parser.parse(document.source)
-        violations = list(self.parser.violations)
             self._ast_cache[key] = (tree, violations)
             return tree, violations
 
-    def clear_cache_for_uri(self, uri: str):
+    def get_lines(self, document: TextDocument) -> tuple[str, ...]:
-        to_delete = [k for k in self._ast_cache.keys() if k[0] == uri]
+        """Return split source lines once per document version."""
-        for k in to_delete:
+        key = (document.uri, document.version)
-            del self._ast_cache[k]
+        with self._parser_lock:
+            lines = self._line_cache.get(key)
+            if lines is None:
+                lines = tuple(document.source.splitlines())
+                self._line_cache[key] = lines
+            return lines
 
-    def update_poco_completion_for_file(self, document: TextDocument):
+    def clear_cache_for_uri(self, uri: str):
+        with self._parser_lock:
+            to_delete = [key for key in self._ast_cache if key[0] == uri]
+            for key in to_delete:
+                del self._ast_cache[key]
+            for key in list(self._line_cache):
+                if key[0] == uri:
+                    del self._line_cache[key]
+
+    @staticmethod
+    def _normalized_path(path: pathlib.Path | str) -> str:
+        return os.path.normcase(os.path.abspath(os.fspath(path)))
+
+    @classmethod
+    def _is_same_or_child(
+        cls, candidate: pathlib.Path | str, parent: pathlib.Path | str
+    ) -> bool:
+        candidate_path = cls._normalized_path(candidate)
+        parent_path = cls._normalized_path(parent)
+        try:
+            return os.path.commonpath([candidate_path, parent_path]) == parent_path
+        except ValueError:
+            return False
+
+    @classmethod
+    def paths_equal(
+        cls, first: pathlib.Path | str, second: pathlib.Path | str
+    ) -> bool:
+        return cls._normalized_path(first) == cls._normalized_path(second)
+
+    def _invalidate_workspace_caches_locked(self) -> None:
+        """Invalidate request-level aggregates after an index mutation."""
+        self._index_generation += 1
+        self._workspace_completion_cache = (-1, ())
+        self._custom_function_names_cache = (-1, frozenset())
+        self._proc_metadata_cache.clear()
+        self._custom_inlay_cache.clear()
+
+    def completion_items_snapshot(self) -> tuple:
+        """Return de-duplicated workspace completion items, cached by generation."""
+        with self._index_lock:
+            generation, items = self._workspace_completion_cache
+            if generation == self._index_generation:
+                return items
+
+            merged = []
+            seen = set()
+            for path_items in self.poco_completion.values():
+                for item in path_items:
+                    key = (item.label, getattr(item, "kind", None))
+                    if key in seen:
+                        continue
+                    seen.add(key)
+                    merged.append(item)
+
+            items = tuple(merged)
+            self._workspace_completion_cache = (self._index_generation, items)
+            return items
+
+    def custom_function_names_snapshot(self) -> frozenset[str]:
+        """Return custom completion labels for semantic highlighting."""
+        with self._index_lock:
+            generation, names = self._custom_function_names_cache
+            if generation == self._index_generation:
+                return names
+
+            names = frozenset(
+                item.label
+                for path_items in self.poco_completion.values()
+                for item in path_items
+            )
+            self._custom_function_names_cache = (self._index_generation, names)
+            return names
+
+    def proc_metadata_snapshot(
+        self, current_path: pathlib.Path | str
+    ) -> tuple[dict[str, list[str]], dict[str, str]]:
+        """Return merged proc metadata, preferring declarations in the active file."""
+        normalized_current = self._normalized_path(current_path)
+        with self._index_lock:
+            cached = self._proc_metadata_cache.get(normalized_current)
+            if cached is not None and cached[0] == self._index_generation:
+                return cached[1], cached[2]
+
+            signatures: dict[str, list[str]] = {}
+            docs: dict[str, str] = {}
+            signature_paths = sorted(
+                self.proc_signatures,
+                key=lambda path: self._normalized_path(path).casefold(),
+            )
+            doc_paths = sorted(
+                self.proc_docs,
+                key=lambda path: self._normalized_path(path).casefold(),
+            )
+
+            for path in signature_paths:
+                if self._normalized_path(path) != normalized_current:
+                    signatures.update(self.proc_signatures[path])
+            for path in signature_paths:
+                if self._normalized_path(path) == normalized_current:
+                    signatures.update(self.proc_signatures[path])
+
+            for path in doc_paths:
+                if self._normalized_path(path) != normalized_current:
+                    docs.update(self.proc_docs[path])
+            for path in doc_paths:
+                if self._normalized_path(path) == normalized_current:
+                    docs.update(self.proc_docs[path])
+
+            cached_value = (self._index_generation, signatures, docs)
+            self._proc_metadata_cache[normalized_current] = cached_value
+            return signatures, docs
+
+    def proc_documentation(
+        self, name: str, current_path: pathlib.Path | str
+    ) -> str | None:
+        _, docs = self.proc_metadata_snapshot(current_path)
+        return docs.get(name)
+
+    def custom_inlay_signatures_snapshot(
+        self, current_path: pathlib.Path | str
+    ) -> dict[str, InlayHintSignature]:
+        """Return custom inlay signatures cached until the workspace index changes."""
+        normalized_current = self._normalized_path(current_path)
+        with self._index_lock:
+            cached = self._custom_inlay_cache.get(normalized_current)
+            if cached is not None and cached[0] == self._index_generation:
+                return cached[1]
+
+            signatures = build_custom_inlay_signatures(
+                self.proc_signatures,
+                self.proc_docs,
+                self.navigation_indexes,
+                os.fspath(current_path),
+            )
+            self._custom_inlay_cache[normalized_current] = (
+                self._index_generation,
+                signatures,
+            )
+            return signatures
+
+    def variable_index_for_document(
+        self, document: TextDocument, tree=None
+    ) -> tuple[set[str], dict[str, set[str]], list[ProcRange]]:
+        """Return the per-version variable index used by completion requests."""
+        filepath = str(pathlib.Path(uris.to_fs_path(document.uri)))
+        with self._index_lock:
+            cached = self.variable_indexes.get(filepath)
+            if cached is not None and cached[0] == document.version:
+                return cached[1]
+
+        if tree is None:
+            tree = self.get_tree(document)
+        variable_index = build_variable_index(document.source, tree)
+
+        with self._index_lock:
+            cached = self.variable_indexes.get(filepath)
+            if (
+                cached is None
+                or cached[0] is None
+                or document.version is None
+                or cached[0] <= document.version
+            ):
+                self.variable_indexes[filepath] = (document.version, variable_index)
+                return variable_index
+            return cached[1]
+
+    def index_is_current(self, document: TextDocument) -> bool:
+        filepath = str(pathlib.Path(uris.to_fs_path(document.uri)))
+        with self._index_lock:
+            return (
+                filepath in self._committed_index_versions
+                and self._committed_index_versions[filepath] == document.version
+            )
+
+    def index_update_pending(self, filepath: pathlib.Path | str) -> bool:
+        filepath = os.fspath(filepath)
+        with self._index_lock:
+            return (
+                filepath not in self._committed_index_versions
+                or self._index_versions.get(filepath)
+                != self._committed_index_versions[filepath]
+            )
+
+    def _cancel_document_analysis(self, uri: str) -> None:
+        with self._analysis_lock:
+            timer = self._analysis_timers.pop(uri, None)
+            self._analysis_tokens.pop(uri, None)
+        if timer is not None:
+            timer.cancel()
+
+    def cancel_analysis_under_uri(self, uri: str) -> None:
+        """Cancel delayed analysis for a closed/deleted file or folder."""
+        try:
+            target = pathlib.Path(uris.to_fs_path(uri))
+        except (TypeError, ValueError):
+            self._cancel_document_analysis(uri)
+            return
+
+        with self._analysis_lock:
+            matching_uris = []
+            for pending_uri in self._analysis_timers:
+                try:
+                    pending_path = pathlib.Path(uris.to_fs_path(pending_uri))
+                except (TypeError, ValueError):
+                    continue
+                if self._is_same_or_child(pending_path, target):
+                    matching_uris.append(pending_uri)
+
+            timers = [self._analysis_timers.pop(key) for key in matching_uris]
+            for key in matching_uris:
+                self._analysis_tokens.pop(key, None)
+
+        for timer in timers:
+            timer.cancel()
+
+    def _invalidate_document_work(self, document: TextDocument) -> None:
+        """Prevent older diagnostic/index work from committing after a new edit."""
+        filepath = str(pathlib.Path(uris.to_fs_path(document.uri)))
+        with self._index_lock:
+            self._next_diagnostic_token += 1
+            self._diagnostic_tokens[document.uri] = self._next_diagnostic_token
+            self._next_index_token += 1
+            self._index_tokens[filepath] = self._next_index_token
+            self._index_versions[filepath] = document.version
+
+    def schedule_document_analysis(
+        self, document: TextDocument, delay_seconds: float = 0.15
+    ) -> None:
+        """Coalesce rapid edits and analyze only the latest immutable snapshot."""
+        snapshot = TextDocument(
+            uri=document.uri,
+            source=document.source,
+            version=document.version,
+            language_id=document.language_id,
+        )
+        self._invalidate_document_work(snapshot)
+
+        with self._analysis_lock:
+            previous = self._analysis_timers.pop(snapshot.uri, None)
+            if previous is not None:
+                previous.cancel()
+
+            self._next_analysis_token += 1
+            token = self._next_analysis_token
+            self._analysis_tokens[snapshot.uri] = token
+
+            def analyze() -> None:
+                with self._analysis_lock:
+                    if self._analysis_tokens.get(snapshot.uri) != token:
+                        return
+
+                try:
+                    diagnostic_state = self.diagnostic_snapshot(snapshot.uri)
+                    if (
+                        diagnostic_state is None
+                        or diagnostic_state[0] != snapshot.version
+                    ):
+                        self.compute_diagnostics(snapshot)
+                    with self._analysis_lock:
+                        if self._analysis_tokens.get(snapshot.uri) != token:
+                            return
+                    if not self.index_is_current(snapshot):
+                        self.update_poco_completion_for_file(snapshot)
+                except Exception:
+                    LOGGER.exception("Delayed analysis failed for %s", snapshot.uri)
+                finally:
+                    with self._analysis_lock:
+                        if self._analysis_tokens.get(snapshot.uri) == token:
+                            self._analysis_tokens.pop(snapshot.uri, None)
+                            self._analysis_timers.pop(snapshot.uri, None)
+
+            timer = threading.Timer(delay_seconds, analyze)
+            timer.daemon = True
+            self._analysis_timers[snapshot.uri] = timer
+            timer.start()
+
+    def analyze_document_now(self, document: TextDocument) -> None:
+        """Cancel delayed work and synchronously analyze the current document."""
+        self._cancel_document_analysis(document.uri)
+        self._invalidate_document_work(document)
+        diagnostic_state = self.diagnostic_snapshot(document.uri)
+        if diagnostic_state is None or diagnostic_state[0] != document.version:
+            self.compute_diagnostics(document)
+        if not self.index_is_current(document):
+            self.update_poco_completion_for_file(document)
+
+    def index_snapshot(self) -> tuple[dict, dict, dict]:
+        """Return stable copies for request handlers running beside the indexer."""
+        with self._index_lock:
+            return (
+                {path: list(items) for path, items in self.poco_completion.items()},
+                {
+                    path: dict(signatures)
+                    for path, signatures in self.proc_signatures.items()
+                },
+                {path: dict(docs) for path, docs in self.proc_docs.items()},
+            )
+
+    def diagnostic_snapshot(self, uri: str):
+        with self._index_lock:
+            return self.diagnostics.get(uri)
+
+    def navigation_snapshot(self) -> dict[str, FileSymbolIndex]:
+        """Return an immutable snapshot of the workspace symbol indexes."""
+        with self._index_lock:
+            return dict(self.navigation_indexes)
+
+    def _begin_index_update(self, filepath: str, version: int | None) -> int | None:
+        with self._index_lock:
+            indexed_version = self._index_versions.get(filepath)
+            if version is None and indexed_version is not None:
+                return None
+            if (
+                version is not None
+                and indexed_version is not None
+                and version < indexed_version
+            ):
+                return None
+
+            self._next_index_token += 1
+            token = self._next_index_token
+            self._index_tokens[filepath] = token
+            self._index_versions[filepath] = version
+            return token
+
+    def _discard_index_update(self, filepath: str, token: int) -> None:
+        with self._index_lock:
+            if self._index_tokens.get(filepath) != token:
+                return
+            self.poco_completion.pop(filepath, None)
+            self.proc_signatures.pop(filepath, None)
+            self.proc_docs.pop(filepath, None)
+            self.navigation_indexes.pop(filepath, None)
+            self.variable_indexes.pop(filepath, None)
+            self._committed_index_versions.pop(filepath, None)
+            self._invalidate_workspace_caches_locked()
+
+    def indexed_paths_under_uri(self, uri: str) -> list[pathlib.Path]:
+        target = pathlib.Path(uris.to_fs_path(uri))
+        with self._index_lock:
+            indexed_paths = set(self.poco_completion)
+            indexed_paths.update(self.proc_signatures)
+            indexed_paths.update(self.proc_docs)
+            indexed_paths.update(self.navigation_indexes)
+            indexed_paths.update(self.variable_indexes)
+            indexed_paths.update(self._index_tokens)
+        return [
+            pathlib.Path(path)
+            for path in indexed_paths
+            if self._is_same_or_child(path, target)
+        ]
+
+    def remove_file_state(self, uri: str) -> None:
+        """Remove cached and indexed state for a file or a complete folder."""
+        self.cancel_analysis_under_uri(uri)
+        target = pathlib.Path(uris.to_fs_path(uri))
+
+        with self._index_lock:
+            index_changed = False
+            for store in (
+                self.poco_completion,
+                self.proc_signatures,
+                self.proc_docs,
+                self.navigation_indexes,
+                self.variable_indexes,
+                self._index_tokens,
+                self._index_versions,
+                self._committed_index_versions,
+            ):
+                for path in list(store):
+                    if self._is_same_or_child(path, target):
+                        del store[path]
+                        index_changed = True
+
+            if index_changed:
+                self._invalidate_workspace_caches_locked()
+
+            diagnostic_uris = set(self.diagnostics)
+            diagnostic_uris.update(self._diagnostic_tokens)
+            for diagnostic_uri in diagnostic_uris:
+                try:
+                    diagnostic_path = pathlib.Path(uris.to_fs_path(diagnostic_uri))
+                except (TypeError, ValueError):
+                    continue
+                if self._is_same_or_child(diagnostic_path, target):
+                    self.diagnostics.pop(diagnostic_uri, None)
+                    self._diagnostic_tokens.pop(diagnostic_uri, None)
+
+        with self._parser_lock:
+            cached_keys = set(self._ast_cache)
+            cached_keys.update(self._line_cache)
+            for key in cached_keys:
+                try:
+                    cached_path = pathlib.Path(uris.to_fs_path(key[0]))
+                except (TypeError, ValueError):
+                    continue
+                if self._is_same_or_child(cached_path, target):
+                    self._ast_cache.pop(key, None)
+                    self._line_cache.pop(key, None)
+
+    def update_poco_completion_for_file(
+        self,
+        document: TextDocument,
+        *,
+        cache_tree: bool = True,
+        require_file_exists: bool = False,
+    ):
         """Update poco_completion for a specific file when it changes"""
         filepath = str(pathlib.Path(uris.to_fs_path(document.uri)))
+        token = self._begin_index_update(filepath, document.version)
+        if token is None:
+            return False
 
-        # Remove existing completion items for this file
+        collector = CompletionCollector()
-        if filepath in self.poco_completion:
-            del self.poco_completion[filepath]
-        if filepath in self.proc_signatures:
-            del self.proc_signatures[filepath]
-        if filepath in self.proc_docs:
-            del self.proc_docs[filepath]
-
-        # Parse and extract new completion items
-        completion.reset()
         try:
-            tree = self.get_tree(document)
+            tree = (
-            tree.accept(completion, recurse=True)
+                self.get_tree(document)
-            remove_existing_items(completion.custom_functions, self.poco_completion)
+                if cache_tree
-            self.poco_completion[filepath] = completion.custom_functions
+                else self.parse_source(document.source)
-            remove_shared_keys(self.proc_signatures, completion.proc_signatures)
+            )
-            self.proc_signatures[filepath] = completion.proc_signatures
+            tree.accept(collector, recurse=True)
-            self.proc_docs[filepath] = build_proc_docs(tree, document.source)
+            docs = build_proc_docs(tree, document.source)
+            navigation_index = build_file_symbol_index(
+                filepath, document.uri, tree
+            )
+            variable_index = build_variable_index(document.source, tree)
         except Exception as e:
-            logging.debug(f"Error parsing {filepath}: {e}")
+            LOGGER.debug("Error parsing %s: %s", filepath, e)
+            self._discard_index_update(filepath, token)
+            return False
+
+        if require_file_exists and not pathlib.Path(filepath).is_file():
+            self._discard_index_update(filepath, token)
+            return False
+
+        with self._index_lock:
+            if self._index_tokens.get(filepath) != token:
+                return False
+            self.poco_completion[filepath] = list(collector.custom_functions)
+            self.proc_signatures[filepath] = dict(collector.proc_signatures)
+            self.proc_docs[filepath] = docs
+            self.navigation_indexes[filepath] = navigation_index
+            self.variable_indexes[filepath] = (document.version, variable_index)
+            self._committed_index_versions[filepath] = document.version
+            self._invalidate_workspace_caches_locked()
+        return True
 
     def format(
         self,
@@ -107,6 +581,7 @@ class TclLanguageServer(server.LanguageServer):
             ),
         )
 
+        with self._parser_lock:
             if range is not None:
                 start, end = range
                 return formatter.format_partial(document.source[start:end], self.parser)
@@ -117,7 +592,8 @@ class TclLanguageServer(server.LanguageServer):
         self,
         document: TextDocument,
     ) -> List[Violation]:
-        tree, violations = self.get_tree_and_violations(document)
+        tree, cached_violations = self.get_tree_and_violations(document)
+        violations = list(cached_violations)
         for checker in checks.get_checkers():
             violations += checker.check(document.source, tree)
         return violations
@@ -144,8 +620,12 @@ class TclLanguageServer(server.LanguageServer):
         for violation in violations:
             message = violation.message
             severity = lsp.DiagnosticSeverity.Warning
-            start = lsp.Position(line=violation.start[0] - 1, character=violation.start[1] - 1)
+            start = lsp.Position(
-            end = lsp.Position(line=violation.end[0] - 1, character=violation.end[1] - 1)
+                line=violation.start[0] - 1, character=violation.start[1] - 1
+            )
+            end = lsp.Position(
+                line=violation.end[0] - 1, character=violation.end[1] - 1
+            )
 
             diagnostics.append(
                 lsp.Diagnostic(
@@ -166,12 +646,27 @@ class TclLanguageServer(server.LanguageServer):
         return self.lint(document)
 
     def compute_diagnostics(self, document: TextDocument):
-        # `None` sentinel ensures that `diagnostics` gets updated if the URI is not
+        with self._index_lock:
-        # present.
+            self._next_diagnostic_token += 1
-        _, previous = self.diagnostics.get(document, (0, None))
+            token = self._next_diagnostic_token
+            self._diagnostic_tokens[document.uri] = token
 
         diagnostics = self._compute_diagnostics(document)
 
-        # Only update if the list has changed
+        with self._index_lock:
-        if previous != diagnostics:
+            if self._diagnostic_tokens.get(document.uri) != token:
+                return
+
+            current = self.diagnostics.get(document.uri)
+            if current is not None:
+                current_version, _ = current
+                if (
+                    current_version is not None
+                    and document.version is not None
+                    and current_version > document.version
+                ):
+                    return
+
+            # Keep the result id in sync even when only the document version changed.
+            if current != (document.version, diagnostics):
                 self.diagnostics[document.uri] = (document.version, diagnostics)

server/src/tools/completion_items.py

@@ -1,8 +1,9 @@
-from tclint.syntax_tree import Visitor, Command, BareWord, List
 import lsprotocol.types as lsp
 from common.load_data import standard_items
+from tclint.syntax_tree import BareWord, Command, List, Visitor
 
 BUILTIN_VAR_LABELS = {ci.label for ci in standard_items.nx_variables}
+BUILTIN_PROC_LABELS = {ci.label for ci in standard_items.nx_procs}
 
 
 class CompletionItems:
@@ -18,10 +19,11 @@ class CompletionItems:
         self._custom_functions.append(value)
 
 
-class _Completion(Visitor):
+class CompletionCollector(Visitor):
     def __init__(self):
         super().__init__()
         self._custom_functions: list[lsp.CompletionItem] = []
+        self._custom_function_keys: set[tuple[str, lsp.CompletionItemKind | None]] = set()
         self._proc_signatures = {}
 
     @property
@@ -32,13 +34,12 @@ class _Completion(Visitor):
     def proc_signatures(self):
         return self._proc_signatures
 
-    def reset(self):
-        self._custom_functions = []
-        self._proc_signatures = {}
-
     def _append_unique(self, item: lsp.CompletionItem):
         # Avoid duplicate labels within the same file scan
-        if not any(ci.label == item.label for ci in self._custom_functions):
+        key = (item.label, item.kind)
+        if key in self._custom_function_keys:
+            return
+        self._custom_function_keys.add(key)
         self._custom_functions.append(item)
 
     def visit_command(self, command: Command):
@@ -50,7 +51,7 @@ class _Completion(Visitor):
             if not getattr(first_arg, "value", None):
                 return
 
-            if any(item.label == first_arg.value for item in standard_items.nx_procs):
+            if first_arg.value in BUILTIN_PROC_LABELS:
                 return
 
             # Record proc name as a completion item
@@ -90,35 +91,3 @@ class _Completion(Visitor):
                     clean_name = base_name[2:]  # remove leading '::' for completion display
                     if clean_name not in BUILTIN_VAR_LABELS:
                         self._append_unique(lsp.CompletionItem(label=clean_name, kind=lsp.CompletionItemKind.Variable))
-
-
-def remove_existing_items(items: list[lsp.CompletionItem], store: dict) -> None:
-    """
-    Entfernt alle CompletionItems aus dem store, deren label in der items-Liste vorkommt.
-    Änderungen erfolgen in-place.
-    """
-    labels_to_remove = {item.label for item in items}
-
-    for key in list(store.keys()):
-        filtered = [ci for ci in store[key] if ci.label not in labels_to_remove]
-        if filtered:
-            store[key] = filtered
-        else:
-            del store[key]
-
-
-def remove_shared_keys(nested_dict: dict[str, dict[str, list]], flat_dict: dict[str, list]) -> None:
-    """
-    Entfernt alle Keys aus nested_dict[file][func], wenn func auch in flat_dict vorhanden ist.
-    Änderungen erfolgen in-place.
-    """
-    for file_path, func_dict in list(nested_dict.items()):
-        for func_name in list(func_dict.keys()):
-            if func_name in flat_dict:
-                del nested_dict[file_path][func_name]
-
-        if not nested_dict[file_path]:
-            del nested_dict[file_path]
-
-
-completion = _Completion()

server/src/tools/inlay_hint.py

@@ -1,29 +1,265 @@
+from __future__ import annotations
+
+import os
+import re
+from collections.abc import Mapping, Sequence
+from dataclasses import dataclass
+from typing import Any
+
 import lsprotocol.types as lsp
-from tclint.syntax_tree import Visitor, Command
+from tclint.syntax_tree import Command, VarSub, Visitor
+from tools.navigation import FileSymbolIndex
+
+
+@dataclass(frozen=True)
+class InlayHintParameter:
+    name: str
+    documentation: str | None = None
+    variadic: bool = False
+
+
+@dataclass(frozen=True)
+class InlayHintSignature:
+    parameters: tuple[InlayHintParameter, ...]
+    display_label: str
+    documentation: str | None = None
+    location: lsp.Location | None = None
+
+
+def _normalized_path(path: str) -> str:
+    return os.path.normcase(os.path.abspath(path))
+
+
+def _definition_locations(
+    index: FileSymbolIndex | None,
+) -> dict[str, lsp.Location]:
+    if index is None:
+        return {}
+
+    locations = {}
+    for occurrence in index.occurrences:
+        if (
+            occurrence.is_definition
+            and occurrence.identity.kind == "proc"
+        ):
+            locations[occurrence.placeholder] = lsp.Location(
+                uri=index.uri, range=occurrence.range
+            )
+    return locations
+
+
+def build_custom_inlay_signatures(
+    signatures_by_path: dict[str, dict[str, list[str]]],
+    docs_by_path: dict[str, dict[str, str]],
+    indexes_by_path: dict[str, FileSymbolIndex],
+    current_path: str,
+) -> dict[str, InlayHintSignature]:
+    """Merge workspace signatures deterministically, preferring the current file."""
+    current_normalized = _normalized_path(current_path)
+    paths = sorted(
+        signatures_by_path, key=lambda path: _normalized_path(path).casefold()
+    )
+    paths.sort(key=lambda path: _normalized_path(path) == current_normalized)
+
+    result: dict[str, InlayHintSignature] = {}
+    for path in paths:
+        docs = docs_by_path.get(path, {})
+        definition_locations = _definition_locations(indexes_by_path.get(path))
+        for proc_name, parameter_names in signatures_by_path[path].items():
+            parameters = tuple(
+                InlayHintParameter(
+                    name=parameter_name,
+                    variadic=(
+                        parameter_name == "args"
+                        and parameter_index == len(parameter_names) - 1
+                    ),
+                )
+                for parameter_index, parameter_name in enumerate(parameter_names)
+            )
+            result[proc_name] = InlayHintSignature(
+                parameters=parameters,
+                display_label=" ".join([proc_name, *parameter_names]),
+                documentation=docs.get(proc_name),
+                location=definition_locations.get(
+                    proc_name.removeprefix("::").rsplit("::", 1)[-1]
+                ),
+            )
+    return result
+
+
+def _is_builtin_variadic(item: dict[str, Any], parameter_name: str, index: int) -> bool:
+    parameters = item.get("parameters", [])
+    if index != len(parameters) - 1:
+        return False
+    if "..." in parameter_name or "…" in parameter_name:
+        return True
+
+    format_label = item.get("format", "")
+    return (
+        f"<{parameter_name}>+" in format_label or f"[{parameter_name}]+" in format_label
+    )
+
+
+def _builtin_parameter_label(parameter_name: str) -> str:
+    if "..." not in parameter_name and "…" not in parameter_name:
+        return parameter_name.strip("<>[]")
+
+    first_name = parameter_name.split()[0].strip("<>[]")
+    return re.sub(r"(?:_?1)$", "", first_name) or first_name
+
+
+def build_builtin_inlay_signatures(
+    items: list[dict[str, Any]],
+) -> dict[str, InlayHintSignature]:
+    result = {}
+    for item in items:
+        proc_name = item.get("label")
+        if not proc_name:
+            continue
+        parameters = tuple(
+            InlayHintParameter(
+                name=_builtin_parameter_label(parameter.get("name", "")),
+                documentation=parameter.get("desc") or None,
+                variadic=_is_builtin_variadic(
+                    item, parameter.get("name", ""), parameter_index
+                ),
+            )
+            for parameter_index, parameter in enumerate(item.get("parameters", []))
+            if parameter.get("name")
+        )
+        result[proc_name] = InlayHintSignature(
+            parameters=parameters,
+            display_label=item.get("format") or proc_name,
+            documentation=item.get("description") or None,
+        )
+    return result
+
+
+def _position_in_range(
+    position: lsp.Position, requested_range: lsp.Range | None
+) -> bool:
+    if requested_range is None:
+        return True
+    value = (position.line, position.character)
+    start = (requested_range.start.line, requested_range.start.character)
+    end = (requested_range.end.line, requested_range.end.character)
+    return start <= value < end
 
 
 class InlayHintGenerator(Visitor):
-    def __init__(self, proc_signatures):
+    def __init__(
+        self,
+        source: str,
+        proc_signatures: Mapping[str, InlayHintSignature],
+        *,
+        source_lines: Sequence[str] | None = None,
+        requested_range: lsp.Range | None = None,
+        parameter_names: str = "all",
+        suppress_when_argument_matches_name: bool = True,
+    ):
+        self.source_lines = (
+            source_lines if source_lines is not None else source.splitlines()
+        )
         self.proc_signatures = proc_signatures
-        self.hints = []
+        self.requested_range = requested_range
+        self.parameter_names = parameter_names
+        self.suppress_when_argument_matches_name = suppress_when_argument_matches_name
+        self.hints: list[lsp.InlayHint] = []
+
+    def _node_intersects_requested_range(self, node) -> bool:
+        if self.requested_range is None:
+            return True
+        start = getattr(node, "pos", None)
+        end = getattr(node, "end_pos", None)
+        if start is None or end is None:
+            return True
+
+        node_start_line = start[0] - 1
+        node_end_line = end[0] - 1
+        return not (
+            node_end_line < self.requested_range.start.line
+            or node_start_line > self.requested_range.end.line
+        )
+
+    def generate(self, tree) -> list[lsp.InlayHint]:
+        """Walk only syntax-tree branches overlapping the requested editor range."""
+        self.hints.clear()
+
+        def walk(node) -> None:
+            if not self._node_intersects_requested_range(node):
+                return
+            if isinstance(node, Command):
+                self.visit_command(node)
+            for child in getattr(node, "children", []):
+                walk(child)
+
+        walk(tree)
+        return self.hints
+
+    def _position(self, line: int, column: int) -> lsp.Position:
+        line_index = line - 1
+        character_index = column - 1
+        if 0 <= line_index < len(self.source_lines):
+            prefix = self.source_lines[line_index][:character_index]
+            character_index = len(prefix.encode("utf-16-le")) // 2
+        return lsp.Position(line=line_index, character=character_index)
+
+    @staticmethod
+    def _parameter_for_argument(
+        signature: InlayHintSignature, argument_index: int
+    ) -> InlayHintParameter | None:
+        if argument_index < len(signature.parameters):
+            return signature.parameters[argument_index]
+        if signature.parameters and signature.parameters[-1].variadic:
+            return signature.parameters[-1]
+        return None
+
+    def _should_show(self, argument, parameter: InlayHintParameter) -> bool:
+        if self.parameter_names == "none":
+            return False
+        if self.parameter_names == "literals" and isinstance(argument, VarSub):
+            return False
+        if not self.suppress_when_argument_matches_name or not isinstance(
+            argument, VarSub
+        ):
+            return True
+        return getattr(argument, "value", None) != parameter.name
+
+    @staticmethod
+    def _tooltip(signature: InlayHintSignature) -> lsp.MarkupContent:
+        value = f"`{signature.display_label}`"
+        if signature.documentation:
+            value += f"\n\n{signature.documentation}"
+        return lsp.MarkupContent(kind=lsp.MarkupKind.Markdown, value=value)
 
     def visit_command(self, command: Command):
         name = getattr(command.routine, "contents", None)
-        if name not in self.proc_signatures:
+        signature = self.proc_signatures.get(name)
+        if signature is None or self.parameter_names == "none":
             return
 
-        param_names = self.proc_signatures[name]
+        for argument_index, argument in enumerate(command.args):
-        for idx, arg in enumerate(command.args):
+            parameter = self._parameter_for_argument(signature, argument_index)
-            if idx >= len(param_names):
+            if parameter is None:
                 break
-            param_name = param_names[idx]
+            if not argument.pos or not self._should_show(argument, parameter):
+                continue
 
-            if arg.pos:
+            line, column = argument.pos
-                line, col = arg.pos
+            position = self._position(line, column)
+            if not _position_in_range(position, self.requested_range):
+                continue
+
+            label = lsp.InlayHintLabelPart(
+                value=f"{parameter.name}:",
+                tooltip=parameter.documentation,
+                location=signature.location,
+            )
             self.hints.append(
                 lsp.InlayHint(
-                        position=lsp.Position(line=line - 1, character=col - 1),
+                    position=position,
-                        label=f"{param_name}:",
+                    label=[label],
                     kind=lsp.InlayHintKind.Parameter,
+                    tooltip=self._tooltip(signature),
                 )
             )

server/src/tools/navigation.py

@@ -0,0 +1,519 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+import lsprotocol.types as lsp
+from tclint.syntax_tree import BareWord, Command, List, Node, Script, VarSub
+
+
+ROOT_NAMESPACE = "::"
+
+
+@dataclass(frozen=True)
+class SymbolIdentity:
+    kind: str
+    name: str
+    scope: str | None = None
+
+
+@dataclass(frozen=True)
+class SymbolOccurrence:
+    identity: SymbolIdentity
+    range: lsp.Range
+    placeholder: str
+    is_definition: bool = False
+    symbol_kind: lsp.SymbolKind = lsp.SymbolKind.Variable
+    container_name: str | None = None
+    fallback_identity: SymbolIdentity | None = None
+
+
+@dataclass(frozen=True)
+class FileSymbolIndex:
+    path: str
+    uri: str
+    occurrences: tuple[SymbolOccurrence, ...]
+
+
+@dataclass(frozen=True)
+class _Scope:
+    filepath: str
+    namespace: str = ROOT_NAMESPACE
+    proc_name: str | None = None
+    global_variables: tuple[tuple[str, str], ...] = ()
+    namespace_variables: tuple[tuple[str, str], ...] = ()
+
+
+def _without_array_index(name: str) -> str:
+    return name.split("(", 1)[0]
+
+
+def _basename(name: str) -> str:
+    return _without_array_index(name).rsplit("::", 1)[-1]
+
+
+def _qualify(name: str, namespace: str) -> str:
+    name = _without_array_index(name)
+    if name.startswith("::"):
+        return name
+    if namespace == ROOT_NAMESPACE:
+        return f"::{name}"
+    return f"{namespace}::{name}"
+
+
+def _namespace_of(qualified_name: str) -> str:
+    parent = qualified_name.rsplit("::", 1)[0]
+    return parent or ROOT_NAMESPACE
+
+
+def _display_name(identity: SymbolIdentity) -> str:
+    if identity.kind == "variable" and identity.scope is not None:
+        return identity.name
+    return identity.name.removeprefix("::")
+
+
+def _container_name(identity: SymbolIdentity) -> str | None:
+    if identity.scope is not None:
+        _, _, proc_name = identity.scope.partition("::proc::")
+        return proc_name.removeprefix("::") or None
+
+    qualified = identity.name.removeprefix("::")
+    if "::" not in qualified:
+        return None
+    return qualified.rsplit("::", 1)[0]
+
+
+def _static_contents(node: Node | None) -> str | None:
+    value = getattr(node, "contents", None)
+    return value if isinstance(value, str) else None
+
+
+def _name_range(node: Node, raw_name: str, *, variable_sub: bool = False) -> lsp.Range:
+    if variable_sub:
+        line, column = node.pos
+        column += 2 if getattr(node, "braced", False) else 1
+    else:
+        position = getattr(node, "contents_pos", None) or node.pos
+        line, column = position
+
+    normalized = _without_array_index(raw_name)
+    prefix_length = normalized.rfind("::") + 2 if "::" in normalized else 0
+    start_character = column - 1 + prefix_length
+    name = normalized[prefix_length:]
+    return lsp.Range(
+        start=lsp.Position(line=line - 1, character=start_character),
+        end=lsp.Position(line=line - 1, character=start_character + len(name)),
+    )
+
+
+def _proc_identity(raw_name: str, namespace: str) -> SymbolIdentity:
+    return SymbolIdentity(kind="proc", name=_qualify(raw_name, namespace))
+
+
+def _proc_fallback(raw_name: str, namespace: str) -> SymbolIdentity | None:
+    if raw_name.startswith("::") or "::" in raw_name or namespace == ROOT_NAMESPACE:
+        return None
+    return SymbolIdentity(kind="proc", name=_qualify(raw_name, ROOT_NAMESPACE))
+
+
+def _variable_identity(raw_name: str, scope: _Scope) -> SymbolIdentity:
+    normalized = _without_array_index(raw_name)
+    if normalized.startswith("::"):
+        return SymbolIdentity(kind="variable", name=normalized)
+
+    if "::" in normalized:
+        return SymbolIdentity(
+            kind="variable", name=_qualify(normalized, scope.namespace)
+        )
+
+    if scope.proc_name is None:
+        return SymbolIdentity(
+            kind="variable", name=_qualify(normalized, scope.namespace)
+        )
+
+    for alias, target in scope.global_variables + scope.namespace_variables:
+        if normalized == alias:
+            return SymbolIdentity(kind="variable", name=target)
+
+    return SymbolIdentity(
+        kind="variable",
+        name=normalized,
+        scope=f"{scope.filepath}::proc::{scope.proc_name}",
+    )
+
+
+def _variable_command_nodes(command: Command) -> list[tuple[Node, bool]]:
+    routine = _static_contents(command.routine)
+    if routine == "set" and command.args:
+        return [(command.args[0], len(command.args) >= 2)]
+    if routine in {"incr", "append", "lappend"} and command.args:
+        return [(command.args[0], True)]
+    if routine == "lset" and command.args:
+        return [(command.args[0], False)]
+    if routine == "unset":
+        return [
+            (argument, False)
+            for argument in command.args
+            if not (_static_contents(argument) or "").startswith("-")
+        ]
+    if routine == "array" and len(command.args) >= 2:
+        return [
+            (command.args[1], _static_contents(command.args[0]) == "set")
+        ]
+    if routine == "dict" and len(command.args) >= 2:
+        subcommand = _static_contents(command.args[0])
+        if subcommand in {"set", "unset", "append", "incr", "lappend", "update", "with"}:
+            return [
+                (
+                    command.args[1],
+                    subcommand in {"set", "append", "incr", "lappend"},
+                )
+            ]
+    return []
+
+
+def _binding_nodes(node: Node) -> list[Node]:
+    if isinstance(node, List):
+        return list(node.children)
+    return [node]
+
+
+def _variable_binding_nodes(command: Command) -> list[Node]:
+    routine = _static_contents(command.routine)
+    if routine in {"foreach", "lmap"} and len(command.args) >= 3:
+        return [
+            variable
+            for variable_list in command.args[:-1:2]
+            for variable in _binding_nodes(variable_list)
+        ]
+    if routine == "lassign" and len(command.args) >= 2:
+        return list(command.args[1:])
+    if routine == "catch" and len(command.args) >= 2:
+        return list(command.args[1:3])
+    if (
+        routine == "dict"
+        and command.args
+        and _static_contents(command.args[0]) == "update"
+    ):
+        return list(command.args[3:-1:2])
+    return []
+
+
+def _variable_declaration_nodes(command: Command) -> list[Node]:
+    routine = _static_contents(command.routine)
+    if routine == "global":
+        return list(command.args)
+    if routine == "variable":
+        return list(command.args[::2])
+    return []
+
+
+def _scan_proc_imports(
+    node: Node, namespace: str
+) -> tuple[dict[str, str], dict[str, str]]:
+    global_variables: dict[str, str] = {}
+    namespace_variables: dict[str, str] = {}
+
+    def walk(current: Node) -> None:
+        if isinstance(current, Command):
+            routine = _static_contents(current.routine)
+            if routine == "proc":
+                return
+            if routine == "global":
+                for argument in current.args:
+                    name = _static_contents(argument)
+                    if name:
+                        global_variables[_basename(name)] = _qualify(
+                            name, ROOT_NAMESPACE
+                        )
+            elif routine == "variable":
+                for argument in current.args[::2]:
+                    name = _static_contents(argument)
+                    if name:
+                        namespace_variables[_basename(name)] = _qualify(
+                            name, namespace
+                        )
+
+        for child in getattr(current, "children", []):
+            walk(child)
+
+    walk(node)
+    return global_variables, namespace_variables
+
+
+def build_file_symbol_index(
+    filepath: str, uri: str, tree: Node
+) -> FileSymbolIndex:
+    occurrences: list[SymbolOccurrence] = []
+
+    def add_proc(
+        node: Node,
+        raw_name: str,
+        scope: _Scope,
+        *,
+        is_definition: bool,
+    ) -> None:
+        identity = _proc_identity(raw_name, scope.namespace)
+        occurrences.append(
+            SymbolOccurrence(
+                identity=identity,
+                fallback_identity=(
+                    None
+                    if is_definition
+                    else _proc_fallback(raw_name, scope.namespace)
+                ),
+                range=_name_range(node, raw_name),
+                placeholder=_basename(raw_name),
+                is_definition=is_definition,
+                symbol_kind=lsp.SymbolKind.Function,
+                container_name=_container_name(identity),
+            )
+        )
+
+    def add_variable(
+        node: Node,
+        raw_name: str,
+        scope: _Scope,
+        *,
+        is_definition: bool,
+        variable_sub: bool = False,
+        identity: SymbolIdentity | None = None,
+    ) -> None:
+        symbol_identity = identity or _variable_identity(raw_name, scope)
+        occurrences.append(
+            SymbolOccurrence(
+                identity=symbol_identity,
+                range=_name_range(node, raw_name, variable_sub=variable_sub),
+                placeholder=_basename(raw_name),
+                is_definition=is_definition,
+                symbol_kind=lsp.SymbolKind.Variable,
+                container_name=_container_name(symbol_identity),
+            )
+        )
+
+    def walk_embedded(node: Node, scope: _Scope) -> None:
+        if isinstance(node, Script):
+            walk_script(node, scope)
+            return
+        if isinstance(node, Command):
+            walk_command(node, scope)
+            return
+        if isinstance(node, VarSub):
+            raw_name = getattr(node, "value", None)
+            if isinstance(raw_name, str):
+                add_variable(
+                    node,
+                    raw_name,
+                    scope,
+                    is_definition=False,
+                    variable_sub=True,
+                )
+
+        for child in getattr(node, "children", []):
+            walk_embedded(child, scope)
+
+    def walk_proc(command: Command, scope: _Scope) -> None:
+        if len(command.args) < 3:
+            return
+        raw_name = _static_contents(command.args[0])
+        body = command.args[2]
+        if raw_name is None or not isinstance(body, Script):
+            return
+
+        add_proc(command.args[0], raw_name, scope, is_definition=True)
+        proc_identity = _proc_identity(raw_name, scope.namespace)
+        proc_namespace = _namespace_of(proc_identity.name)
+        global_variables, namespace_variables = _scan_proc_imports(
+            body, proc_namespace
+        )
+        proc_scope = _Scope(
+            filepath=filepath,
+            namespace=proc_namespace,
+            proc_name=proc_identity.name,
+            global_variables=tuple(sorted(global_variables.items())),
+            namespace_variables=tuple(sorted(namespace_variables.items())),
+        )
+
+        parameters = command.args[1]
+        for parameter in getattr(parameters, "children", []):
+            parameter_node = parameter
+            if isinstance(parameter, List) and parameter.children:
+                parameter_node = parameter.children[0]
+            parameter_name = _static_contents(parameter_node)
+            if parameter_name:
+                add_variable(
+                    parameter_node,
+                    parameter_name,
+                    proc_scope,
+                    is_definition=True,
+                )
+
+        walk_script(body, proc_scope)
+
+    def walk_namespace(command: Command, scope: _Scope) -> bool:
+        if len(command.args) < 3 or _static_contents(command.args[0]) != "eval":
+            return False
+        raw_name = _static_contents(command.args[1])
+        body = command.args[2]
+        if raw_name is None or not isinstance(body, Script):
+            return False
+
+        namespace = _qualify(raw_name, scope.namespace)
+        identity = SymbolIdentity(kind="namespace", name=namespace)
+        occurrences.append(
+            SymbolOccurrence(
+                identity=identity,
+                range=_name_range(command.args[1], raw_name),
+                placeholder=_basename(raw_name),
+                is_definition=True,
+                symbol_kind=lsp.SymbolKind.Namespace,
+                container_name=_container_name(identity),
+            )
+        )
+        walk_script(
+            body,
+            _Scope(filepath=filepath, namespace=namespace),
+        )
+        return True
+
+    def walk_command(command: Command, scope: _Scope) -> None:
+        routine = _static_contents(command.routine)
+        if routine == "proc":
+            walk_proc(command, scope)
+            return
+        if routine == "namespace" and walk_namespace(command, scope):
+            return
+
+        if routine:
+            add_proc(command.routine, routine, scope, is_definition=False)
+
+        declaration_nodes = _variable_declaration_nodes(command)
+        declaration_ids = {id(node) for node in declaration_nodes}
+        for node in declaration_nodes:
+            raw_name = _static_contents(node)
+            if raw_name:
+                is_definition = routine == "variable" and scope.proc_name is None
+                if routine == "global":
+                    identity = SymbolIdentity(
+                        kind="variable",
+                        name=_qualify(raw_name, ROOT_NAMESPACE),
+                    )
+                else:
+                    identity = SymbolIdentity(
+                        kind="variable",
+                        name=_qualify(raw_name, scope.namespace),
+                    )
+                add_variable(
+                    node,
+                    raw_name,
+                    scope,
+                    is_definition=is_definition,
+                    identity=identity,
+                )
+
+        for node, is_definition in _variable_command_nodes(command):
+            if id(node) in declaration_ids:
+                continue
+            raw_name = _static_contents(node)
+            if raw_name:
+                add_variable(
+                    node,
+                    raw_name,
+                    scope,
+                    is_definition=is_definition,
+                )
+
+        for node in _variable_binding_nodes(command):
+            raw_name = _static_contents(node)
+            if raw_name:
+                add_variable(node, raw_name, scope, is_definition=True)
+
+        for argument in command.args:
+            walk_embedded(argument, scope)
+
+    def walk_script(script: Node, scope: _Scope) -> None:
+        for child in getattr(script, "children", []):
+            walk_embedded(child, scope)
+
+    walk_script(tree, _Scope(filepath=filepath))
+    return FileSymbolIndex(path=filepath, uri=uri, occurrences=tuple(occurrences))
+
+
+def definition_identities(indexes: dict[str, FileSymbolIndex]) -> set[SymbolIdentity]:
+    return {
+        occurrence.identity
+        for index in indexes.values()
+        for occurrence in index.occurrences
+        if occurrence.is_definition
+    }
+
+
+def resolve_identity(
+    occurrence: SymbolOccurrence, definitions: set[SymbolIdentity]
+) -> SymbolIdentity:
+    if occurrence.identity in definitions or occurrence.fallback_identity is None:
+        return occurrence.identity
+    if occurrence.fallback_identity in definitions:
+        return occurrence.fallback_identity
+    return occurrence.identity
+
+
+def symbol_at_position(
+    index: FileSymbolIndex,
+    position: lsp.Position,
+    definitions: set[SymbolIdentity],
+) -> tuple[SymbolOccurrence, SymbolIdentity] | None:
+    for occurrence in index.occurrences:
+        start = occurrence.range.start
+        end = occurrence.range.end
+        if (
+            position.line == start.line == end.line
+            and start.character <= position.character < end.character
+        ):
+            return occurrence, resolve_identity(occurrence, definitions)
+    return None
+
+
+def matching_occurrences(
+    identity: SymbolIdentity,
+    indexes: dict[str, FileSymbolIndex],
+    definitions: set[SymbolIdentity],
+) -> list[tuple[FileSymbolIndex, SymbolOccurrence]]:
+    matches = []
+    for index in indexes.values():
+        for occurrence in index.occurrences:
+            if resolve_identity(occurrence, definitions) == identity:
+                matches.append((index, occurrence))
+    return matches
+
+
+def workspace_symbols(
+    indexes: dict[str, FileSymbolIndex], query: str
+) -> list[lsp.SymbolInformation]:
+    query = query.casefold()
+    results = []
+    seen = set()
+    for index in indexes.values():
+        for occurrence in index.occurrences:
+            identity = occurrence.identity
+            if not occurrence.is_definition:
+                continue
+            if identity.kind == "variable" and identity.scope is not None:
+                continue
+
+            name = _display_name(identity)
+            if query and query not in name.casefold():
+                continue
+
+            key = identity
+            if key in seen:
+                continue
+            seen.add(key)
+            results.append(
+                lsp.SymbolInformation(
+                    name=name,
+                    kind=occurrence.symbol_kind,
+                    location=lsp.Location(uri=index.uri, range=occurrence.range),
+                    container_name=occurrence.container_name,
+                )
+            )
+    return sorted(results, key=lambda symbol: symbol.name.casefold())

server/src/tools/proc_docs.py

@@ -1,8 +1,9 @@
 import re
 from typing import Dict, List
 
-from tclint.syntax_tree import Visitor, Command
+from tclint.syntax_tree import Command, Visitor
-from tools.parser import CustomParser
+
+PROC_DECLARATION_RE = re.compile(r"^\s*proc\s+([^\s\{]+)")
 
 
 def _strip_comment_prefix(line: str) -> str:
@@ -135,43 +136,18 @@ def build_proc_docs(tree, source_text: str) -> Dict[str, str]:
     return extractor.docs
 
 
-def is_proc_declaration_position(source_text: str, line_zero_based: int, char_zero_based: int) -> bool:
+def is_proc_declaration_line(line: str, char_zero_based: int) -> bool:
+    """Return True if the position is on the proc name on this source line."""
+    match = PROC_DECLARATION_RE.match(line)
+    return bool(match and match.start(1) <= char_zero_based <= match.end(1))
+
+
+def is_proc_declaration_position(
+    source_text: str, line_zero_based: int, char_zero_based: int
+) -> bool:
     """Return True if the position is on a proc name within its declaration."""
-    parser = CustomParser()
-    tree = parser.parse(source_text)
-
-    # Walk commands to find 'proc' declarations and check if position intersects the name arg
-    class _DeclFinder(Visitor):
-        def __init__(self):
-            self.is_decl = False
-
-        def visit_command(self, command: Command):
-            if self.is_decl:
-                return
-            routine = getattr(command.routine, "contents", None)
-            if routine != "proc" or not command.args:
-                return
-            name_node = command.args[0]
-            if not hasattr(name_node, "pos"):
-                return
-            # Calculate range for the name token
     try:
-                start_line, start_col = name_node.pos
+        line = source_text.splitlines()[line_zero_based]
-                end_line, end_col = getattr(name_node, "end_pos", name_node.pos)
+    except IndexError:
-            except Exception:
+        return False
-                return
+    return is_proc_declaration_line(line, char_zero_based)
-            if start_line - 1 == line_zero_based:
-                length = 0
-                if hasattr(name_node, "value") and name_node.value is not None:
-                    length = len(name_node.value)
-                elif hasattr(name_node, "contents") and name_node.contents is not None:
-                    length = len(name_node.contents)
-                if length:
-                    start_c = start_col - 1
-                    end_c = start_c + length
-                    if start_c <= char_zero_based <= end_c:
-                        self.is_decl = True
-
-    finder = _DeclFinder()
-    tree.accept(finder, recurse=True)
-    return finder.is_decl

server/src/tools/semantic_tokens.py

@@ -1,17 +1,17 @@
 import enum
 from typing import List
-from tclint.syntax_tree import Visitor, QuotedWord, Command, BareWord
+
-from tclint.commands.plugins import PluginManager
 import attrs
 from common.load_data import standard_items
-import lsprotocol.types as lsp
+from tclint.commands.plugins import PluginManager
-
+from tclint.syntax_tree import BareWord, Command, QuotedWord, Visitor
 
 # Constructing a PluginManager scans entry points, and get_commands() rebuilds
 # the builtin command set on every call. Semantic tokens are requested often, so
 # cache the manager and the resolved commands per plugin set.
 _PLUGIN_MANAGER = None
 _COMMANDS_CACHE = {}
+_STANDARD_PROC_NAMES = frozenset(item.label for item in standard_items.nx_procs)
 
 
 def _load_commands(plugins):
@@ -60,13 +60,23 @@ TOKEN_TYPES = [
     "string",
     "parameter",
 ]
+TOKEN_TYPE_INDEX = {}
+for _token_index, _token_name in enumerate(TOKEN_TYPES):
+    TOKEN_TYPE_INDEX.setdefault(_token_name, _token_index)
 
 
 class _Highlighter(Visitor):
-    def __init__(self, plugins, custom_functions: dict[str : list[lsp.CompletionItem]]):
+    def __init__(self, plugins, custom_functions):
         self._commands = _load_commands(plugins)
         self._tokens = []
-        self.custom_functions = custom_functions
+        if isinstance(custom_functions, dict):
+            self._custom_function_names = frozenset(
+                item.label
+                for items in custom_functions.values()
+                for item in items
+            )
+        else:
+            self._custom_function_names = frozenset(custom_functions)
 
     def _append_token(self, position, length: int, tok_type: str, modifiers: List[TokenModifier] | None = None):
         if position is None or length <= 0:
@@ -129,9 +139,7 @@ class _Highlighter(Visitor):
         # Highlight functions (custom or standard) when used as the routine
         name = getattr(routine, "contents", None)
         if name:
-            in_custom = any(item.label == name for items in self.custom_functions.values() for item in items)
+            if name in self._custom_function_names or name in _STANDARD_PROC_NAMES:
-            in_standard = any(item.label == name for item in standard_items.nx_procs)
-            if in_custom or in_standard:
                 line, col = routine.contents_pos
                 self._append_token((line - 1, col - 1), len(name), "function", [])
 

server/src/tools/signature_help.py

@@ -0,0 +1,173 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Any
+
+import lsprotocol.types as lsp
+from tclint.syntax_tree import Command, Node
+
+
+@dataclass(frozen=True)
+class ActiveCall:
+    name: str
+    active_argument: int
+
+
+def _to_lsp_position(position: tuple[int, int] | None) -> tuple[int, int] | None:
+    if position is None:
+        return None
+    return position[0] - 1, position[1] - 1
+
+
+def _contains_cursor(
+    command: Command, source_lines: list[str], cursor: tuple[int, int]
+) -> bool:
+    start = _to_lsp_position(getattr(command, "pos", None))
+    end = _to_lsp_position(getattr(command, "end_pos", None))
+    if start is None or end is None or cursor < start:
+        return False
+
+    if cursor <= end:
+        return True
+
+    # tclint excludes trailing whitespace from a command's range. Keep the
+    # command active while the cursor is in that whitespace so typing a space
+    # after the command name or an argument can trigger signature help.
+    if cursor[0] != end[0] or cursor[0] >= len(source_lines):
+        return False
+
+    line = source_lines[cursor[0]]
+    if cursor[1] > len(line):
+        return False
+
+    return line[end[1] : cursor[1]].isspace()
+
+
+def _active_argument(command: Command, cursor: tuple[int, int]) -> int:
+    for index, argument in enumerate(command.args):
+        start = _to_lsp_position(getattr(argument, "pos", None))
+        end = _to_lsp_position(getattr(argument, "end_pos", None))
+        if start is None or end is None:
+            continue
+        if cursor < start or start <= cursor <= end:
+            return index
+
+    return len(command.args)
+
+
+def find_active_call(
+    source: str, tree: Node, position: lsp.Position
+) -> ActiveCall | None:
+    """Return the innermost Tcl command at the cursor and its argument index."""
+    cursor = (position.line, position.character)
+    source_lines = source.split("\n")
+    candidates: list[tuple[int, tuple[int, int], Command]] = []
+
+    def walk(node: Node, depth: int = 0) -> None:
+        if isinstance(node, Command) and _contains_cursor(node, source_lines, cursor):
+            start = _to_lsp_position(getattr(node, "pos", None)) or (0, 0)
+            candidates.append((depth, start, node))
+
+        for child in getattr(node, "children", []):
+            walk(child, depth + 1)
+
+    walk(tree)
+    if not candidates:
+        return None
+
+    _, _, command = max(candidates, key=lambda item: (item[0], item[1]))
+    name = getattr(command.routine, "contents", None)
+    if not name:
+        return None
+
+    return ActiveCall(name=name, active_argument=_active_argument(command, cursor))
+
+
+def _parameter_label(
+    signature_label: str, name: str, start_at: int = 0
+) -> str | tuple[int, int]:
+    start = signature_label.find(name, start_at)
+    if start < 0:
+        start = signature_label.lower().find(name.lower(), start_at)
+    if start < 0:
+        return name
+    return start, start + len(name)
+
+
+def _custom_signature(
+    name: str, parameter_names: list[str], documentation: str | None
+) -> lsp.SignatureInformation:
+    label = " ".join([name, *parameter_names])
+    parameters = []
+    search_from = len(name)
+    for parameter_name in parameter_names:
+        parameter_label = _parameter_label(label, parameter_name, search_from)
+        parameters.append(lsp.ParameterInformation(label=parameter_label))
+        if isinstance(parameter_label, tuple):
+            search_from = parameter_label[1]
+    return lsp.SignatureInformation(
+        label=label,
+        documentation=(
+            lsp.MarkupContent(kind=lsp.MarkupKind.Markdown, value=documentation)
+            if documentation
+            else None
+        ),
+        parameters=parameters,
+    )
+
+
+def _builtin_signature(item: dict[str, Any]) -> lsp.SignatureInformation:
+    label = item.get("format") or item.get("label", "")
+    parameters = []
+    for parameter in item.get("parameters", []):
+        name = parameter.get("name", "")
+        parameters.append(
+            lsp.ParameterInformation(
+                label=_parameter_label(label, name),
+                documentation=parameter.get("desc") or None,
+            )
+        )
+
+    return lsp.SignatureInformation(
+        label=label,
+        documentation=item.get("description") or None,
+        parameters=parameters,
+    )
+
+
+def build_signature_help(
+    source: str,
+    tree: Node,
+    position: lsp.Position,
+    custom_signatures: dict[str, list[str]],
+    custom_docs: dict[str, str],
+    builtin_items: list[dict[str, Any]],
+) -> lsp.SignatureHelp | None:
+    call = find_active_call(source, tree, position)
+    if call is None:
+        return None
+
+    if call.name in custom_signatures:
+        signature = _custom_signature(
+            call.name,
+            custom_signatures[call.name],
+            custom_docs.get(call.name),
+        )
+    else:
+        item = next(
+            (item for item in builtin_items if item.get("label") == call.name), None
+        )
+        if item is None:
+            return None
+        signature = _builtin_signature(item)
+
+    parameter_count = len(signature.parameters or [])
+    active_parameter = (
+        min(call.active_argument, parameter_count - 1) if parameter_count else None
+    )
+    signature.active_parameter = active_parameter
+    return lsp.SignatureHelp(
+        signatures=[signature],
+        active_signature=0,
+        active_parameter=active_parameter,
+    )

server/tests/python_tests/test_debug_server.py

@@ -0,0 +1,53 @@
+import sys
+from pathlib import Path
+
+import pytest
+
+
+THIS_DIR = Path(__file__).parent
+SRC_DIR = THIS_DIR.parent.parent / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+import _debug_server
+
+
+def test_debug_endpoint_defaults(monkeypatch):
+    monkeypatch.delenv("NXPS_DEBUG_HOST", raising=False)
+    monkeypatch.delenv("NXPS_DEBUG_PORT", raising=False)
+
+    assert _debug_server._debug_endpoint() == ("127.0.0.1", 5678)
+
+
+@pytest.mark.parametrize("port", ["invalid", "0", "65536"])
+def test_debug_endpoint_rejects_invalid_port(monkeypatch, port):
+    monkeypatch.setenv("NXPS_DEBUG_PORT", port)
+
+    with pytest.raises(RuntimeError):
+        _debug_server._debug_endpoint()
+
+
+def test_connect_debugger_retries_until_adapter_is_ready(monkeypatch):
+    class FakeDebugpy:
+        def __init__(self):
+            self.connect_calls = 0
+            self.wait_calls = 0
+
+        def connect(self, endpoint):
+            assert endpoint == ("127.0.0.1", 5678)
+            self.connect_calls += 1
+            if self.connect_calls < 3:
+                raise ConnectionRefusedError("listener is starting")
+
+        def wait_for_client(self):
+            self.wait_calls += 1
+
+    fake_debugpy = FakeDebugpy()
+    monkeypatch.setattr(_debug_server.time, "sleep", lambda _seconds: None)
+
+    _debug_server._connect_debugger(
+        fake_debugpy, "127.0.0.1", 5678, timeout=1.0
+    )
+
+    assert fake_debugpy.connect_calls == 3
+    assert fake_debugpy.wait_calls == 1

server/tests/python_tests/test_index_stability.py

@@ -0,0 +1,269 @@
+import sys
+from concurrent.futures import ThreadPoolExecutor
+from pathlib import Path
+from threading import Event
+
+THIS_DIR = Path(__file__).parent
+SRC_DIR = THIS_DIR.parent.parent / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+import lsp_server
+import lsprotocol.types as lsp  # type: ignore
+from lsp_tclserver import TclLanguageServer
+from pygls.workspace.text_document import TextDocument
+
+
+def _server() -> TclLanguageServer:
+    return TclLanguageServer(name="stability-test", version="1", max_workers=4)
+
+
+def _document(path: Path, source: str, version: int = 1) -> TextDocument:
+    return TextDocument(
+        uri=path.as_uri(),
+        source=source,
+        version=version,
+        language_id="tcl",
+    )
+
+
+def test_duplicate_proc_stays_indexed_when_other_file_is_removed(tmp_path: Path):
+    server = _server()
+    first = _document(
+        tmp_path / "first.tcl", "proc shared {first} { return $first }"
+    )
+    second = _document(
+        tmp_path / "second.tcl", "proc shared {second} { return $second }"
+    )
+
+    assert server.update_poco_completion_for_file(first)
+    assert server.update_poco_completion_for_file(second)
+    _, signatures, _ = server.index_snapshot()
+    assert "shared" in signatures[first.path]
+    assert "shared" in signatures[second.path]
+
+    server.diagnostics[first.uri] = (first.version, [])
+    server.remove_file_state(first.uri)
+
+    completions, signatures, docs = server.index_snapshot()
+    assert first.path not in completions
+    assert first.path not in signatures
+    assert first.path not in docs
+    assert first.path not in server.navigation_snapshot()
+    assert "shared" in signatures[second.path]
+    assert server.diagnostic_snapshot(first.uri) is None
+
+
+def test_close_replaces_unsaved_index_with_saved_file(tmp_path: Path, monkeypatch):
+    path = tmp_path / "close.tcl"
+    path.write_text("proc saved_proc {} { return }", encoding="utf-8")
+    document = _document(path, "proc unsaved_proc {} { return }")
+    server = _server()
+    server.update_poco_completion_for_file(document)
+    server.get_tree(document)
+    server.get_lines(document)
+    monkeypatch.setattr(lsp_server, "LSP_SERVER", server)
+
+    lsp_server.did_close(
+        lsp.DidCloseTextDocumentParams(
+            text_document=lsp.TextDocumentIdentifier(uri=document.uri)
+        )
+    )
+
+    _, signatures, _ = server.index_snapshot()
+    assert "unsaved_proc" not in signatures[document.path]
+    assert "saved_proc" in signatures[document.path]
+    assert all(key[0] != document.uri for key in server._ast_cache)
+    assert all(key[0] != document.uri for key in server._line_cache)
+
+
+def test_delete_and_rename_notifications_update_index(tmp_path: Path, monkeypatch):
+    server = _server()
+    monkeypatch.setattr(lsp_server, "LSP_SERVER", server)
+
+    deleted_path = tmp_path / "deleted.tcl"
+    deleted = _document(deleted_path, "proc deleted_proc {} { return }")
+    server.update_poco_completion_for_file(deleted)
+    lsp_server.did_delete_files(
+        lsp.DeleteFilesParams(files=[lsp.FileDelete(uri=deleted.uri)])
+    )
+    _, signatures, _ = server.index_snapshot()
+    assert deleted.path not in signatures
+    assert deleted.path not in server.navigation_snapshot()
+
+    old_path = tmp_path / "old.tcl"
+    new_path = tmp_path / "new.tcl"
+    old_path.write_text("proc renamed_proc {} { return }", encoding="utf-8")
+    old_document = _document(old_path, old_path.read_text(encoding="utf-8"))
+    server.update_poco_completion_for_file(old_document)
+    old_path.rename(new_path)
+
+    lsp_server.did_rename_files(
+        lsp.RenameFilesParams(
+            files=[
+                lsp.FileRename(old_uri=old_path.as_uri(), new_uri=new_path.as_uri())
+            ]
+        )
+    )
+
+    _, signatures, _ = server.index_snapshot()
+    assert old_document.path not in signatures
+    renamed_signatures = next(
+        value
+        for indexed_path, value in signatures.items()
+        if server.paths_equal(indexed_path, new_path)
+    )
+    assert "renamed_proc" in renamed_signatures
+    assert any(
+        server.paths_equal(indexed_path, new_path)
+        for indexed_path in server.navigation_snapshot()
+    )
+
+
+def test_parallel_file_indexing_keeps_every_file(tmp_path: Path):
+    server = _server()
+    documents = [
+        _document(
+            tmp_path / f"parallel_{index}.tcl",
+            f"proc parallel_{index} {{value}} {{ return $value }}",
+        )
+        for index in range(20)
+    ]
+
+    with ThreadPoolExecutor(max_workers=8) as executor:
+        results = list(
+            executor.map(
+                lambda document: server.update_poco_completion_for_file(
+                    document, cache_tree=False
+                ),
+                documents,
+            )
+        )
+
+    assert all(results)
+    completions, signatures, _ = server.index_snapshot()
+    assert len(completions) == len(documents)
+    for index, document in enumerate(documents):
+        assert f"parallel_{index}" in signatures[document.path]
+
+
+def test_disk_index_cannot_overwrite_newer_open_document(tmp_path: Path):
+    server = _server()
+    path = tmp_path / "versioned.tcl"
+    open_document = _document(path, "proc current_proc {} { return }", version=5)
+    disk_document = TextDocument(
+        uri=path.as_uri(),
+        source="proc stale_proc {} { return }",
+        version=None,
+        language_id="tcl",
+    )
+
+    assert server.update_poco_completion_for_file(open_document)
+    assert not server.update_poco_completion_for_file(
+        disk_document, cache_tree=False
+    )
+
+    _, signatures, _ = server.index_snapshot()
+    assert "current_proc" in signatures[open_document.path]
+    assert "stale_proc" not in signatures[open_document.path]
+
+
+def test_repeated_lint_does_not_mutate_cached_violations(tmp_path: Path):
+    server = _server()
+    document = _document(
+        tmp_path / "lint.tcl",
+        "proc invalid {{optional 1} required} { return }",
+    )
+
+    first = server.linter(document)
+    second = server.linter(document)
+
+    assert len(first) == 1
+    assert len(second) == 1
+    assert second[0].message == first[0].message
+
+
+def test_diagnostics_keep_latest_document_version(tmp_path: Path):
+    server = _server()
+    path = tmp_path / "diagnostics.tcl"
+    first = _document(path, "set value 1", version=1)
+    latest = _document(path, "set value 2", version=2)
+
+    server.compute_diagnostics(first)
+    server.clear_cache_for_uri(first.uri)
+    server.compute_diagnostics(latest)
+    server.compute_diagnostics(first)
+
+    version, _ = server.diagnostic_snapshot(first.uri)
+    assert version == 2
+
+
+def test_delete_invalidates_in_flight_diagnostics(tmp_path: Path, monkeypatch):
+    server = _server()
+    document = _document(tmp_path / "in_flight.tcl", "set value 1")
+    started = Event()
+    release = Event()
+
+    def slow_diagnostics(_document):
+        started.set()
+        assert release.wait(timeout=5)
+        return []
+
+    monkeypatch.setattr(server, "_compute_diagnostics", slow_diagnostics)
+    with ThreadPoolExecutor(max_workers=1) as executor:
+        future = executor.submit(server.compute_diagnostics, document)
+        assert started.wait(timeout=5)
+        server.remove_file_state(document.uri)
+        release.set()
+        future.result(timeout=5)
+
+    assert server.diagnostic_snapshot(document.uri) is None
+
+
+def test_rapid_changes_analyze_only_latest_snapshot(tmp_path: Path, monkeypatch):
+    server = _server()
+    path = tmp_path / "debounced.tcl"
+    first = _document(path, "set value 1", version=1)
+    latest = _document(path, "set value 2", version=2)
+    calls = []
+    completed = Event()
+
+    monkeypatch.setattr(
+        server,
+        "compute_diagnostics",
+        lambda document: calls.append(("diagnostics", document.version)),
+    )
+
+    def record_index(document):
+        calls.append(("index", document.version))
+        completed.set()
+        return True
+
+    monkeypatch.setattr(server, "update_poco_completion_for_file", record_index)
+
+    server.schedule_document_analysis(first, delay_seconds=0.05)
+    server.schedule_document_analysis(latest, delay_seconds=0.05)
+
+    assert completed.wait(timeout=2)
+    assert calls == [("diagnostics", 2), ("index", 2)]
+
+
+def test_variable_and_workspace_request_caches_are_reused(tmp_path: Path):
+    server = _server()
+    document = _document(
+        tmp_path / "cached.tcl",
+        "proc cached_proc {argument} { set local_value $argument }",
+    )
+
+    assert server.update_poco_completion_for_file(document)
+    first_variables = server.variable_index_for_document(document)
+    second_variables = server.variable_index_for_document(document)
+    first_completions = server.completion_items_snapshot()
+    second_completions = server.completion_items_snapshot()
+    first_names = server.custom_function_names_snapshot()
+    second_names = server.custom_function_names_snapshot()
+
+    assert first_variables is second_variables
+    assert first_completions is second_completions
+    assert first_names is second_names
+    assert "cached_proc" in first_names

server/tests/python_tests/test_inlay_hint.py

@@ -0,0 +1,209 @@
+import sys
+from pathlib import Path
+
+THIS_DIR = Path(__file__).parent
+SRC_DIR = THIS_DIR.parent.parent / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+import lsprotocol.types as lsp  # type: ignore
+from tools.inlay_hint import (
+    InlayHintGenerator,
+    InlayHintParameter,
+    InlayHintSignature,
+    build_builtin_inlay_signatures,
+    build_custom_inlay_signatures,
+)
+from tools.navigation import build_file_symbol_index
+from tools.parser import CustomParser
+
+
+def _signature(*names: str, variadic: bool = False) -> InlayHintSignature:
+    parameters = tuple(
+        InlayHintParameter(
+            name=name,
+            variadic=variadic and index == len(names) - 1,
+        )
+        for index, name in enumerate(names)
+    )
+    return InlayHintSignature(
+        parameters=parameters,
+        display_label=" ".join(["test_proc", *names]),
+    )
+
+
+def _generate(
+    source: str,
+    signatures: dict[str, InlayHintSignature],
+    **options,
+) -> list[lsp.InlayHint]:
+    tree = CustomParser().parse(source)
+    generator = InlayHintGenerator(source, signatures, **options)
+    return generator.generate(tree)
+
+
+def _labels(hints: list[lsp.InlayHint]) -> list[str]:
+    labels = []
+    for hint in hints:
+        if isinstance(hint.label, str):
+            labels.append(hint.label)
+        else:
+            labels.append("".join(part.value for part in hint.label))
+    return labels
+
+
+def test_many_parameters_are_returned_without_server_side_truncation():
+    names = tuple(f"parameter_{index}" for index in range(10))
+    source = "test_proc " + " ".join(str(index) for index in range(10))
+
+    hints = _generate(source, {"test_proc": _signature(*names)})
+
+    assert _labels(hints) == [f"{name}:" for name in names]
+    assert all("…" not in label and "..." not in label for label in _labels(hints))
+
+
+def test_only_hints_inside_requested_range_are_returned():
+    source = "test_proc first\nset spacer 1\ntest_proc second"
+    requested_range = lsp.Range(
+        start=lsp.Position(line=2, character=0),
+        end=lsp.Position(line=3, character=0),
+    )
+
+    hints = _generate(
+        source,
+        {"test_proc": _signature("value")},
+        requested_range=requested_range,
+    )
+
+    assert len(hints) == 1
+    assert hints[0].position.line == 2
+
+
+def test_range_walk_keeps_nested_commands_inside_proc_body():
+    source = "proc wrapper {} {\n    test_proc nested\n}"
+    requested_range = lsp.Range(
+        start=lsp.Position(line=1, character=0),
+        end=lsp.Position(line=2, character=0),
+    )
+
+    hints = _generate(
+        source,
+        {"test_proc": _signature("value")},
+        requested_range=requested_range,
+    )
+
+    assert _labels(hints) == ["value:"]
+    assert hints[0].position.line == 1
+
+
+def test_matching_variable_name_can_be_suppressed():
+    source = "test_proc $value $other"
+    signature = _signature("value", "result")
+
+    suppressed = _generate(source, {"test_proc": signature})
+    visible = _generate(
+        source,
+        {"test_proc": signature},
+        suppress_when_argument_matches_name=False,
+    )
+
+    assert _labels(suppressed) == ["result:"]
+    assert _labels(visible) == ["value:", "result:"]
+
+
+def test_literal_mode_hides_variable_argument_hints():
+    source = 'test_proc $value "literal"'
+
+    hints = _generate(
+        source,
+        {"test_proc": _signature("first", "second")},
+        parameter_names="literals",
+    )
+
+    assert _labels(hints) == ["second:"]
+
+
+def test_variadic_parameter_labels_every_remaining_argument():
+    hints = _generate(
+        "test_proc first second third fourth",
+        {"test_proc": _signature("required", "args", variadic=True)},
+    )
+
+    assert _labels(hints) == ["required:", "args:", "args:", "args:"]
+
+
+def test_builtin_signature_has_variadic_hints_and_parameter_documentation():
+    signatures = build_builtin_inlay_signatures(
+        [
+            {
+                "label": "MOM_force",
+                "description": "Controls address output.",
+                "format": "MOM_force <mode> <address_1 ... address_n>",
+                "parameters": [
+                    {"name": "mode", "desc": "Output mode."},
+                    {
+                        "name": "address_1 ... address_n",
+                        "desc": "Output addresses.",
+                    },
+                ],
+            }
+        ]
+    )
+
+    hints = _generate("MOM_force Always X Y", signatures)
+
+    assert _labels(hints) == ["mode:", "address:", "address:"]
+    assert hints[1].label[0].tooltip == "Output addresses."  # type: ignore[index]
+    assert hints[0].tooltip.value.endswith("Controls address output.")  # type: ignore[union-attr]
+
+
+def test_current_file_signature_and_definition_location_take_priority(tmp_path: Path):
+    other_path = tmp_path / "other.tcl"
+    current_path = tmp_path / "current.tcl"
+    other_source = "proc shared {from_other} { return $from_other }"
+    current_source = "proc shared {from_current args} { return $from_current }"
+    parser = CustomParser()
+    other_tree = parser.parse(other_source)
+    current_tree = parser.parse(current_source)
+    indexes = {
+        str(other_path): build_file_symbol_index(
+            str(other_path), other_path.as_uri(), other_tree
+        ),
+        str(current_path): build_file_symbol_index(
+            str(current_path), current_path.as_uri(), current_tree
+        ),
+    }
+
+    signatures = build_custom_inlay_signatures(
+        {
+            str(current_path): {"shared": ["from_current", "args"]},
+            str(other_path): {"shared": ["from_other"]},
+        },
+        {
+            str(current_path): {"shared": "Current documentation."},
+            str(other_path): {"shared": "Other documentation."},
+        },
+        indexes,
+        str(current_path),
+    )
+
+    signature = signatures["shared"]
+    assert [parameter.name for parameter in signature.parameters] == [
+        "from_current",
+        "args",
+    ]
+    assert signature.parameters[-1].variadic
+    assert signature.documentation == "Current documentation."
+    assert signature.location is not None
+    assert signature.location.uri == current_path.as_uri()
+
+
+def test_positions_use_lsp_utf16_offsets():
+    source = 'test_proc "😀" second'
+
+    hints = _generate(
+        source,
+        {"test_proc": _signature("first", "second")},
+    )
+
+    assert hints[1].position.character == source.index("second") + 1

server/tests/python_tests/test_navigation.py

@@ -0,0 +1,271 @@
+import sys
+from pathlib import Path
+
+
+THIS_DIR = Path(__file__).parent
+SRC_DIR = THIS_DIR.parent.parent / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+import lsprotocol.types as lsp  # type: ignore
+from pygls.workspace.text_document import TextDocument
+
+import lsp_server
+from lsp_tclserver import TclLanguageServer
+from tools.navigation import (
+    SymbolIdentity,
+    build_file_symbol_index,
+    definition_identities,
+    matching_occurrences,
+    symbol_at_position,
+    workspace_symbols,
+)
+from tools.parser import CustomParser
+
+
+def _index(path: Path, source: str):
+    return build_file_symbol_index(
+        str(path), path.as_uri(), CustomParser().parse(source)
+    )
+
+
+def _document(path: Path, source: str) -> TextDocument:
+    return TextDocument(
+        uri=path.as_uri(),
+        source=source,
+        version=1,
+        language_id="tcl",
+    )
+
+
+def _position(source: str, token: str, occurrence: int = 0) -> lsp.Position:
+    offset = -1
+    for _ in range(occurrence + 1):
+        offset = source.index(token, offset + 1)
+    before = source[:offset]
+    return lsp.Position(
+        line=before.count("\n"),
+        character=offset - (before.rfind("\n") + 1),
+    )
+
+
+def _range_text(source: str, range_: lsp.Range) -> str:
+    assert range_.start.line == range_.end.line
+    line = source.splitlines()[range_.start.line]
+    return line[range_.start.character : range_.end.character]
+
+
+def test_proc_references_respect_namespaces_and_root_fallback(tmp_path: Path):
+    first_source = """proc shared {value} { return $value }
+namespace eval shop {
+    proc shared {value} { return $value }
+    proc call {} { shared 1 }
+}
+"""
+    second_source = """shared 2
+namespace eval shop { shared 3 }
+::shop::shared 4
+"""
+    first = _index(tmp_path / "first.tcl", first_source)
+    second = _index(tmp_path / "second.tcl", second_source)
+    indexes = {first.path: first, second.path: second}
+    definitions = definition_identities(indexes)
+
+    root = SymbolIdentity(kind="proc", name="::shared")
+    namespaced = SymbolIdentity(kind="proc", name="::shop::shared")
+
+    assert len(matching_occurrences(root, indexes, definitions)) == 2
+    assert len(matching_occurrences(namespaced, indexes, definitions)) == 4
+
+
+def test_local_variable_identity_does_not_leak_between_procs(tmp_path: Path):
+    source = """proc first {} {
+    set value 1
+    puts $value
+}
+proc second {} {
+    set value 2
+    puts $value
+}
+"""
+    index = _index(tmp_path / "locals.tcl", source)
+    indexes = {index.path: index}
+    definitions = definition_identities(indexes)
+    position = _position(source, "$value")
+    result = symbol_at_position(
+        index,
+        lsp.Position(position.line, position.character + 1),
+        definitions,
+    )
+
+    assert result is not None
+    _, identity = result
+    matches = matching_occurrences(identity, indexes, definitions)
+    assert len(matches) == 2
+    assert all(match.identity.scope and "::first" in match.identity.scope for _, match in matches)
+
+
+def test_foreach_binding_can_be_renamed_without_touching_other_proc(
+    tmp_path: Path,
+):
+    source = """proc first {items} {
+    foreach item $items { puts $item }
+}
+proc second {items} {
+    foreach item $items { puts $item }
+}
+"""
+    index = _index(tmp_path / "foreach.tcl", source)
+    indexes = {index.path: index}
+    definitions = definition_identities(indexes)
+    position = _position(source, "item", occurrence=1)
+    result = symbol_at_position(index, position, definitions)
+
+    assert result is not None
+    _, identity = result
+    matches = matching_occurrences(identity, indexes, definitions)
+    assert identity in definitions
+    assert len(matches) == 2
+    assert all("::first" in (occurrence.identity.scope or "") for _, occurrence in matches)
+
+
+def test_variable_ranges_preserve_qualifiers_and_tcl_substitution(tmp_path: Path):
+    source = """namespace eval shop {
+    variable value 0
+    proc use {} {
+        variable value
+        set value 1
+        puts ${value}
+    }
+}
+set ::shop::value 2
+"""
+    index = _index(tmp_path / "variables.tcl", source)
+    indexes = {index.path: index}
+    definitions = definition_identities(indexes)
+    identity = SymbolIdentity(kind="variable", name="::shop::value")
+    matches = matching_occurrences(identity, indexes, definitions)
+
+    assert len(matches) == 5
+    assert all(_range_text(source, occurrence.range) == "value" for _, occurrence in matches)
+
+
+def test_qualified_proc_body_and_variable_import_use_declared_namespace(
+    tmp_path: Path,
+):
+    source = """namespace eval current {
+    proc ::other::use {} {
+        variable value
+        puts $value
+        variable ::external::setting
+        puts $setting
+    }
+}
+namespace eval other { variable value 1 }
+namespace eval external { variable setting 2 }
+"""
+    index = _index(tmp_path / "qualified.tcl", source)
+    indexes = {index.path: index}
+    definitions = definition_identities(indexes)
+
+    other_value = SymbolIdentity(kind="variable", name="::other::value")
+    external_setting = SymbolIdentity(
+        kind="variable", name="::external::setting"
+    )
+    assert len(matching_occurrences(other_value, indexes, definitions)) == 3
+    assert len(matching_occurrences(external_setting, indexes, definitions)) == 3
+
+
+def test_workspace_symbols_include_procs_namespaces_and_global_variables(tmp_path: Path):
+    source = """set globalValue 1
+set globalValue 2
+proc rootProc {} { return }
+namespace eval shop { proc namespacedProc {} { return } }
+"""
+    index = _index(tmp_path / "symbols.tcl", source)
+
+    symbols = workspace_symbols({index.path: index}, "")
+    names = [symbol.name for symbol in symbols]
+
+    assert names.count("globalValue") == 1
+    assert "rootProc" in names
+    assert "shop" in names
+    assert "shop::namespacedProc" in names
+
+
+def test_lsp_references_definition_rename_and_workspace_symbols(
+    tmp_path: Path, monkeypatch
+):
+    declaration_source = "proc customProc {value} { return $value }\n"
+    usage_source = "set result [customProc 1]\n"
+    declaration = _document(tmp_path / "declaration.tcl", declaration_source)
+    usage = _document(tmp_path / "usage.tcl", usage_source)
+    server = TclLanguageServer(name="navigation-test", version="1", max_workers=1)
+    assert server.update_poco_completion_for_file(declaration)
+    assert server.update_poco_completion_for_file(usage)
+    monkeypatch.setattr(lsp_server, "LSP_SERVER", server)
+    position = _position(usage_source, "customProc")
+    identifier = lsp.TextDocumentIdentifier(uri=usage.uri)
+
+    definitions = lsp_server.goto_definition(
+        lsp.DefinitionParams(text_document=identifier, position=position)
+    )
+    assert definitions is not None
+    assert len(definitions) == 1
+    assert definitions[0].uri == declaration.uri
+
+    references = lsp_server.references(
+        lsp.ReferenceParams(
+            text_document=identifier,
+            position=position,
+            context=lsp.ReferenceContext(include_declaration=True),
+        )
+    )
+    assert len(references) == 2
+
+    prepared = lsp_server.prepare_rename(
+        lsp.PrepareRenameParams(text_document=identifier, position=position)
+    )
+    assert prepared is not None
+    assert prepared.placeholder == "customProc"
+
+    edit = lsp_server.rename(
+        lsp.RenameParams(
+            text_document=identifier,
+            position=position,
+            new_name="renamedProc",
+        )
+    )
+    assert edit is not None
+    assert edit.changes is not None
+    assert set(edit.changes) == {declaration.uri, usage.uri}
+    assert all(
+        text_edit.new_text == "renamedProc"
+        for edits in edit.changes.values()
+        for text_edit in edits
+    )
+
+    symbols = lsp_server.workspace_symbol(
+        lsp.WorkspaceSymbolParams(query="custom")
+    )
+    assert [symbol.name for symbol in symbols] == ["customProc"]
+
+
+def test_duplicate_proc_definition_cannot_be_renamed(tmp_path: Path, monkeypatch):
+    server = TclLanguageServer(name="navigation-test", version="1", max_workers=1)
+    documents = [
+        _document(tmp_path / f"duplicate_{number}.tcl", "proc duplicate {} { return }")
+        for number in range(2)
+    ]
+    for document in documents:
+        assert server.update_poco_completion_for_file(document)
+    monkeypatch.setattr(lsp_server, "LSP_SERVER", server)
+
+    result = lsp_server.prepare_rename(
+        lsp.PrepareRenameParams(
+            text_document=lsp.TextDocumentIdentifier(uri=documents[0].uri),
+            position=lsp.Position(line=0, character=6),
+        )
+    )
+
+    assert result is None

server/tests/python_tests/test_signature_help.py

@@ -0,0 +1,92 @@
+import sys
+from pathlib import Path
+
+
+THIS_DIR = Path(__file__).parent
+SRC_DIR = THIS_DIR.parent.parent / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+import lsprotocol.types as lsp  # type: ignore
+
+from common.load_data import standard_items
+from tools.parser import CustomParser
+from tools.signature_help import build_signature_help, find_active_call
+
+
+CUSTOM_SIGNATURES = {
+    "SERVICE_spacer_output": ["type", "length", "line_num", "output"]
+}
+
+
+def test_custom_proc_signature_and_active_parameter():
+    source = 'SERVICE_spacer_output "*" '
+    tree = CustomParser().parse(source)
+
+    result = build_signature_help(
+        source,
+        tree,
+        lsp.Position(line=0, character=len(source)),
+        CUSTOM_SIGNATURES,
+        {"SERVICE_spacer_output": "Outputs a spacer line."},
+        [],
+    )
+
+    assert result is not None
+    assert result.active_parameter == 1
+    signature = result.signatures[0]
+    assert signature.label == "SERVICE_spacer_output type length line_num output"
+    assert (  # type: ignore[union-attr]
+        signature.documentation.value == "Outputs a spacer line."
+    )
+    assert signature.parameters is not None
+    assert signature.parameters[3].label == (43, 49)
+
+
+def test_innermost_command_is_used_for_nested_call():
+    source = 'set result [SERVICE_spacer_output "*" 20]'
+    tree = CustomParser().parse(source)
+    position = lsp.Position(line=0, character=source.index("20"))
+
+    call = find_active_call(source, tree, position)
+
+    assert call is not None
+    assert call.name == "SERVICE_spacer_output"
+    assert call.active_argument == 1
+
+
+def test_builtin_signature_includes_parameter_documentation():
+    source = "MOM_abort "
+    tree = CustomParser().parse(source)
+
+    result = build_signature_help(
+        source,
+        tree,
+        lsp.Position(line=0, character=len(source)),
+        {},
+        {},
+        standard_items.json_data["MOM_procs"],
+    )
+
+    assert result is not None
+    assert result.active_parameter == 0
+    signature = result.signatures[0]
+    assert signature.label == "MOM_abort <message>"
+    assert signature.parameters is not None
+    assert signature.parameters[0].documentation
+
+
+def test_unknown_command_has_no_signature_help():
+    source = "unknown_custom_command "
+    tree = CustomParser().parse(source)
+
+    result = build_signature_help(
+        source,
+        tree,
+        lsp.Position(line=0, character=len(source)),
+        {},
+        {},
+        standard_items.json_data["MOM_procs"],
+    )
+
+    assert result is None

test/test.tcl

@@ -114,3 +114,6 @@ proc SERVICE_get_tool_data {} {
 LIB_GE_command_buffer_edit_replace MOM_end_of_program_LIB END_OF_PROGRAM @END_OF_PROG {
     MOM_do_template "end_of_program_rewind"
 } EndOfProgramRewind
+
+
+SERVICE_remove_file "test"