feat(inlay-hints): add configurable parameter name hints

Adds configurable inlay hints for TCL procedures and merges signatures from built-ins and workspace files. The feature supports parameterNames and suppressWhenArgumentMatchesName and respects an optional range filter and current-file priority.

- Introduces built-in and custom inlay hint builders
- Honors inlayHints parameterNames and suppression options
- Adds tests validating hints, ranges, and priority rules

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 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

README.md

@@ -31,6 +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
 

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)

package.json

@@ -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.",
@@ -120,6 +140,11 @@
           "type": "array"
         }
       }
+    },
+    "configurationDefaults": {
+      "[tcl]": {
+        "editor.inlayHints.maximumLength": 0
+      }
     }
   },
   "scripts": {

server/src/lsp_server.py

@@ -44,7 +44,11 @@ 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.inlay_hint import InlayHintGenerator
+from tools.inlay_hint import (
+    InlayHintGenerator,
+    build_builtin_inlay_signatures,
+    build_custom_inlay_signatures,
+)
 from tools.navigation import (
     SymbolIdentity,
     definition_identities,
@@ -333,20 +337,43 @@ 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.
-    _, proc_signatures, _ = LSP_SERVER.index_snapshot()
+    signatures = build_builtin_inlay_signatures(
-    for sigs in proc_signatures.values():
+        standard_items.json_data.get("MOM_procs", [])
-        merged_signatures.update(sigs)
+    )
+    _, proc_signatures, proc_docs = LSP_SERVER.index_snapshot()
+    signatures.update(
+        build_custom_inlay_signatures(
+            proc_signatures,
+            proc_docs,
+            LSP_SERVER.navigation_snapshot(),
+            document.path,
+        )
+    )
 
-    generator = InlayHintGenerator(merged_signatures)
+    generator = InlayHintGenerator(
+        document.source,
+        signatures,
+        requested_range=params.range,
+        parameter_names=parameter_names,
+        suppress_when_argument_matches_name=inlay_settings.get(
+            "suppressWhenArgumentMatchesName", True
+        ),
+    )
     tree.accept(generator, recurse=True)
     return generator.hints
 
@@ -769,6 +796,13 @@ 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/tools/inlay_hint.py

@@ -1,29 +1,229 @@
+from __future__ import annotations
+
+import os
+import re
+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_location(
+    index: FileSymbolIndex | None, proc_name: str
+) -> lsp.Location | None:
+    if index is None:
+        return None
+
+    basename = proc_name.removeprefix("::").rsplit("::", 1)[-1]
+    for occurrence in reversed(index.occurrences):
+        if (
+            occurrence.is_definition
+            and occurrence.identity.kind == "proc"
+            and occurrence.placeholder == basename
+        ):
+            return lsp.Location(uri=index.uri, range=occurrence.range)
+    return None
+
+
+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, {})
+        index = 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_location(index, proc_name),
+            )
+    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: dict[str, InlayHintSignature],
+        *,
+        requested_range: lsp.Range | None = None,
+        parameter_names: str = "all",
+        suppress_when_argument_matches_name: bool = True,
+    ):
+        self.source_lines = 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 _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)
-                self.hints.append(
+            if not _position_in_range(position, self.requested_range):
-                    lsp.InlayHint(
+                continue
-                        position=lsp.Position(line=line - 1, character=col - 1),
+
-                        label=f"{param_name}:",
+            label = lsp.InlayHintLabelPart(
-                        kind=lsp.InlayHintKind.Parameter,
+                value=f"{parameter.name}:",
-                    )
+                tooltip=parameter.documentation,
+                location=signature.location,
+            )
+            self.hints.append(
+                lsp.InlayHint(
+                    position=position,
+                    label=[label],
+                    kind=lsp.InlayHintKind.Parameter,
+                    tooltip=self._tooltip(signature),
                 )
+            )

server/tests/python_tests/test_inlay_hint.py

@@ -0,0 +1,194 @@
+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)
+    tree.accept(generator, recurse=True)
+    return generator.hints
+
+
+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_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