add signature help

server/src/lsp_server.py

@@ -46,6 +46,7 @@ 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 tools.signature_help import get_signature_help
 from lsp_tclserver import TclLanguageServer
 
 
@@ -235,6 +236,22 @@ def semantic_tokens(params: lsp.SemanticTokensParams):
     return lsp.SemanticTokens(data=data)
 
 
+@LSP_SERVER.feature(
+    lsp.TEXT_DOCUMENT_SIGNATURE_HELP,
+    lsp.SignatureHelpOptions(trigger_characters=[" ", "\t", "[", ",", "(", "{", '"', "'"], retrigger_characters=list("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_:$\"'{}[]() ,\t")),
+)
+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)
+
+    # Merge proc signatures across files
+    merged_signatures = {}
+    for sigs in LSP_SERVER.proc_signatures.values():
+        merged_signatures.update(sigs)
+
+    return get_signature_help(document.source, tree, merged_signatures, params.position)
+
+
 @LSP_SERVER.feature(lsp.TEXT_DOCUMENT_HOVER)
 def hover(params: lsp.HoverParams) -> lsp.Hover:
     pos = params.position