feat: add syntaxHighlightingOnly setting (#85)

Adds a `jaclang-extension.syntaxHighlightingOnly` boolean setting (default
false). When enabled, the extension skips EnvManager initialization and
LSP startup, and the Jac-specific menu/context commands (run, debug,
restart language server, serve, lintfix) are hidden via `when` clauses.

Useful for environments where users only need syntax highlighting and
do not have a Jac runtime installed.

Author: kugesan1105

package.json

@@ -41,6 +41,11 @@
           "type": "boolean",
           "default": false,
           "description": "Enable developer mode to use experimental language server features"
+        },
+        "jaclang-extension.syntaxHighlightingOnly": {
+          "type": "boolean",
+          "default": false,
+          "description": "Enable syntax highlighting only. Disables the Jac language server and environment selection (no type checking, diagnostics, go-to-definition, hover, or completion)."
         }
       }
     },
@@ -91,30 +96,30 @@
         {
           "command": "jaclang-extension.runCurrentFile",
           "group": "navigation@0",
-          "when": "resourceLangId == jac"
+          "when": "resourceLangId == jac && !config.jaclang-extension.syntaxHighlightingOnly"
         },
         {
           "command": "jaclang-extension.debugCurrentFile",
           "group": "navigation@1",
-          "when": "resourceLangId == jac"
+          "when": "resourceLangId == jac && !config.jaclang-extension.syntaxHighlightingOnly"
         }
       ],
       "editor/title": [
         {
           "command": "jaclang-extension.restartLanguageServer",
           "group": "navigation@98",
-          "when": "resourceLangId == jac && config.jaclang-extension.developerMode"
+          "when": "resourceLangId == jac && config.jaclang-extension.developerMode && !config.jaclang-extension.syntaxHighlightingOnly"
         },
         {
           "command": "jaclang-extension.serveCurrentFile",
           "group": "navigation@99",
-          "when": "resourceLangId == jac && config.jaclang-extension.showServeCommand"
+          "when": "resourceLangId == jac && config.jaclang-extension.showServeCommand && !config.jaclang-extension.syntaxHighlightingOnly"
         }
       ],
       "editor/context": [
         {
           "command": "jac.lintfixFormat",
-          "when": "resourceLangId == jac",
+          "when": "resourceLangId == jac && !config.jaclang-extension.syntaxHighlightingOnly",
           "group": "1_modification"
         }
       ],

src/extension.ts

@@ -16,6 +16,12 @@ export function getEnvManager(): EnvManager | undefined {
     return envManager;
 }
 
+export function isSyntaxHighlightingOnly(): boolean {
+  return vscode.workspace
+    .getConfiguration("jaclang-extension")
+    .get<boolean>("syntaxHighlightingOnly", false);
+}
+
 // Create and start LSP Manager if not already running
 export async function createAndStartLsp(
   envManager: EnvManager,
@@ -37,18 +43,24 @@ export async function activate(context: vscode.ExtensionContext) {
   try {
     envManager = new EnvManager(context);
     registerAllCommands(context, envManager);
-    await envManager.init();
+
+    const highlightOnly = isSyntaxHighlightingOnly();
+    if (!highlightOnly) {
+      await envManager.init();
+    }
 
     setupVisualDebuggerWebview(context);
 
-    const jacPath = envManager.getJacPath();
-    const isJacAvailable = await validateJacExecutable(jacPath); // Check if Jac is available before starting LSP
+    if (!highlightOnly) {
+      const jacPath = envManager.getJacPath();
+      const isJacAvailable = await validateJacExecutable(jacPath); // Check if Jac is available before starting LSP
 
-    if (isJacAvailable) {
-      try {
-        await createAndStartLsp(envManager, context);
-      } catch (error) {
-        console.error("LSP failed to start during activation:", error);
+      if (isJacAvailable) {
+        try {
+          await createAndStartLsp(envManager, context);
+        } catch (error) {
+          console.error("LSP failed to start during activation:", error);
+        }
       }
     }
 
@@ -63,4 +75,4 @@ export async function activate(context: vscode.ExtensionContext) {
 
 export function deactivate(): Thenable<void> | undefined {
   return lspManager?.stop();
-}
+}