feat: go-to-definition + fix tab sync and unused-binding diagnostics

crate/src/lib.rs

@@ -893,10 +893,34 @@ impl ParsedDocument {
             }
         }
 
+        let is_multi_expr = matches!(&parse_result.root.kind,
+            NodeKind::Module(exprs) if exprs.items.len() > 1);
+
         for bind_idx in bind_sites {
             if used_binds.contains(&bind_idx) { continue; }
             let cps_id = CpsId(bind_idx);
-            if resolved.bind_scope.get(cps_id) == &Some(root_scope_id) { continue; }
+
+            // Skip non-Ident bind sites (synthetic CPS nodes from lambdas,
+            // pattern matching, etc.)
+            let is_ident = cps.origin.get(cps_id)
+                .and_then(|ast_id| *ast_index.get(ast_id))
+                .is_some_and(|node| matches!(&node.kind, NodeKind::Ident(_)));
+            if !is_ident { continue; }
+
+            // Skip module-level bindings (they are exports).
+            // Single-expr module: bindings are directly in root scope.
+            // Multi-expr module: bindings are in the synthetic module fn
+            // scope, whose parent_scope is root.
+            if let Some(scope) = resolved.bind_scope.get(cps_id) {
+                if *scope == root_scope_id { continue; }
+                if is_multi_expr {
+                    let parent_is_root = resolved.parent_scope.try_get(*scope)
+                        .and_then(|p| *p)
+                        .is_some_and(|parent| parent == root_scope_id);
+                    if parent_is_root { continue; }
+                }
+            }
+
             if let Some(ast_id) = *cps.origin.get(cps_id) {
                 if let Some(node) = *ast_index.get(ast_id) {
                     let line = node.loc.start.line.saturating_sub(1);
@@ -905,7 +929,7 @@ impl ParsedDocument {
                     let end_col = node.loc.end.col;
                     let name = match &node.kind {
                         NodeKind::Ident(s) => s.replace('\\', "\\\\").replace('"', "\\\""),
-                        _ => "?".to_string(),
+                        _ => continue,
                     };
                     diag_entries.push(format!(
                         r#"{{"line":{line},"col":{col},"endLine":{end_line},"endCol":{end_col},"message":"unused binding '{name}'","source":"name_res","severity":"warning"}}"#

src/ast-panel.ts

@@ -105,12 +105,6 @@ export class AstPanel {
 
     this.renderNode(root, this.container, 0)
     this.rebuildFlat()
-
-    // Sync with current cursor position after update
-    const pos = this.editor.getPosition()
-    if (pos) {
-      this.highlightAtPosition(pos.lineNumber - 1, pos.column - 1)
-    }
   }
 
   // Render one node as a group (row + children wrapper) and recurse.

src/main.ts

@@ -32,6 +32,8 @@ import 'monaco-editor/esm/vs/editor/contrib/wordHighlighter/browser/highlightDec
 import 'monaco-editor/esm/vs/editor/contrib/caretOperations/browser/caretOperations.js'   // transpose chars
 import 'monaco-editor/esm/vs/editor/contrib/cursorUndo/browser/cursorUndo.js'             // cursor stack undo
 import 'monaco-editor/esm/vs/editor/contrib/hover/browser/hoverContribution.js'           // hover tooltips (diagnostics, symbols)
+import 'monaco-editor/esm/vs/editor/contrib/gotoSymbol/browser/goToCommands.js'           // go-to-definition (F12 / Cmd+click)
+import 'monaco-editor/esm/vs/editor/contrib/gotoSymbol/browser/link/goToDefinitionAtPosition.js' // Ctrl/Cmd+click inline
 import { compile } from './compiler.js'
 import { run } from './wasi-shim.js'
 import { FinkTokenizer, type LexToken } from './tokenizer.js'
@@ -59,6 +61,11 @@ let lastSemanticTokens: Uint32Array = new Uint32Array(0)
 let lastDiagnostics: string = '[]'
 let lastParseMs = 0
 
+// Last ParsedDocument kept alive for cursor-time queries (go-to-def, references).
+// Freed and replaced on every successful re-parse.
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+let lastDoc: any = null
+
 // Forward declaration — defined after the editor is created (needs DOM + editor).
 let applyDiagnosticToggles: () => void = () => {}
 
@@ -105,7 +112,9 @@ function _reparse(src: string, _modelVersion: number): void {
     lastDiagnostics = doc.get_diagnostics()
     cpsJson = doc.get_cps()
     cpsLiftedJson = doc.get_cps_lifted()
-    doc.free()
+    // Keep doc alive for cursor-time queries (go-to-def, references).
+    if (lastDoc) try { lastDoc.free() } catch (_) { /* already freed */ }
+    lastDoc = doc
   } catch (e) {
     console.warn('[fink] CPS analysis crashed (name resolution disabled):', e)
     try { doc.free() } catch (_) { /* handle already poisoned */ }
@@ -235,6 +244,27 @@ monaco.languages.registerDocumentSemanticTokensProvider('fink', {
   releaseDocumentSemanticTokens() {},
 })
 
+// Definition provider — delegates to the WASM ParsedDocument kept alive across
+// re-parses. Requires run_analysis() to have succeeded (name resolution).
+monaco.languages.registerDefinitionProvider('fink', {
+  provideDefinition(model, position) {
+    if (!lastDoc) return undefined
+    // Monaco positions are 1-based; WASM API is 0-based.
+    const data: Uint32Array = lastDoc.get_definition(
+      position.lineNumber - 1,
+      position.column - 1,
+    )
+    if (data.length !== 4) return undefined
+    return {
+      uri: model.uri,
+      range: new monaco.Range(
+        data[0] + 1, data[1] + 1,
+        data[2] + 1, data[3] + 1,
+      ),
+    }
+  },
+})
+
 // ---------------------------------------------------------------------------
 // Theme — reads colors from CSS variables (set by embedding page or dev wrapper)
 // ---------------------------------------------------------------------------
@@ -382,6 +412,18 @@ for (const tab of document.querySelectorAll<HTMLElement>('.fink-tab')) {
     if (!SYNC_TABS.has(activeTab)) {
       // Passive tab (e.g. Output) — clear all decorations and stop syncing.
       clearAllDecorations()
+    } else {
+      // Sync tab activated — sync to current cursor position.
+      clearAllDecorations()
+      const pos = editor.getPosition()
+      if (pos) {
+        const line = pos.lineNumber - 1
+        const col = pos.column - 1
+        if (activeTab === 'fink-tokens') tokensPanel?.highlightAtPosition(line, col)
+        if (activeTab === 'fink-ast') astPanel?.highlightAtPosition(line, col)
+        if (activeTab === 'fink-cps') cpsPanel?.syncFromSource(line, col)
+        if (activeTab === 'fink-cps-lifted') cpsPanelLifted?.syncFromSource(line, col)
+      }
     }
   })
 }

src/tokens-panel.ts

@@ -96,12 +96,6 @@ export class TokensPanel {
 
     this.container.innerHTML = ''
     this.container.appendChild(frag)
-
-    // Sync with current cursor position
-    const pos = this.editor.getPosition()
-    if (pos) {
-      this.highlightAtPosition(pos.lineNumber - 1, pos.column - 1)
-    }
   }
 
   clearEditorHighlight(): void {