Early codeaction support

package.json

@@ -1,7 +1,7 @@
 {
     "name": "miller",
     "productName": "miller",
-    "version": "0.2.3",
+    "version": "0.2.4",
     "description": "Column-based code editor",
     "main": ".vite/build/main.js",
     "scripts": {

src/app/lsp.ts

@@ -1,6 +1,4 @@
-// Minimal LSP integration helper for the editor.
-// Keeps all LSP-specific logic in one place so it's easy to review.
-
+import type * as lsp from "vscode-languageserver-protocol";
 import { Extension, TransactionSpec } from "@codemirror/state";
 import { EditorView } from "@codemirror/view";
 
@@ -10,6 +8,7 @@ import {
     Workspace,
     hoverTooltips,
     signatureHelp,
+    WorkspaceMapping
 } from "@codemirror/lsp-client";
 
 import { serverCompletion } from "./lsp/completion";
@@ -79,6 +78,23 @@ export function inferLanguageFromPath(
     if (ext === "ts" || ext === "tsx" || ext === "js" || ext === "jsx")
         return "typescript";
     if (ext === "py") return "python";
+    if (ext === "c" || ext === "h" || ext === "cpp" || ext === "hpp")
+        return "cpp";
+    if (ext === "java") return "java";
+    if (ext === "go") return "go";
+    if (ext === "rs") return "rust";
+    if (ext === "php") return "php";
+    if (ext === "rb") return "ruby";
+    if (ext === "cs") return "csharp";
+    if (ext === "html" || ext === "htm") return "html";
+    if (ext === "css" || ext === "scss" || ext === "less") return "css";
+    if (ext === "json") return "json";
+    if (ext === "xml") return "xml";
+    if (ext === "yaml" || ext === "yml") return "yaml";
+    if (ext === "md") return "markdown";
+    if (ext === "lua") return "lua";
+    if (ext === "sh" || ext === "bash") return "shellscript";
+    if (ext === "hs") return "haskell";
     // add more mappings as needed
     return undefined;
 }
@@ -158,6 +174,22 @@ class OpenFileWorkspace extends Workspace {
     }
 }
 
+export function applyWorkspaceEdit(mapping: WorkspaceMapping, workspace: Workspace, edit: lsp.WorkspaceEdit, userEvent: string) {
+    for (const uri in edit.changes) {
+        const lspChanges = edit.changes[uri];
+        const file = workspace.getFile(uri);
+        if (!lspChanges.length || !file) continue;
+        workspace.updateFile(uri, {
+            changes: lspChanges.map(change => ({
+                from: mapping.mapPosition(uri, change.range.start),
+                to: mapping.mapPosition(uri, change.range.end),
+                insert: change.newText,
+            })),
+            userEvent,
+        })
+    }
+}
+
 // Public helper: attempt to create an LSP extension for `filePath`.
 // Returns an empty array (no-op extension) on failure so callers can safely
 // reconfigure their compartments with the returned value.

src/app/lsp/codeaction.ts

@@ -0,0 +1,88 @@
+import * as lsp from "vscode-languageserver-protocol";
+import { StateEffect, StateField } from "@codemirror/state";
+import { GutterMarker, ViewPlugin, ViewUpdate } from "@codemirror/view";
+import { LSPPlugin, LSPClientExtension } from "@codemirror/lsp-client";
+
+type GutterCodeAction = {
+    
+}
+
+const codeActionGutterMarker = new class extends GutterMarker {
+    toDOM() { return document.createTextNode("💡"); }
+};
+
+const codeActionGutterEffect = StateEffect.define<lsp.CodeAction[]>();
+
+const codeActionGutterState = StateField.define<lsp.CodeAction[]>({
+    create() { return []; },
+    update(updateCodeActions, tr) {
+        for (let e of tr.effects) {
+            if (e.is(codeActionGutterEffect)) {
+                return e.value;
+            }
+        }
+        return updateCodeActions;
+    }
+});
+
+const syncCodeAction = ViewPlugin.fromClass(
+    class {
+        pending: any | null = null;
+        update(update: ViewUpdate) {
+            if (update.docChanged) {
+                if (this.pending != null) clearTimeout(this.pending);
+                this.pending = setTimeout(() => {
+                    this.pending = null;
+                    const plugin = LSPPlugin.get(update.view);
+                    if (plugin) {
+                        plugin.client.sync();
+                        updateCodeActions(plugin);
+                    }
+                }, 500);
+            }
+        }
+        destroy() {
+            if (this.pending != null) clearTimeout(this.pending);
+        }
+    },
+);
+
+function updateCodeActions(plugin: LSPPlugin) {
+    const hasCap = plugin.client.serverCapabilities ? !!plugin.client.serverCapabilities["codeActionProvider"] : null;
+    if (hasCap === false) return Promise.resolve(null);
+    const params: lsp.CodeActionParams = {
+        textDocument: { uri: plugin.uri },
+        range: {
+            start: plugin.toPosition(0),
+            end: plugin.toPosition(plugin.syncedDoc.length),
+        },
+        context: {
+            diagnostics: [], // TODO fix
+            triggerKind: lsp.CodeActionTriggerKind.Automatic,
+        }
+    }
+    plugin.client.request<
+        lsp.CodeActionParams,
+        (lsp.Command | lsp.CodeAction)[]
+    >(
+        "textDocument/codeAction",
+        params
+    ).then((actions) => {
+        const file = plugin.client.workspace.getFile(plugin.uri) as OpenFile;
+        if (!file) return false;
+        if ()
+        
+    });
+}
+
+export function codeAction(config: {}): LSPClientExtension {
+    return {
+        clientCapabilities: {
+            codeAction: {
+                dataSupport: true,
+                resolveSupport: ["edit"],
+            }
+        },
+        editorExtension: syncCodeAction,
+    }
+}

src/app/lsp/diagnostics.ts

@@ -1,8 +1,55 @@
-import type * as lsp from "vscode-languageserver-protocol";
-import { ViewPlugin, ViewUpdate } from "@codemirror/view";
+import * as lsp from "vscode-languageserver-protocol";
+import { StateField, StateEffect } from "@codemirror/state";
+import { showPanel, EditorView, ViewPlugin, ViewUpdate } from "@codemirror/view";
 import { LSPPlugin, LSPClientExtension } from "@codemirror/lsp-client";
 import { OpenFile } from "../filestate";
 import { Text } from "@codemirror/state";
+import { applyWorkspaceEdit } from "../lsp";
+
+import van from "vanjs-core";
+const v = van.tags;
+
+type CodeAction = (lsp.CodeAction | lsp.Command);
+
+const setCodeActions = StateEffect.define<CodeAction[]>();
+
+const codeActionState = StateField.define<CodeAction[]>({
+    create: () => null,
+    update(value, tr) {
+        for (let e of tr.effects) {
+            if (e.is(setCodeActions)) value = e.value;
+        }
+        return value;
+    },
+    provide: f => showPanel.from(f, ca => ca ? createCodeActionPanel : null),
+});
+
+function createCodeActionPanel(view: EditorView) {
+    const plugin = LSPPlugin.get(view);
+    const actions = view.state.field(codeActionState);
+    const mapping = plugin.client.workspaceMapping();
+    // TODO cleanup mapping when done
+    // TODO use codemirror/view.showDialog instead
+    const list = v.ul(actions.map(a => {
+        if (!Object.hasOwn(a, "edit")) return null;
+        const action = a as lsp.CodeAction;
+        // TODO action resolving
+        const onclick = () => {
+            applyWorkspaceEdit(mapping, plugin.client.workspace, action.edit, "codeaction");
+            view.dispatch({effects: setCodeActions.of(null)});
+        }
+        return v.li(v.a({onclick}, action.title));
+    }));
+    const closeBtn = v.button({
+        class: "absolute top-0 right-5",
+        type: "button",
+        name: "close",
+        "aria-label": view.state.phrase("close"),
+        onclick: () => view.dispatch({effects: setCodeActions.of(null)}),
+    }, "×");
+    const dom = v.div(list, closeBtn);
+    return { top: false, dom };
+}
 
 function toSeverity(sev: lsp.DiagnosticSeverity) {
     return sev == 1
@@ -38,6 +85,26 @@ function fromPosition(doc: Text, pos: lsp.Position): number {
     return line.from + pos.character;
 }
 
+function fetchCodeActionsForDiagnostic(plugin: LSPPlugin, diag: lsp.Diagnostic): Promise<CodeAction[]> {
+    const hasCap = plugin.client.serverCapabilities ? !!plugin.client.serverCapabilities["codeActionProvider"] : null;
+    if (hasCap === false) return Promise.resolve(null);
+    const params: lsp.CodeActionParams = {
+        textDocument: { uri: plugin.uri },
+        range: diag.range,
+        context: {
+            diagnostics: [diag], // TODO multiple?
+            triggerKind: lsp.CodeActionTriggerKind.Invoked,
+        }
+    }
+    return plugin.client.request<
+        lsp.CodeActionParams,
+        (lsp.Command | lsp.CodeAction)[]
+    >(
+        "textDocument/codeAction",
+        params
+    );
+}
+
 export function serverDiagnostics(): LSPClientExtension {
     return {
         clientCapabilities: {
@@ -55,6 +122,7 @@ export function serverDiagnostics(): LSPClientExtension {
                 if (params.version != null && params.version != file.version) {
                     return false;
                 }
+
                 file.setDiagnostics(
                     params.diagnostics.map((item) => ({
                         from: file.changes.mapPos(
@@ -65,11 +133,20 @@ export function serverDiagnostics(): LSPClientExtension {
                         ),
                         severity: toSeverity(item.severity ?? 1),
                         message: item.message,
+                        actions: [{
+                            name: "Solve",
+                            apply: async (view) => {
+                                const plugin = LSPPlugin.get(view);
+                                const a = await fetchCodeActionsForDiagnostic(plugin, item);
+                                const effects = setCodeActions.of(a);
+                                view.dispatch({ effects });
+                            },
+                        }]
                     })),
                 );
                 return true;
             },
         },
-        editorExtension: autoSync,
+        editorExtension: [autoSync, codeActionState],
     };
 }

src/main/langserver.ts

@@ -19,6 +19,9 @@ const lspServers = new Map<string, LspEntry>();
 const fallbackServerForLanguage: Record<string, string | undefined> = {
     typescript: "npx typescript-language-server --log-level 4 --stdio",
     python: "pylsp --check-parent-process",
+    haskell: "haskell-language-server-wrapper --lsp",
+    rust: "rust-analyzer",
+    cpp: "clangd",
 };
 
 function ensureLspForKey(