Initial LSP implementation/vscode support

newt-vscode-lsp/src/extension.ts

@@ -0,0 +1,95 @@
+import * as vscode from "vscode";
+import { ABBREV } from "./abbrev";
+import {
+  LanguageClient,
+  LanguageClientOptions,
+  ServerOptions,
+  TransportKind
+} from 'vscode-languageclient/node';
+
+// They put this at module level for deactivate below.
+let client: LanguageClient
+
+export function activate(context: vscode.ExtensionContext) {
+  const serverModule = context.asAbsolutePath('./dist/lsp.js')
+  console.log('*** servervModule', serverModule)
+  const config = vscode.workspace.getConfiguration("newt");
+  const cmd = config.get<string | null>("lspPath");
+
+  let serverOptions: ServerOptions
+  if (cmd) {
+    serverOptions = {
+      run: { command: "node", args: [cmd], transport: TransportKind.pipe },
+      debug: { command: "node", args: [cmd], transport: TransportKind.pipe },
+    }
+  } else {
+    serverOptions = {
+      run: { module: serverModule, transport: TransportKind.ipc },
+      debug: { module: serverModule, transport: TransportKind.ipc },
+    }
+  }
+
+  const clientOptions: LanguageClientOptions = {
+    documentSelector: [{ scheme: 'file', language: 'newt' }],
+    synchronize: {
+      fileEvents: vscode.workspace.createFileSystemWatcher('*.newt')
+    }
+  }
+
+  client = new LanguageClient(
+    'NewtLanguageServer',
+    'Newt Language Server',
+    serverOptions,
+    clientOptions
+  )
+
+  client.start();
+  console.log('CLIENT started')
+
+  vscode.workspace.onDidChangeTextDocument((event) => {
+    const editor = vscode.window.activeTextEditor;
+    if (!editor || event.document !== editor.document) return;
+
+    const changes = event.contentChanges;
+    if (changes.length === 0) return;
+
+    // TODO - agda input mode does the replacement as soon as possible
+    // but if the sequence is a prefix, it will change for subsequent characters
+    // The latter would require keeping state, but if we don't allow sequences to prefix
+    // each other, we could activate quicker.
+    const lastChange = changes[changes.length - 1];
+    const text = lastChange.text;
+    // Check if the last change is a potential shortcut trigger
+    if (!text || !(" ')\\_".includes(text) || text.startsWith('\n'))) return;
+
+    const document = editor.document;
+    const position = lastChange.range.end;
+    const lineText = document.lineAt(position.line).text;
+    const start = Math.max(0, position.character - 10);
+    const snippet = lineText.slice(start, position.character);
+    const m = snippet.match(/(\\[^ ]+)$/);
+    if (m) {
+      const cand = m[0];
+      console.log("cand", cand);
+      const replacement = ABBREV[cand];
+      console.log("repl", replacement);
+      if (replacement) {
+        const range = new vscode.Range(
+          position.line,
+          position.character - cand.length,
+          position.line,
+          position.character
+        );
+        editor.edit((editBuilder) => {
+          editBuilder.replace(range, replacement);
+        });
+      }
+    }
+  });
+  return;
+
+}
+
+export function deactivate() {
+  if (client) client.stop();
+}