feat(web)!: rewrite the library in TypeScript

lib/binding_web/src/lookahead_iterator.ts

@@ -0,0 +1,50 @@
+import { C, Internal, assertInternal } from './constants';
+import { Language } from './language';
+
+export class LookaheadIterator implements Iterable<string> {
+  private [0]: number; // Internal handle for WASM
+  private language: Language;
+
+  constructor(internal: Internal, address: number, language: Language) {
+    assertInternal(internal);
+    this[0] = address;
+    this.language = language;
+  }
+
+  get currentTypeId(): number {
+    return C._ts_lookahead_iterator_current_symbol(this[0]);
+  }
+
+  get currentType(): string {
+    return this.language.types[this.currentTypeId] || 'ERROR';
+  }
+
+  delete(): void {
+    C._ts_lookahead_iterator_delete(this[0]);
+    this[0] = 0;
+  }
+
+  resetState(stateId: number): boolean {
+    return Boolean(C._ts_lookahead_iterator_reset_state(this[0], stateId));
+  }
+
+  reset(language: Language, stateId: number): boolean {
+    if (C._ts_lookahead_iterator_reset(this[0], language[0], stateId)) {
+      this.language = language;
+      return true;
+    }
+    return false;
+  }
+
+  [Symbol.iterator](): Iterator<string> {
+    const self = this;
+    return {
+      next(): IteratorResult<string> {
+        if (C._ts_lookahead_iterator_next(self[0])) {
+          return { done: false, value: self.currentType };
+        }
+        return { done: true, value: '' };
+      }
+    };
+  }
+}