Method expect

scripts/rubi/wl-parser.ts:203–207

(value: string)

    return t;
  }
  private expect(value: string): void {
    const t = this.next();
    if (t.kind !== 'punct' || t.value !== value)
      throw new Error(`expected '${value}', got '${t.value}'`);
  }

  atEnd(): boolean {
    return this.i >= this.tokens.length;