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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
export type Token = {  type: string;  value: string | number;  index: number;  [key: string]: unknown;};
export interface ReceiverResult {  [name: string]: string | number | unknown;}export type CallbackResult = {  type: string;  value: string | number;  [key: string]: unknown;};type CallbackFunction = (value: unknown) => CallbackResult;
export type TestResult = { value: unknown; length: number } | undefined;export type TestFunction = (  string: string,) => TestResult | undefined;
export interface Rule {  test: TestFunction;  fn: CallbackFunction;}
export class Tokenizer {  rules: Rule[];
  constructor(rules: Rule[] = []) {    this.rules = rules;  }
  addRule(test: TestFunction, fn: CallbackFunction): Tokenizer {    this.rules.push({ test, fn });    return this;  }
  tokenize(    string: string,    receiver = (token: Token): ReceiverResult => token,  ): ReceiverResult[] {    function* generator(rules: Rule[]): IterableIterator<ReceiverResult> {      let index = 0;      for (const rule of rules) {        const result = rule.test(string);        if (result) {          const { value, length } = result;          index += length;          string = string.slice(length);          const token = { ...rule.fn(value), index };          yield receiver(token);          yield* generator(rules);        }      }    }    const tokenGenerator = generator(this.rules);
    const tokens: ReceiverResult[] = [];
    for (const token of tokenGenerator) {      tokens.push(token);    }
    if (string.length) {      throw new Error(        `parser error: string not fully parsed! ${string.slice(0, 25)}`,      );    }
    return tokens;  }}