angular-docs-cn/modules/angular2/src/facade/lang.ts

var _global: BrowserNodeGlobal = <any>(typeof window === 'undefined' ? global : window);
export {_global as global};

export var Type = Function;
export type Type = new (... args: any[]) => any;

export class BaseException extends Error {
  message;
  stack;
  constructor(message?: string) {
    super(message);
    this.message = message;
    this.stack = (<any>new Error()).stack;
  }

  toString(): string { return this.message; }
}

export var Math = _global.Math;
export var Date = _global.Date;

var assertionsEnabled_ = typeof _global['assert'] !== 'undefined';
export function assertionsEnabled(): boolean {
  return assertionsEnabled_;
}

// TODO: remove calls to assert in production environment
// Note: Can't just export this and import in in other files
// as `assert` is a reserved keyword in Dart
_global.assert =
    function assert(condition) {
      if (assertionsEnabled_) {
        _global['assert'].call(condition);
      }
    }
// This function is needed only to properly support Dart's const expressions
// see https://github.com/angular/ts2dart/pull/151 for more info
export function CONST_EXPR<T>(expr: T): T {
  return expr;
}

export function CONST() {
  return (target) => target;
}

export class ABSTRACT {}

// Note: This is only a marker annotation needed for ts2dart.
// This is written so that is can be used as a Traceur annotation
// or a Typescript decorator.
export function IMPLEMENTS(_) {
  return (t) => t;
}

export function isPresent(obj): boolean {
  return obj !== undefined && obj !== null;
}

export function isBlank(obj): boolean {
  return obj === undefined || obj === null;
}

export function isString(obj): boolean {
  return typeof obj === "string";
}

export function isFunction(obj): boolean {
  return typeof obj === "function";
}

export function isType(obj): boolean {
  return isFunction(obj);
}

export function stringify(token): string {
  if (typeof token === 'string') {
    return token;
  }

  if (token === undefined || token === null) {
    return '' + token;
  }

  if (token.name) {
    return token.name;
  }

  return token.toString();
}

export class StringWrapper {
  static fromCharCode(code: int): string { return String.fromCharCode(code); }

  static charCodeAt(s: string, index: int) { return s.charCodeAt(index); }

  static split(s: string, regExp) { return s.split(regExp); }

  static equals(s: string, s2: string): boolean { return s === s2; }

  static replace(s: string, from: string, replace: string): string {
    return s.replace(from, replace);
  }

  static replaceAll(s: string, from: RegExp, replace: string): string {
    return s.replace(from, replace);
  }

  static toUpperCase(s: string): string { return s.toUpperCase(); }

  static toLowerCase(s: string): string { return s.toLowerCase(); }

  static startsWith(s: string, start: string) { return s.startsWith(start); }

  static substring(s: string, start: int, end: int = null) {
    return s.substring(start, end === null ? undefined : end);
  }

  static replaceAllMapped(s: string, from: RegExp, cb: Function): string {
    return s.replace(from, function(... matches) {
      // Remove offset & string from the result array
      matches.splice(-2, 2);
      // The callback receives match, p1, ..., pn
      return cb(matches);
    });
  }

  static contains(s: string, substr: string): boolean { return s.indexOf(substr) != -1; }
}

export class StringJoiner {
  constructor(public parts = []) {}

  add(part: string) { this.parts.push(part); }

  toString(): string { return this.parts.join(""); }
}

export class NumberParseError extends BaseException {
  name: string;

  constructor(public message: string) { super(); }

  toString() { return this.message; }
}


export class NumberWrapper {
  static toFixed(n: number, fractionDigits: int): string { return n.toFixed(fractionDigits); }

  static equal(a, b): boolean { return a === b; }

  static parseIntAutoRadix(text: string): int {
    var result: int = parseInt(text);
    if (isNaN(result)) {
      throw new NumberParseError("Invalid integer literal when parsing " + text);
    }
    return result;
  }

  static parseInt(text: string, radix: int): int {
    if (radix == 10) {
      if (/^(\-|\+)?[0-9]+$/.test(text)) {
        return parseInt(text, radix);
      }
    } else if (radix == 16) {
      if (/^(\-|\+)?[0-9ABCDEFabcdef]+$/.test(text)) {
        return parseInt(text, radix);
      }
    } else {
      var result: int = parseInt(text, radix);
      if (!isNaN(result)) {
        return result;
      }
    }
    throw new NumberParseError("Invalid integer literal when parsing " + text + " in base " +
                               radix);
  }

  // TODO: NaN is a valid literal but is returned by parseFloat to indicate an error.
  static parseFloat(text: string): number { return parseFloat(text); }

  static get NaN(): number { return NaN; }

  static isNaN(value): boolean { return isNaN(value); }

  static isInteger(value): boolean { return Number.isInteger(value); }
}

export var RegExp = _global.RegExp;

export class RegExpWrapper {
  static create(regExpStr, flags: string = ''): RegExp {
    flags = flags.replace(/g/g, '');
    return new _global.RegExp(regExpStr, flags + 'g');
  }
  static firstMatch(regExp, input) {
    // Reset multimatch regex state
    regExp.lastIndex = 0;
    return regExp.exec(input);
  }
  static matcher(regExp, input) {
    // Reset regex state for the case
    // someone did not loop over all matches
    // last time.
    regExp.lastIndex = 0;
    return {re: regExp, input: input};
  }
}

export class RegExpMatcherWrapper {
  static next(matcher) { return matcher.re.exec(matcher.input); }
}

export class FunctionWrapper {
  static apply(fn: Function, posArgs) { return fn.apply(null, posArgs); }
}

// JS has NaN !== NaN
export function looseIdentical(a, b): boolean {
  return a === b || typeof a === "number" && typeof b === "number" && isNaN(a) && isNaN(b);
}

// JS considers NaN is the same as NaN for map Key (while NaN !== NaN otherwise)
// see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map
export function getMapKey(value) {
  return value;
}

export function normalizeBlank(obj) {
  return isBlank(obj) ? null : obj;
}

export function isJsObject(o): boolean {
  return o !== null && (typeof o === "function" || typeof o === "object");
}

export function print(obj) {
  if (obj instanceof Error) {
    console.log(obj.stack);
  } else {
    console.log(obj);
  }
}

// Can't be all uppercase as our transpiler would think it is a special directive...
export class Json {
  static parse(s: string) { return _global.JSON.parse(s); }
  static stringify(data): string {
    // Dart doesn't take 3 arguments
    return _global.JSON.stringify(data, null, 2);
  }
}

export class DateWrapper {
  static fromMillis(ms) { return new Date(ms); }
  static toMillis(date: Date) { return date.getTime(); }
  static now() { return new Date(); }
  static toJson(date) { return date.toJSON(); }
}