feat(facade): add RegExpWrapper.replaceAll to replace all matches using the provided function

Author: vsavkin

modules/angular2/src/facade/lang.dart

@@ -215,6 +215,20 @@ class RegExpWrapper {
   static Iterator<Match> matcher(RegExp regExp, String input) {
     return regExp.allMatches(input).iterator;
   }
+
+  static String replaceAll(RegExp regExp, String input, Function replace) {
+    final m = RegExpWrapper.matcher(regExp, input);
+    var res = "";
+    var prev = 0;
+    while(m.moveNext()) {
+      var c = m.current;
+      res += input.substring(prev, c.start);
+      res += replace(c);
+      prev = c.start + c[0].length;
+    }
+    res += input.substring(prev);
+    return res;
+  }
 }
 
 class RegExpMatcherWrapper {

modules/angular2/src/facade/lang.ts

@@ -347,6 +347,21 @@ export class RegExpWrapper {
     regExp.lastIndex = 0;
     return {re: regExp, input: input};
   }
+  static replaceAll(regExp: RegExp, input: string, replace: Function): string {
+    let c = regExp.exec(input);
+    let res = '';
+    regExp.lastIndex = 0;
+    let prev = 0;
+    while (c) {
+      res += input.substring(prev, c.index);
+      res += replace(c);
+      prev = c.index + c[0].length;
+      regExp.lastIndex = prev;
+      c = regExp.exec(input);
+    }
+    res += input.substring(prev);
+    return res;
+  }
 }
 
 export class RegExpMatcherWrapper {

modules/angular2/test/facade/lang_spec.ts

@@ -42,6 +42,12 @@ export function main() {
       // If not reset, the second attempt to test results in false
       expect(RegExpWrapper.test(re, str)).toEqual(true);
     });
+
+    it("should implement replace all", () => {
+      let re = /(\d)+/g;
+      let m = RegExpWrapper.replaceAll(re, 'a1b2c', (match) => `!${match[1]}!`);
+      expect(m).toEqual('a!1!b!2!c');
+    });
   });
 
   describe('const', () => {