refactor(NumberPipe): remove NumberPipe and replace it with private helper function

NumberPipe was just an implementation detail that we were accidentaly exposing as a public api.

modules/@angular/common/src/pipes.ts

@@ -9,7 +9,7 @@ export {DatePipe} from './pipes/date_pipe';
 export {JsonPipe} from './pipes/json_pipe';
 export {SlicePipe} from './pipes/slice_pipe';
 export {LowerCasePipe} from './pipes/lowercase_pipe';
-export {NumberPipe, DecimalPipe, PercentPipe, CurrencyPipe} from './pipes/number_pipe';
+export {DecimalPipe, PercentPipe, CurrencyPipe} from './pipes/number_pipe';
 export {UpperCasePipe} from './pipes/uppercase_pipe';
 export {ReplacePipe} from './pipes/replace_pipe';
 export {I18nPluralPipe} from './pipes/i18n_plural_pipe';

modules/@angular/common/src/pipes/number_pipe.ts

@@ -6,27 +6,23 @@ import {
   isBlank,
   NumberWrapper,
   RegExpWrapper,
+  Type
 } from '../../src/facade/lang';
 import {BaseException} from '../../src/facade/exceptions';
 import {NumberFormatter, NumberFormatStyle} from '../../src/facade/intl';
-import {ListWrapper} from '../../src/facade/collection';
-
 import {InvalidPipeArgumentException} from './invalid_pipe_argument_exception';
 
 var defaultLocale: string = 'en-US';
 var _re = RegExpWrapper.create('^(\\d+)?\\.((\\d+)(\\-(\\d+))?)?$');
 
 /**
- * Internal base class for numeric pipes.
+ * Internal function to format numbers used by Decimal, Percent and Date pipes.
  */
-@Injectable()
-export class NumberPipe {
-  /** @internal */
-  static _format(value: number, style: NumberFormatStyle, digits: string, currency: string = null,
+function formatNumber(pipe: Type, value: number, style: NumberFormatStyle, digits: string, currency: string = null,
                  currencyAsSymbol: boolean = false): string {
   if (isBlank(value)) return null;
   if (!isNumber(value)) {
-      throw new InvalidPipeArgumentException(NumberPipe, value);
+    throw new InvalidPipeArgumentException(pipe, value);
   }
   var minInt = 1, minFraction = 0, maxFraction = 3;
   if (isPresent(digits)) {
@@ -51,12 +47,12 @@ export class NumberPipe {
     currency: currency,
     currencyAsSymbol: currencyAsSymbol
   });
-  }
 }
 
 /**
  * WARNING: this pipe uses the Internationalization API.
- * Therefore it is only reliable in Chrome and Opera browsers.
+ * Therefore it is only reliable in Chrome and Opera browsers. For other browsers please use an
+ * polyfill, for example: [https://github.com/andyearnshaw/Intl.js/].
  *
  * Formats a number as local text. i.e. group sizing and separator and other locale-specific
  * configurations are based on the active locale.
@@ -79,18 +75,20 @@ export class NumberPipe {
  * ### Example
  *
  * {@example core/pipes/ts/number_pipe/number_pipe_example.ts region='NumberPipe'}
+ *
+ * @experimental
  */
 @Pipe({name: 'number'})
-@Injectable()
-export class DecimalPipe extends NumberPipe implements PipeTransform {
+export class DecimalPipe implements PipeTransform {
   transform(value: any, digits: string = null): string {
-    return NumberPipe._format(value, NumberFormatStyle.Decimal, digits);
+    return formatNumber(DecimalPipe, value, NumberFormatStyle.Decimal, digits);
   }
 }
 
 /**
  * WARNING: this pipe uses the Internationalization API.
- * Therefore it is only reliable in Chrome and Opera browsers.
+ * Therefore it is only reliable in Chrome and Opera browsers. For other browsers please use an
+ * polyfill, for example: [https://github.com/andyearnshaw/Intl.js/].
  *
  * Formats a number as local percent.
  *
@@ -103,18 +101,21 @@ export class DecimalPipe extends NumberPipe implements PipeTransform {
  * ### Example
  *
  * {@example core/pipes/ts/number_pipe/number_pipe_example.ts region='PercentPipe'}
+ *
+ * @experimental
  */
 @Pipe({name: 'percent'})
-@Injectable()
-export class PercentPipe extends NumberPipe implements PipeTransform {
+export class PercentPipe implements PipeTransform {
   transform(value: any, digits: string = null): string {
-    return NumberPipe._format(value, NumberFormatStyle.Percent, digits);
+    return formatNumber(PercentPipe, value, NumberFormatStyle.Percent, digits);
   }
 }
 
 /**
  * WARNING: this pipe uses the Internationalization API.
- * Therefore it is only reliable in Chrome and Opera browsers.
+ * Therefore it is only reliable in Chrome and Opera browsers. For other browsers please use an
+ * polyfill, for example: [https://github.com/andyearnshaw/Intl.js/].
+ *
  *
  * Formats a number as local currency.
  *
@@ -131,13 +132,14 @@ export class PercentPipe extends NumberPipe implements PipeTransform {
  * ### Example
  *
  * {@example core/pipes/ts/number_pipe/number_pipe_example.ts region='CurrencyPipe'}
+ *
+ * @experimental
  */
 @Pipe({name: 'currency'})
-@Injectable()
-export class CurrencyPipe extends NumberPipe implements PipeTransform {
+export class CurrencyPipe implements PipeTransform {
   transform(value: any, currencyCode: string = 'USD', symbolDisplay: boolean = false,
             digits: string = null): string {
-    return NumberPipe._format(value, NumberFormatStyle.Currency, digits, currencyCode,
+    return formatNumber(CurrencyPipe, value, NumberFormatStyle.Currency, digits, currencyCode,
                               symbolDisplay);
   }
 }

modules/@angular/integration_test/public_api_spec.ts

@@ -82,7 +82,6 @@ var COMMON: string[] = [
   'NgSwitch',
   'NgSwitchWhen',
   'NgSwitchDefault',
-  'NumberPipe',
   'ObservableListDiff:dart',
   'ObservableListDiffFactory:dart',
   'PatternValidator',