feat(parser): add support for formatters

Author: vsavkin

modules/change_detection/src/parser/ast.js

@@ -1,4 +1,5 @@
-import {FIELD, toBool, autoConvertAdd} from "facade/lang";
+import {FIELD, toBool, autoConvertAdd, isBlank, FunctionWrapper, BaseException} from "facade/lang";
+import {List, ListWrapper} from "facade/collection";
 
 export class AST {
   eval(context, formatters) {
@@ -50,6 +51,28 @@ export class FieldRead extends AST {
   }
 }
 
+export class Formatter extends AST {
+  constructor(exp:AST, name:string, args:List) {
+    this.exp = exp;
+    this.name = name;
+    this.args = args;
+    this.allArgs = ListWrapper.concat([exp], args);
+  }
+
+  eval(context, formatters) {
+    var formatter = formatters[this.name];
+    if (isBlank(formatter)) {
+      throw new BaseException(`No formatter '${this.name}' found!`);
+    }
+    var evaledArgs = evalList(context, this.allArgs, formatters);
+    return FunctionWrapper.apply(formatter, evaledArgs);
+  }
+
+  visit(visitor) {
+    visitor.visitFormatter(this);
+  }
+}
+
 export class LiteralPrimitive extends AST {
   @FIELD('final value')
   constructor(value) {
@@ -128,4 +151,15 @@ export class AstVisitor {
   visitBinary(ast:Binary) {}
   visitPrefixNot(ast:PrefixNot) {}
   visitLiteralPrimitive(ast:LiteralPrimitive) {}
+  visitFormatter(ast:Formatter) {}
 }
+
+var _evalListCache = [[],[0],[0,0],[0,0,0],[0,0,0,0],[0,0,0,0,0]];
+function evalList(context, exps:List, formatters){
+  var length = exps.length;
+  var result = _evalListCache[length];
+  for (var i = 0; i < length; i++) {
+    result[i] = exps[i].eval(context, formatters);
+  }
+  return result;
+}

modules/change_detection/src/parser/parser.js

@@ -1,9 +1,18 @@
 import {FIELD, int, isBlank} from 'facade/lang';
 import {ListWrapper, List} from 'facade/collection';
-import {Lexer, EOF, Token, $PERIOD, $COLON} from './lexer';
+import {Lexer, EOF, Token, $PERIOD, $COLON, $SEMICOLON} from './lexer';
 import {ClosureMap} from './closure_map';
-import {AST, ImplicitReceiver, FieldRead, LiteralPrimitive, Expression,
-   Binary, PrefixNot, Conditional} from './ast';
+import {
+  AST,
+  ImplicitReceiver,
+  FieldRead,
+  LiteralPrimitive,
+  Expression,
+  Binary,
+  PrefixNot,
+  Conditional,
+  Formatter
+  } from './ast';
 
 var _implicitReceiver = new ImplicitReceiver();
 
@@ -70,12 +79,35 @@ class _ParseAST {
 
   parseChain():AST {
     var exprs = [];
+    var isChain = false;
     while (this.index < this.tokens.length) {
-      ListWrapper.push(exprs, this.parseConditional());
+      var expr = this.parseFormatter();
+      ListWrapper.push(exprs, expr);
+
+      while (this.optionalCharacter($SEMICOLON)) {
+        isChain = true;
+      }
+
+      if (isChain && expr instanceof Formatter) {
+        this.error('Cannot have a formatter in a chain');
+      }
     }
     return ListWrapper.first(exprs);
   }
 
+  parseFormatter() {
+    var result = this.parseExpression();
+    while (this.optionalOperator("|")) {
+      var name = this.parseIdentifier();
+      var args = ListWrapper.create();
+      while (this.optionalCharacter($COLON)) {
+        ListWrapper.push(args, this.parseExpression());
+      }
+      result = new Formatter(result, name, args);
+    }
+    return result;
+  }
+
   parseExpression() {
     return this.parseConditional();
   }

modules/change_detection/test/parser/parser_spec.js

@@ -1,4 +1,5 @@
 import {ddescribe, describe, it, iit, expect, beforeEach} from 'test_lib/test_lib';
+import {BaseException} from 'facade/lang';
 import {Parser} from 'change_detection/parser/parser';
 import {Lexer} from 'change_detection/parser/lexer';
 import {ClosureMap} from 'change_detection/parser/closure_map';
@@ -12,7 +13,7 @@ class TestData {
 
 class ContextWithErrors {
   get boo() {
-    throw new Error("boo to you");
+    throw new BaseException("boo to you");
   }
 }
 
@@ -146,10 +147,41 @@ export function main() {
         expectEval("null - null").toBeNull();
       });
     });
+
+    describe('formatters', () => {
+      beforeEach(() => {
+        formatters = {
+          "uppercase": (s) => s.toUpperCase(),
+          "lowercase": (s) => s.toLowerCase(),
+          "increment": (a,b) => a + b
+        }
+      });
+
+      it('should call a formatter', () => {
+        expectEval("'Foo'|uppercase").toEqual("FOO");
+        expectEval("'fOo'|uppercase|lowercase").toEqual("foo");
+      });
+
+      it('should call a formatter with arguments', () => {
+        expectEval("1|increment:2").toEqual(3);
+      });
+
+      it('should throw when invalid formatter', () => {
+        expectEvalError("1|nonexistent").toThrowError('No formatter \'nonexistent\' found!');
+      });;
+
+      it('should not allow formatters in a chain', () => {
+        expectEvalError("1;'World'|hello").
+            toThrowError(new RegExp('Cannot have a formatter in a chain'));
+        expectEvalError("'World'|hello;1").
+            toThrowError(new RegExp('Cannot have a formatter in a chain'));
+      });
+    });
 
     describe("error handling", () => {
       it('should throw on incorrect ternary operator syntax', () => {
-        expectEvalError("true?1").toThrowError(new RegExp('Parser Error: Conditional expression true\\?1 requires all 3 expressions'));
+        expectEvalError("true?1").
+            toThrowError(new RegExp('Parser Error: Conditional expression true\\?1 requires all 3 expressions'));
       });
 
       it('should pass exceptions', () => {

modules/facade/src/collection.dart

@@ -46,6 +46,7 @@ class ListWrapper {
   static last(List list) => list.last;
   static List reversed(List list) => list.reversed.toList();
   static void push(List l, e) { l.add(e); }
+  static List concat(List a, List b) {a.addAll(b); return a;}
 }
 
 class SetWrapper {

modules/facade/src/collection.es6

@@ -79,6 +79,7 @@ export class ListWrapper {
     var a = ListWrapper.clone(array);
     return a.reverse();
   }
+  static concat(a, b) {return a.concat(b);}
 }
 
 export class SetWrapper {

modules/facade/src/lang.dart

@@ -103,3 +103,18 @@ class RegExpMatcherWrapper {
   }
 }
 
+class FunctionWrapper {
+  static apply(Function fn, posArgs) {
+    return Function.apply(fn, posArgs);
+  }
+}
+
+class BaseException extends Error {
+  final String message;
+
+  BaseException(this.message);
+
+  String toString() {
+    return this.message;
+  }
+}

modules/facade/src/lang.es6

@@ -137,3 +137,18 @@ export class RegExpMatcherWrapper {
   }
 }
 
+export class FunctionWrapper {
+  static apply(fn:Function, posArgs) {
+    return fn.apply(null, posArgs);
+  }
+}
+
+export class BaseException extends Error {
+  constructor(message){
+    this.message = message;
+  }
+
+  toString():String {
+    return this.message;
+  }
+}