fix(filters): Fix filters in the code-gen parser

Author: jbdeboer

bin/parser_generator_for_spec.dart

@@ -200,6 +200,10 @@ main(arguments) {
       'returnTrue() ? returnString() : returnInt()',
       'returnFalse() ? returnString() : returnInt()',
       'identity(returnFalse() ? returnString() : returnInt())',
-      "taxRate ~/ 100 * subTotal"
+      "taxRate ~/ 100 * subTotal",
+      "'fOo'|uppercase|lowercase",
+      "n = (name|lowercase)",
+      "n",
+      "1|nonexistent"
   ]);
 }

lib/tools/parser_generator/dart_code_gen.dart

@@ -19,7 +19,7 @@ class Code implements ParserAST {
 
   get exp {
     if (_exp == null) {
-      throw "Can not be used in an expression";
+      throw "Can not be used in an expression: $id";
     }
     return _exp;
   }
@@ -58,29 +58,6 @@ class MultipleStatementCode extends Code {
   }
 }
 
-class FilterCode extends Code {
-  final String filterName;
-  final Code leftHandSide;
-  final List<Code> parameters;
-  final Function evalError;
-
-  FilterCode(String this.filterName,
-             Code this.leftHandSide,
-             List<Code> this.parameters,
-             Function this.evalError): super(null);
-
-  get id => '${leftHandSide.id} | $filterName:${parameters.map((e)=>e.id).join(':')}}';
-
-  Source toSource(SourceBuilder _) {
-    var params = parameters.map((e) => _.ref(e));
-    return _('new FilterExpression', _.parens(
-      'filters(${_.str(filterName)})',
-      _.ref(leftHandSide),
-      '[${params.join(', ')}]'
-    ));
-  }
-}
-
 escape(String s) => s.replaceAll('\'', '\\\'').replaceAll(r'$', r'\$');
 
 class GetterSetterGenerator {
@@ -314,6 +291,9 @@ class DartCodeGen implements ParserBackend {
               Code leftHandSide,
               List<Code> parameters,
               Function evalError) {
-    return new FilterCode(filterName, leftHandSide, parameters, evalError);
+    return new Code(
+        'filters(\'${filterName}\')(${
+            ([leftHandSide]..addAll(parameters))
+              .map((Code p) => p.exp).join(', ')})');
   }
 }

test/core/parser/parser_spec.dart

@@ -821,11 +821,6 @@ main() {
         expect(eval("'fOo'|uppercase|lowercase")).toEqual("foo");
       });
 
-      it('Compiled filter should be instace of FilterExpression', () {
-        var expression = parser("'Foo'|uppercase");
-        expect(expression is FilterExpression).toEqual(true);
-      });
-
       it('should call a filter with arguments', () {
         expect(eval("1|increment:2")).toEqual(3);
       });