Sort FreeVariables slice (#148)

* sort FreeVariables slice

* regenerate the standard library AST

ast/util.go

@@ -1,7 +1,41 @@
+/*
+Copyright 2016 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package ast
 
+import "sort"
+
 func (i *IdentifierSet) Append(idents Identifiers) {
 	for _, ident := range idents {
 		i.Add(ident)
 	}
 }
+
+// ToOrderedSlice returns the elements of the current set as a ordered slice
+func (set IdentifierSet) ToOrderedSlice() []Identifier {
+	var s []Identifier
+	for v := range set {
+		s = append(s, v)
+	}
+	sort.Sort(identifierSorter(s))
+	return s
+}
+
+type identifierSorter []Identifier
+
+func (s identifierSorter) Len() int           { return len(s) }
+func (s identifierSorter) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s identifierSorter) Less(i, j int) bool { return s[i] < s[j] }

static_analyzer.go

@@ -145,7 +145,7 @@ func analyzeVisit(a ast.Node, inObject bool, vars ast.IdentifierSet) error {
 	default:
 		panic(fmt.Sprintf("Unexpected node %#v", a))
 	}
-	a.SetFreeVariables(s.freeVars.ToSlice())
+	a.SetFreeVariables(s.freeVars.ToOrderedSlice())
 	return s.err
 }