docs/attachments/LUCENE-5754/LUCENE-5754.patch

Index: lucene/expressions/src/java/org/apache/lucene/expressions/js/Javascript.g
===================================================================
--- lucene/expressions/src/java/org/apache/lucene/expressions/js/Javascript.g	(revision 1602068)
+++ lucene/expressions/src/java/org/apache/lucene/expressions/js/Javascript.g	(working copy)
@@ -336,7 +336,7 @@
 
 fragment
 ID
-    : ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*
+    : ('a'..'z'|'A'..'Z'|'_'|'$') ('a'..'z'|'A'..'Z'|'0'..'9'|'_'|'$')*
     ;
 
 WS
Index: lucene/expressions/src/java/org/apache/lucene/expressions/js/JavascriptLexer.java
===================================================================
--- lucene/expressions/src/java/org/apache/lucene/expressions/js/JavascriptLexer.java	(revision 1602068)
+++ lucene/expressions/src/java/org/apache/lucene/expressions/js/JavascriptLexer.java	(working copy)
@@ -679,10 +679,10 @@
   // $ANTLR start "ID"
   public final void mID() throws RecognitionException {
     try {
-      // src/java/org/apache/lucene/expressions/js/Javascript.g:340:5: ( ( 'a' .. 'z' | 'A' .. 'Z' | '_' ) ( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' )* )
-      // src/java/org/apache/lucene/expressions/js/Javascript.g:340:7: ( 'a' .. 'z' | 'A' .. 'Z' | '_' ) ( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' )*
+      // src/java/org/apache/lucene/expressions/js/Javascript.g:340:5: ( ( 'a' .. 'z' | 'A' .. 'Z' | '_' | '$' ) ( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' | '$' )* )
+      // src/java/org/apache/lucene/expressions/js/Javascript.g:340:7: ( 'a' .. 'z' | 'A' .. 'Z' | '_' | '$' ) ( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' | '$' )*
       {
-      if ( (input.LA(1) >= 'A' && input.LA(1) <= 'Z')||input.LA(1)=='_'||(input.LA(1) >= 'a' && input.LA(1) <= 'z') ) {
+      if ( input.LA(1)=='$'||(input.LA(1) >= 'A' && input.LA(1) <= 'Z')||input.LA(1)=='_'||(input.LA(1) >= 'a' && input.LA(1) <= 'z') ) {
         input.consume();
       }
       else {
@@ -690,12 +690,12 @@
         recover(mse);
         throw mse;
       }
-      // src/java/org/apache/lucene/expressions/js/Javascript.g:340:31: ( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' )*
+      // src/java/org/apache/lucene/expressions/js/Javascript.g:340:35: ( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' | '$' )*
       loop2:
       while (true) {
         int alt2=2;
         int LA2_0 = input.LA(1);
-        if ( ((LA2_0 >= '0' && LA2_0 <= '9')||(LA2_0 >= 'A' && LA2_0 <= 'Z')||LA2_0=='_'||(LA2_0 >= 'a' && LA2_0 <= 'z')) ) {
+        if ( (LA2_0=='$'||(LA2_0 >= '0' && LA2_0 <= '9')||(LA2_0 >= 'A' && LA2_0 <= 'Z')||LA2_0=='_'||(LA2_0 >= 'a' && LA2_0 <= 'z')) ) {
           alt2=1;
         }
 
@@ -703,7 +703,7 @@
         case 1 :
           // src/java/org/apache/lucene/expressions/js/Javascript.g:
           {
-          if ( (input.LA(1) >= '0' && input.LA(1) <= '9')||(input.LA(1) >= 'A' && input.LA(1) <= 'Z')||input.LA(1)=='_'||(input.LA(1) >= 'a' && input.LA(1) <= 'z') ) {
+          if ( input.LA(1)=='$'||(input.LA(1) >= '0' && input.LA(1) <= '9')||(input.LA(1) >= 'A' && input.LA(1) <= 'Z')||input.LA(1)=='_'||(input.LA(1) >= 'a' && input.LA(1) <= 'z') ) {
             input.consume();
           }
           else {
@@ -1476,6 +1476,7 @@
       alt17=27;
       }
       break;
+    case '$':
     case 'A':
     case 'B':
     case 'C':
Index: lucene/expressions/src/java/org/apache/lucene/expressions/js/JavascriptParser.java
===================================================================
--- lucene/expressions/src/java/org/apache/lucene/expressions/js/JavascriptParser.java	(revision 1602068)
+++ lucene/expressions/src/java/org/apache/lucene/expressions/js/JavascriptParser.java	(working copy)
@@ -1571,7 +1571,7 @@
 
           stream_arguments.add(arguments48.getTree());
           // AST REWRITE
-          // elements: NAMESPACE_ID, arguments
+          // elements: arguments, NAMESPACE_ID
           // token labels: 
           // rule labels: retval
           // token list labels: 
Index: lucene/expressions/src/test/org/apache/lucene/expressions/TestDemoExpressions.java
===================================================================
--- lucene/expressions/src/test/org/apache/lucene/expressions/TestDemoExpressions.java	(revision 1602068)
+++ lucene/expressions/src/test/org/apache/lucene/expressions/TestDemoExpressions.java	(working copy)
@@ -136,6 +136,25 @@
     }
   }
   
+  /** Uses variables with $ */
+  public void testDollarVariable() throws Exception {
+    Expression expr = JavascriptCompiler.compile("$0+$score");
+    
+    SimpleBindings bindings = new SimpleBindings();    
+    bindings.add(new SortField("$0", SortField.Type.SCORE));
+    bindings.add(new SortField("$score", SortField.Type.SCORE));
+    
+    Sort sort = new Sort(expr.getSortField(bindings, true));
+    Query query = new TermQuery(new Term("body", "contents"));
+    TopFieldDocs td = searcher.search(query, null, 3, sort, true, true);
+    for (int i = 0; i < 3; i++) {
+      FieldDoc d = (FieldDoc) td.scoreDocs[i];
+      float expected = 2*d.score;
+      float actual = ((Double)d.fields[0]).floatValue();
+      assertEquals(expected, actual, CheckHits.explainToleranceDelta(expected, actual));
+    }
+  }
+  
   /** tests expression referring to another expression */
   public void testExpressionRefersToExpression() throws Exception {
     Expression expr1 = JavascriptCompiler.compile("_score");