Binary left and right shift operators, expressions and implementation

ajlopez · Dec 14, 2014 · ee368e4 · ee368e4
1 parent 5b10448
commit ee368e4
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Showing 3 changed files with 34 additions and 2 deletions.
diff --git a/lib/expressions.js b/lib/expressions.js
@@ -573,6 +573,18 @@ function BinaryXorExpression(left, right) {
     };
 }
 
+function BinaryLeftShiftExpression(left, right) {
+    this.evaluate = function (context) {
+        return left.evaluate(context) << right.evaluate(context);
+    };
+}
+
+function BinaryRightShiftExpression(left, right) {
+    this.evaluate = function (context) {
+        return left.evaluate(context) >> right.evaluate(context);
+    };
+}
+
 function BinaryNotExpression(expr) {
     this.evaluate = function (context) {
         return ~expr.evaluate(context);
@@ -622,6 +634,8 @@ module.exports = {
     BinaryOrExpression: BinaryOrExpression,
     BinaryXorExpression: BinaryXorExpression,
     BinaryNotExpression: BinaryNotExpression,
+    BinaryLeftShiftExpression: BinaryLeftShiftExpression,
+    BinaryRightShiftExpression: BinaryRightShiftExpression,
     LogicalAndExpression: LogicalAndExpression,
     LogicalOrExpression: LogicalOrExpression
 };

diff --git a/lib/parsers.js b/lib/parsers.js
@@ -47,6 +47,8 @@ var ClassExpression = expressions.ClassExpression,
     BinaryOrExpression = expressions.BinaryOrExpression,
     BinaryXorExpression = expressions.BinaryXorExpression,
     BinaryNotExpression = expressions.BinaryNotExpression,
+    BinaryLeftShiftExpression = expressions.BinaryLeftShiftExpression,
+    BinaryRightShiftExpression = expressions.BinaryRightShiftExpression,
     LogicalAndExpression = expressions.LogicalAndExpression,
     LogicalOrExpression = expressions.LogicalOrExpression;
 
@@ -83,10 +85,10 @@ var rules = [
     get('!=').generate('NotEqual'),
     get('<=>').generate('LessEqualGreater'),
     get('<=').generate('LessEqual'),
-    get('<<').generate('LessLess'),
+    get('<<').generate('BinaryLeftShift'),
     get('<').generate('Less'),
     get('>=').generate('GreaterEqual'),
-    get('>>').generate('GreaterGreater'),
+    get('>>').generate('BinaryRightShift'),
     get('>').generate('Greater'),
     get('=').generate('Assign'),
     get('&&').generate('LogicalAnd'),
@@ -198,6 +200,8 @@ var rules = [
     get('Expression2', 'BinaryAnd', 'Expression1').generate('Expression2', function (values) { return new BinaryAndExpression(values[0], values[2]); }),
     get('Expression2', 'BinaryOr', 'Expression1').generate('Expression2', function (values) { return new BinaryOrExpression(values[0], values[2]); }),
     get('Expression2', 'BinaryXor', 'Expression1').generate('Expression2', function (values) { return new BinaryXorExpression(values[0], values[2]); }),
+    get('Expression2', 'BinaryLeftShift', 'Expression1').generate('Expression2', function (values) { return new BinaryLeftShiftExpression(values[0], values[2]); }),
+    get('Expression2', 'BinaryRightShift', 'Expression1').generate('Expression2', function (values) { return new BinaryRightShiftExpression(values[0], values[2]); }),
 
     // Skip initial end of lines in Expression
     //get(get('\n').oneOrMore(), 'Expression').generate('Expression', function (values) { return values[1] }),

diff --git a/test/evaluate.js b/test/evaluate.js
@@ -74,6 +74,20 @@ exports['Evaluate binary xor'] = function (test) {
     test.strictEqual(result, 15 ^ 2);
 };
 
+exports['Evaluate binary left shift'] = function (test) {
+    var result = evaluate("15 << 2", "Expression", null, test);
+
+    test.ok(result);
+    test.strictEqual(result, 15 << 2);
+};
+
+exports['Evaluate binary right shift'] = function (test) {
+    var result = evaluate("15 >> 2", "Expression", null, test);
+
+    test.ok(result);
+    test.strictEqual(result, 15 >> 2);
+};
+
 exports['Evaluate binary not'] = function (test) {
     var result = evaluate("~15", "Expression", null, test);