in expression

lib/ast.js

@@ -22,6 +22,7 @@ module.exports = {
   SuperExpression: require('./ast/expressions/SuperExpression').SuperExpression,
   SplatExpression: require('./ast/expressions/SplatExpression').SplatExpression,
   ConditionalExpression: require('./ast/expressions/ConditionalExpression').ConditionalExpression,
+  InExpression: require('./ast/expressions/InExpression').InExpression,
   BlockStatement: require('./ast/statements/BlockStatement').BlockStatement,
   ExpressionStatement: require('./ast/statements/ExpressionStatement').ExpressionStatement,
   IfStatement: require('./ast/statements/IfStatement').IfStatement,

lib/ast/expressions/InExpression.js

@@ -0,0 +1,114 @@
+var Node = require('../Node').Node;
+
+exports.InExpression = function (left, right) {
+  Node.call(this);
+
+  this.type = 'InExpression';
+
+  this.left = left;
+  this.left.parent = this;
+
+  this.right = right;
+  this.right.parent = this;
+};
+
+exports.InExpression.prototype = Object.create(Node);
+
+exports.InExpression.prototype.codegen = function () {
+  if (!Node.prototype.codegen.call(this)) {
+    return;
+  }
+
+  this.left = this.left.codegen();
+  this.right = this.right.codegen();
+
+  if (this.right.hasCallExpression && this.right.hasCallExpression()) {
+    var context = this.getContext();
+
+    var id = {
+      "type": "Identifier",
+      "name": exports.InExpression.getNextVariableName(),
+      "codeGenerated": true
+    };
+
+    context.node.body.splice(context.position + 
+      (exports.InExpression.inExpressionIndex - 2), 0, {
+      "type": "VariableDeclaration",
+      "declarations": [
+        {
+          "type": "VariableDeclarator",
+          "id": id,
+          "init": this.right
+        }
+      ],
+      "kind": "var",
+      "codeGenerated": true
+    });
+
+    this.right = id;
+  }
+
+  this.type = "ConditionalExpression";
+  this.test = {
+    "type": "BinaryExpression",
+    "operator": "instanceof",
+    "left": this.right,
+    "right": {
+      "type": "Identifier",
+      "name": "Array"
+    }
+  };
+
+  this.consequent = {
+    "type": "BinaryExpression",
+    "operator": "!==",
+    "left": {
+      "type": "CallExpression",
+      "callee": {
+        "type": "MemberExpression",
+        "computed": false,
+        "object": this.right,
+        "property": {
+          "type": "Identifier",
+          "name": "indexOf"
+        }
+      },
+      "arguments": [this.left]
+    },
+    "right": {
+      "type": "UnaryExpression",
+      "operator": "-",
+      "argument": {
+        "type": "Literal",
+        "value": 1,
+        "raw": "1"
+      },
+      "prefix": true
+    }
+  };
+
+  this.alternate = {
+    "type": "BinaryExpression",
+    "operator": "in",
+    "left": this.left,
+    "right": this.right
+  };
+
+  return this;
+};
+
+exports.InExpression.prototype.hasCallExpression = function () {
+  return true;
+};
+
+exports.InExpression.getNextVariableName = function () {
+  if (!this.inExpressionIndex) { 
+    this.inExpressionIndex = 0;
+  }
+
+  return "inExpression" + this.inExpressionIndex++;
+};
+
+exports.InExpression.resetVariableNames = function () {
+  this.inExpressionIndex = 0;
+};