/IronPython_Main/Languages/IronPython/IronPython/Compiler/Ast/GeneratorExpression.cs

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 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Apache License, Version 2.0. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Apache License, Version 2.0, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Apache License, Version 2.0.

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 * You must not remove this notice, or any other, from this software.

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#if !CLR2

using MSAst = System.Linq.Expressions;

#else

using MSAst = Microsoft.Scripting.Ast;

#endif



using System;

using System.Diagnostics;



using Microsoft.Scripting.Actions;



using IronPython.Runtime;

using IronPython.Runtime.Binding;



namespace IronPython.Compiler.Ast {

    using Ast = MSAst.Expression;



    public class GeneratorExpression : Expression {

        private readonly FunctionDefinition _function;

        private readonly Expression _iterable;



        public GeneratorExpression(FunctionDefinition function, Expression iterable) {

            _function = function;

            _iterable = iterable;

        }



        public override MSAst.Expression Reduce() {

            return Ast.Call(

                AstMethods.MakeGeneratorExpression,

                _function.MakeFunctionExpression(),

                _iterable

            );

        }



        public FunctionDefinition Function {

            get {

                return _function;

            }

        }



        public Expression Iterable {

            get {

                return _iterable;

            }

        }



        internal override string CheckAssign() {

            return "can't assign to generator expression";

        }



        internal override string CheckAugmentedAssign() {

            return CheckAssign();

        }



        internal override string CheckDelete() {

            return "can't delete generator expression";

        }



        public override void Walk(PythonWalker walker) {

            if (walker.Walk(this)) {

                _function.Walk(walker);

                _iterable.Walk(walker);

            }

            walker.PostWalk(this);

        }

    }

}