/DLR_Main/Languages/Ruby/Ruby/Compiler/Parser/VariableFactory.cs

/* ****************************************************************************

 *

 * 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 

 * ironruby@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.

 *

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

 *

 *

 * ***************************************************************************/



using System.Dynamic;

using Microsoft.Scripting;

using Microsoft.Scripting.Utils;

using IronRuby.Compiler.Ast;



namespace IronRuby.Compiler {

    internal static class VariableFactory {

        public const int Identifier = 0;

        public const int Instance = 1;

        public const int Global = 2;

        public const int Constant = 3;

        public const int Class = 4;

        public const int Nil = 5;

        public const int Self = 6;

        public const int True = 7;

        public const int False = 8;

        public const int File = 9;

        public const int Line = 10;

        public const int Encoding = 11;



        internal static Expression/*!*/ MakeRead(int kind, Parser/*!*/ parser, string name, SourceSpan location) {

            switch (kind) {

                case Identifier:

                    return (Expression)parser.CurrentScope.ResolveVariable(name) ?? new MethodCall(null, name, null, null, location);



                case Instance:

                    return new InstanceVariable(name, location);



                case Global:

                    return new GlobalVariable(name, location);



                case Constant:

                    return new ConstantVariable(name, location);



                case Class:

                    return new ClassVariable(name, location);



                case Nil:

                    return Literal.Nil(location);



                case Self:

                    return new SelfReference(location);



                case True:

                    return Literal.True(location);



                case False:

                    return Literal.False(location);



                case File:

                    return new FileLiteral(location);



                case Line:

                    return Literal.Integer(parser.Tokenizer.TokenSpan.Start.Line, location);



                case Encoding:

                    return new EncodingExpression(location);

            }



            throw Assert.Unreachable;

        }



        internal static LeftValue/*!*/ MakeLeftValue(int kind, Parser/*!*/ parser, string name, SourceSpan location) {

            switch (kind) {

                case Identifier:

                    return parser.CurrentScope.ResolveOrAddVariable(name, location);



                case Instance:

                    return new InstanceVariable(name, location);



                case Global:

                    return new GlobalVariable(name, location);



                case Constant:

                    return new ConstantVariable(name, location);



                case Class:

                    return new ClassVariable(name, location);



                case Nil:

                    return parser.CannotAssignError("nil", location);

                

                case Self:

                    return parser.CannotAssignError("self", location);



                case True:

                    return parser.CannotAssignError("true", location);

                

                case False:

                    return parser.CannotAssignError("false", location);



                case File:

                    return parser.CannotAssignError("__FILE__", location);



                case Line:

                    return parser.CannotAssignError("__LINE__", location);

                

                case Encoding:

                    return parser.CannotAssignError("__ENCODING__", location);

            }

        

            return null;

        }

    }

}