/DICK.B1/IronPython/Runtime/Binding/PythonGetIndexBinder.cs

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

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Microsoft Public License. A 

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

 * you cannot locate the  Microsoft Public License, 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 Microsoft Public License.

 *

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

 *

 *

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



#if !CLR2

using System.Linq.Expressions;

#else

using Microsoft.Scripting.Ast;

#endif



using System;

using System.Dynamic;

using System.Reflection;

using System.Runtime.CompilerServices;



using Microsoft.Scripting.Runtime;

using Microsoft.Scripting.Utils;

using Microsoft.Scripting.Generation;



using IronPython.Runtime.Operations;



namespace IronPython.Runtime.Binding {

    using Ast = Expression;

    using AstUtils = Microsoft.Scripting.Ast.Utils;



    class PythonGetIndexBinder : GetIndexBinder, IPythonSite, IExpressionSerializable {

        private readonly PythonContext/*!*/ _context;



        public PythonGetIndexBinder(PythonContext/*!*/ context, int argCount)

            : base(new CallInfo(argCount)) {

            _context = context;

        }



        public override DynamicMetaObject FallbackGetIndex(DynamicMetaObject target, DynamicMetaObject[] indexes, DynamicMetaObject errorSuggestion) {

#if !SILVERLIGHT

            DynamicMetaObject com;

            if (Microsoft.Scripting.ComInterop.ComBinder.TryBindGetIndex(this, target, BindingHelpers.GetComArguments(indexes), out com)) {

                return com;

            }

#endif

            return PythonProtocol.Index(this, PythonIndexType.GetItem, ArrayUtils.Insert(target, indexes), errorSuggestion);

        }



        public override T BindDelegate<T>(CallSite<T> site, object[] args) {

            ParameterInfo[] prms = typeof(T).GetMethod("Invoke").GetParameters();



            if (CompilerHelpers.GetType(args[1]) == typeof(int)) {

                if (CompilerHelpers.GetType(args[0]) == typeof(List)) {

                    if (typeof(T) == typeof(Func<CallSite, object, object, object>)) {

                        return (T)(object)new Func<CallSite, object, object, object>(ListIndex);

                    } else if (typeof(T) == typeof(Func<CallSite, object, int, object>)) {

                        return (T)(object)new Func<CallSite, object, int, object>(ListIndex);

                    } else if (typeof(T) == typeof(Func<CallSite, List, object, object>)) {

                        return (T)(object)new Func<CallSite, List, object, object>(ListIndex);

                    }

                } else if (CompilerHelpers.GetType(args[0]) == typeof(PythonTuple)) {

                    if (typeof(T) == typeof(Func<CallSite, object, object, object>)) {

                        return (T)(object)new Func<CallSite, object, object, object>(TupleIndex);

                    } else if (typeof(T) == typeof(Func<CallSite, object, int, object>)) {

                        return (T)(object)new Func<CallSite, object, int, object>(TupleIndex);

                    } else if (typeof(T) == typeof(Func<CallSite, PythonTuple, object, object>)) {

                        return (T)(object)new Func<CallSite, PythonTuple, object, object>(TupleIndex);

                    }

                } else if (CompilerHelpers.GetType(args[0]) == typeof(string)) {

                    if (typeof(T) == typeof(Func<CallSite, object, object, object>)) {

                        return (T)(object)new Func<CallSite, object, object, object>(StringIndex);

                    } else if (typeof(T) == typeof(Func<CallSite, object, int, object>)) {

                        return (T)(object)new Func<CallSite, object, int, object>(StringIndex);

                    } else if (typeof(T) == typeof(Func<CallSite, string, object, object>)) {

                        return (T)(object)new Func<CallSite, string, object, object>(StringIndex);

                    }

                }

            }



            return base.BindDelegate<T>(site, args);

        }



        private object ListIndex(CallSite site, List target, object index) {

            if (target != null && index != null && index.GetType() == typeof(int)) {

                return target[(int)index];

            }



            return ((CallSite<Func<CallSite, List, object, object>>)site).Update(site, target, index);

        }



        private object ListIndex(CallSite site, object target, object index) {

            // using as is ok here because [] is virtual and will call the user method if

            // we have a user defined subclass of list.

            List lst = target as List;

            if (lst != null && index != null && index.GetType() == typeof(int)) {

                return lst[(int)index];

            }



            return ((CallSite<Func<CallSite, object, object, object>>)site).Update(site, target, index);

        }



        private object ListIndex(CallSite site, object target, int index) {

            List lst = target as List;

            if (lst != null) {

                return lst[index];

            }



            return ((CallSite<Func<CallSite, object, int, object>>)site).Update(site, target, index);

        }



        private object TupleIndex(CallSite site, PythonTuple target, object index) {

            if (target != null && index != null && index.GetType() == typeof(int)) {

                return target[(int)index];

            }



            return ((CallSite<Func<CallSite, PythonTuple, object, object>>)site).Update(site, target, index);

        }



        private object TupleIndex(CallSite site, object target, object index) {

            PythonTuple lst = target as PythonTuple;

            if (lst != null && index != null && index.GetType() == typeof(int)) {

                return lst[(int)index];

            }

            

            return ((CallSite<Func<CallSite, object, object, object>>)site).Update(site, target, index);

        }



        private object TupleIndex(CallSite site, object target, int index) {

            PythonTuple lst = target as PythonTuple;

            if (lst != null) {

                return lst[index];

            }



            return ((CallSite<Func<CallSite, object, int, object>>)site).Update(site, target, index);

        }



        private object StringIndex(CallSite site, string target, object index) {

            if (target != null && index != null && index.GetType() == typeof(int)) {

                return StringOps.GetItem(target, (int)index);

            }



            return ((CallSite<Func<CallSite, string, object, object>>)site).Update(site, target, index);

        }



        private object StringIndex(CallSite site, object target, object index) {

            string str = target as string;

            if (str != null && index != null && index.GetType() == typeof(int)) {

                return StringOps.GetItem(str, (int)index);

            }



            return ((CallSite<Func<CallSite, object, object, object>>)site).Update(site, target, index);

        }



        private object StringIndex(CallSite site, object target, int index) {

            string str = target as string;

            if (str != null) {

                return StringOps.GetItem(str, index);

            }



            return ((CallSite<Func<CallSite, object, int, object>>)site).Update(site, target, index);

        }



        public override int GetHashCode() {

            return base.GetHashCode() ^ _context.Binder.GetHashCode();

        }



        public override bool Equals(object obj) {

            PythonGetIndexBinder ob = obj as PythonGetIndexBinder;

            if (ob == null) {

                return false;

            }



            return ob._context.Binder == _context.Binder && base.Equals(obj);

        }



        #region IPythonSite Members



        public PythonContext/*!*/ Context {

            get { return _context; }

        }



        #endregion



        #region IExpressionSerializable Members



        public Expression/*!*/ CreateExpression() {

            return Ast.Call(

                typeof(PythonOps).GetMethod("MakeGetIndexAction"),

                BindingHelpers.CreateBinderStateExpression(),

                AstUtils.Constant(CallInfo.ArgumentCount)

            );

        }



        #endregion

    }

}