/IronPython_Main/Runtime/Microsoft.Scripting.Core/Actions/SetIndexBinder.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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using System.Dynamic.Utils;



namespace System.Dynamic {



    /// <summary>

    /// Represents the dynamic set index operation at the call site, providing the binding semantic and the details about the operation.

    /// </summary>

    public abstract class SetIndexBinder : DynamicMetaObjectBinder {

        private readonly CallInfo _callInfo;



        /// <summary>

        /// Initializes a new instance of the <see cref="SetIndexBinder" />.

        /// </summary>

        /// <param name="callInfo">The signature of the arguments at the call site.</param>

        protected SetIndexBinder(CallInfo callInfo) {

            ContractUtils.RequiresNotNull(callInfo, "callInfo");

            _callInfo = callInfo;

        }



        /// <summary>

        /// The result type of the operation.

        /// </summary>

        public override sealed Type ReturnType {

            get { return typeof(object); }

        }



        /// <summary>

        /// Gets the signature of the arguments at the call site.

        /// </summary>

        public CallInfo CallInfo {

            get { return _callInfo; }

        }



        /// <summary>

        /// Performs the binding of the dynamic set index operation.

        /// </summary>

        /// <param name="target">The target of the dynamic set index operation.</param>

        /// <param name="args">An array of arguments of the dynamic set index operation.</param>

        /// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns>

        public sealed override DynamicMetaObject Bind(DynamicMetaObject target, DynamicMetaObject[] args) {

            ContractUtils.RequiresNotNull(target, "target");

            ContractUtils.RequiresNotNull(args, "args");

            ContractUtils.Requires(args.Length >= 2, "args");



            DynamicMetaObject value = args[args.Length - 1];

            DynamicMetaObject[] indexes = args.RemoveLast();



            ContractUtils.RequiresNotNull(value, "args");

            ContractUtils.RequiresNotNullItems(indexes, "args");



            return target.BindSetIndex(this, indexes, value);

        }



        // this is a standard DynamicMetaObjectBinder

        internal override sealed bool IsStandardBinder {

            get {

                return true;

            }

        }



        /// <summary>

        /// Performs the binding of the dynamic set index operation if the target dynamic object cannot bind.

        /// </summary>

        /// <param name="target">The target of the dynamic set index operation.</param>

        /// <param name="indexes">The arguments of the dynamic set index operation.</param>

        /// <param name="value">The value to set to the collection.</param>

        /// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns>

        public DynamicMetaObject FallbackSetIndex(DynamicMetaObject target, DynamicMetaObject[] indexes, DynamicMetaObject value) {

            return FallbackSetIndex(target, indexes, value, null);

        }



        /// <summary>

        /// When overridden in the derived class, performs the binding of the dynamic set index operation if the target dynamic object cannot bind.

        /// </summary>

        /// <param name="target">The target of the dynamic set index operation.</param>

        /// <param name="indexes">The arguments of the dynamic set index operation.</param>

        /// <param name="value">The value to set to the collection.</param>

        /// <param name="errorSuggestion">The binding result to use if binding fails, or null.</param>

        /// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns>

        public abstract DynamicMetaObject FallbackSetIndex(DynamicMetaObject target, DynamicMetaObject[] indexes, DynamicMetaObject value, DynamicMetaObject errorSuggestion);

    }

}