/Microsoft.Scripting.Core/Ast/ElementInit.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 CODEPLEX_40

using System;

#else

using System; using Microsoft;

#endif

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Reflection;

using System.Text;

#if CODEPLEX_40

using System.Dynamic.Utils;

#else

using Microsoft.Scripting.Utils;

#endif



#if CODEPLEX_40

namespace System.Linq.Expressions {

#else

namespace Microsoft.Linq.Expressions {

#endif

    /// <summary>

    /// Represents the initialization of a list.

    /// </summary>

    public sealed class ElementInit : IArgumentProvider {

        private MethodInfo _addMethod;

        private ReadOnlyCollection<Expression> _arguments;



        internal ElementInit(MethodInfo addMethod, ReadOnlyCollection<Expression> arguments) {

            _addMethod = addMethod;

            _arguments = arguments;

        }

        /// <summary>

        /// Gets the <see cref="MethodInfo"/> used to add elements to the object.

        /// </summary>

        public MethodInfo AddMethod {

            get { return _addMethod; }

        }



        /// <summary>

        /// Gets the list of elements to be added to the object.

        /// </summary>

        public ReadOnlyCollection<Expression> Arguments {

            get { return _arguments; }

        }



        Expression IArgumentProvider.GetArgument(int index) {

            return _arguments[index];

        }



        int IArgumentProvider.ArgumentCount {

            get {

                return _arguments.Count;

            }

        }



        /// <summary>

        /// Creates a <see cref="String"/> representation of the node.

        /// </summary>

        /// <returns>A <see cref="String"/> representation of the node.</returns>

        public override string ToString() {

            return ExpressionStringBuilder.ElementInitBindingToString(this);

        }

    }





    public partial class Expression {

        /// <summary>

        /// Creates an <see cref="Microsoft.Linq.Expressions.ElementInit">ElementInit</see> expression that represents the initialization of a list.

        /// </summary>

        /// <param name="addMethod">The <see cref="MethodInfo"/> for the list's Add method.</param>

        /// <param name="arguments">An array containing the Expressions to be used to initialize the list.</param>

        /// <returns>The created <see cref="Microsoft.Linq.Expressions.ElementInit">ElementInit</see> expression.</returns>

        public static ElementInit ElementInit(MethodInfo addMethod, params Expression[] arguments) {

            return ElementInit(addMethod, arguments as IEnumerable<Expression>);

        }



        /// <summary>

        /// Creates an <see cref="Microsoft.Linq.Expressions.ElementInit">ElementInit</see> expression that represents the initialization of a list.

        /// </summary>

        /// <param name="addMethod">The <see cref="MethodInfo"/> for the list's Add method.</param>

        /// <param name="arguments">An <see cref="IEnumerable{T}"/> containing <see cref="Expression"/> elements to initialize the list.</param>

        /// <returns>The created <see cref="Microsoft.Linq.Expressions.ElementInit">ElementInit</see> expression.</returns>

        public static ElementInit ElementInit(MethodInfo addMethod, IEnumerable<Expression> arguments) {

            ContractUtils.RequiresNotNull(addMethod, "addMethod");

            ContractUtils.RequiresNotNull(arguments, "arguments");



            var argumentsRO = arguments.ToReadOnly();



            RequiresCanRead(argumentsRO, "arguments");

            ValidateElementInitAddMethodInfo(addMethod);

            ValidateArgumentTypes(addMethod, ExpressionType.Call, ref argumentsRO);

            return new ElementInit(addMethod, argumentsRO);

        }



        private static void ValidateElementInitAddMethodInfo(MethodInfo addMethod) {

            ValidateMethodInfo(addMethod);

            ParameterInfo[] pis = addMethod.GetParametersCached();

            if (pis.Length == 0) {

                throw Error.ElementInitializerMethodWithZeroArgs();

            }

            if (!addMethod.Name.Equals("Add", StringComparison.OrdinalIgnoreCase)) {

                throw Error.ElementInitializerMethodNotAdd();

            }

            if (addMethod.IsStatic) {

                throw Error.ElementInitializerMethodStatic();

            }

            foreach (ParameterInfo pi in pis) {

                if (pi.ParameterType.IsByRef) {

                    throw Error.ElementInitializerMethodNoRefOutParam(pi.Name, addMethod.Name);

                }

            }

        }

    }

}