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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.
*
* You must not remove this notice, or any other, from this software.
*
*
* ***************************************************************************/
#if CLR2
using Microsoft.Scripting.Ast;
#else
using System.Linq.Expressions;
#endif
using System.Dynamic.Utils;
namespace System.Dynamic {
/// <summary>
/// Represents the unary dynamic operation at the call site, providing the binding semantic and the details about the operation.
/// </summary>
public abstract class UnaryOperationBinder : DynamicMetaObjectBinder {
private ExpressionType _operation;
/// <summary>
/// Initializes a new instance of the <see cref="BinaryOperationBinder"/> class.
/// </summary>
/// <param name="operation">The unary operation kind.</param>
protected UnaryOperationBinder(ExpressionType operation) {
ContractUtils.Requires(OperationIsValid(operation), "operation");
_operation = operation;
}
/// <summary>
/// The result type of the operation.
/// </summary>
public override sealed Type ReturnType {
get {
switch(_operation) {
case ExpressionType.IsFalse:
case ExpressionType.IsTrue:
return typeof(bool);
default:
return typeof(object);
}
}
}
/// <summary>
/// The unary operation kind.
/// </summary>
public ExpressionType Operation {
get {
return _operation;
}
}
/// <summary>
/// Performs the binding of the unary dynamic operation if the target dynamic object cannot bind.
/// </summary>
/// <param name="target">The target of the dynamic unary operation.</param>
/// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns>
public DynamicMetaObject FallbackUnaryOperation(DynamicMetaObject target) {
return FallbackUnaryOperation(target, null);
}
/// <summary>
/// Performs the binding of the unary dynamic operation if the target dynamic object cannot bind.
/// </summary>
/// <param name="target">The target of the dynamic unary operation.</param>
/// <param name="errorSuggestion">The binding result in case the binding fails, or null.</param>
/// <returns>The <see cref="DynamicMetaObject"/> representing the result of the binding.</returns>
public abstract DynamicMetaObject FallbackUnaryOperation(DynamicMetaObject target, DynamicMetaObject errorSuggestion);
/// <summary>
/// Performs the binding of the dynamic unary operation.
/// </summary>
/// <param name="target">The target of the dynamic operation.</param>
/// <param name="args">An array of arguments of the dynamic 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.Requires(args == null || args.Length == 0, "args");
return target.BindUnaryOperation(this);
}
// this is a standard DynamicMetaObjectBinder
internal override sealed bool IsStandardBinder {
get {
return true;
}
}
internal static bool OperationIsValid(ExpressionType operation) {
switch (operation) {
#region Generated Unary Operation Binder Validator
// *** BEGIN GENERATED CODE ***
// generated by function: gen_unop_validator from: generate_tree.py
case ExpressionType.Negate:
case ExpressionType.UnaryPlus:
case ExpressionType.Not:
case ExpressionType.Decrement:
case ExpressionType.Increment:
case ExpressionType.OnesComplement:
case ExpressionType.IsTrue:
case ExpressionType.IsFalse:
// *** END GENERATED CODE ***
#endregion
case ExpressionType.Extension:
return true;
default:
return false;
}
}
}
}
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