// The Nova Project by Ken Beckett.
// Copyright (C) 2007-2012 Inevitable Software, all rights reserved.
// Released under the Common Development and Distribution License, CDDL-1.0: http://opensource.org/licenses/cddl1.php
using System;
using Nova.Parsing;
using Nova.Utilities;
namespace Nova.CodeDOM
{
/// <summary>
/// Performs a one's complement (toggles all bits) on an <see cref="Expression"/>.
/// </summary>
public class Complement : PreUnaryOperator
{
#region /* CONSTANTS */
/// <summary>
/// The internal name of the operator.
/// </summary>
public const string InternalName = NamePrefix + "OnesComplement";
#endregion
#region /* CONSTRUCTORS */
/// <summary>
/// Create a <see cref="Complement"/> operator.
/// </summary>
public Complement(Expression expression)
: base(expression)
{ }
#endregion
#region /* PROPERTIES */
/// <summary>
/// The symbol associated with the operator.
/// </summary>
public override string Symbol
{
get { return ParseToken; }
}
#endregion
#region /* METHODS */
/// <summary>
/// The internal name of the <see cref="UnaryOperator"/>.
/// </summary>
public override string GetInternalName()
{
return InternalName;
}
#endregion
#region /* PARSING */
/// <summary>
/// The token used to parse the code object.
/// </summary>
public const string ParseToken = "~";
/// <summary>
/// The precedence of the operator.
/// </summary>
public const int Precedence = 200;
/// <summary>
/// True if the operator is left-associative, or false if it's right-associative.
/// </summary>
public const bool LeftAssociative = true;
internal static new void AddParsePoints()
{
// Use a parse-priority of 100 (DestructorDecl uses 0)
Parser.AddOperatorParsePoint(ParseToken, 100, Precedence, LeftAssociative, true, Parse);
}
/// <summary>
/// Parse a <see cref="Complement"/>.
/// </summary>
public static Complement Parse(Parser parser, CodeObject parent, ParseFlags flags)
{
return new Complement(parser, parent);
}
protected Complement(Parser parser, CodeObject parent)
: base(parser, parent, false)
{ }
/// <summary>
/// Get the precedence of the operator.
/// </summary>
public override int GetPrecedence()
{
return Precedence;
}
#endregion
#region /* RESOLVING */
/// <summary>
/// Evaluate the type of the <see cref="Expression"/>.
/// </summary>
/// <returns>The resulting <see cref="TypeRef"/> or <see cref="UnresolvedRef"/>.</returns>
public override TypeRefBase EvaluateType(bool withoutConstants)
{
// If we have a reference to an overloaded operator declaration, use its return type
if (_operatorRef is OperatorRef)
return ((OperatorRef)_operatorRef).GetReturnType();
// Determine the type of the expression
TypeRefBase typeRefBase = _expression.EvaluateType(withoutConstants);
if (typeRefBase is TypeRef)
{
// Handle a constant
if (typeRefBase.IsConst)
{
object result = EvaluateConstant(typeRefBase.GetConstantValue());
return (result != null ? new TypeRef(result) : typeRefBase);
}
// String, boolean, or enum operands aren't supported by default, but we'll just return the
// unchanged type instead of 'object'.
// Do unary numeric promotions
if (typeRefBase.IsSameRef(TypeRef.ShortRef) || typeRefBase.IsSameRef(TypeRef.UShortRef)
|| typeRefBase.IsSameRef(TypeRef.SByteRef) || typeRefBase.IsSameRef(TypeRef.ByteRef) || typeRefBase.IsSameRef(TypeRef.CharRef))
return TypeRef.IntRef;
}
// By default, the type is unchanged
return typeRefBase;
}
/// <summary>
/// Perform a bit-wise complement of a constant object.
/// Supported types are: string, bool, enum, decimal, double, float, ulong, long, uint, int, ushort, short, char, byte, sbyte.
/// </summary>
/// <returns>
/// The result, using the appropriate result type, including promoting smaller types to int. Returns null if the operation is invalid.
/// </returns>
protected override object EvaluateConstant(object constant)
{
// Null, string, or boolean operands aren't supported
if (constant == null || constant is string || constant is bool)
return null; // The operation is invalid
// Handle enum constant
if (constant is EnumConstant)
{
EnumConstant enumConstant = (EnumConstant)constant;
object constantValue = enumConstant.ConstantValue;
object enumValue = EvaluateConstant(constantValue);
// If the calculated value was promoted to an int, convert it back to the original type
if (enumValue is int && !(constantValue is int))
enumValue = TypeUtil.ChangeType(enumValue, constantValue.GetType());
return new EnumConstant(enumConstant.EnumTypeRef, enumValue);
}
// Do unary numeric promotions
if (constant is decimal || constant is double || constant is float)
return null; // The operation is invalid
if (constant is ulong)
return ~(ulong)constant;
if (constant is long)
return ~(long)constant;
if (constant is uint)
return ~(uint)constant;
if (constant is int)
return ~(int)constant;
// All other cases (with smaller integral types) get promoted to ints
return ~Convert.ToInt32(constant);
}
#endregion
}
}