// 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;
namespace Nova.CodeDOM
{
/// <summary>
/// Multiplies one <see cref="Expression"/> by another.
/// </summary>
public class Multiply : BinaryArithmeticOperator
{
#region /* CONSTANTS */
/// <summary>
/// The internal name of the operator.
/// </summary>
public const string InternalName = NamePrefix + "Multiply";
#endregion
#region /* CONSTRUCTORS */
/// <summary>
/// Create a <see cref="Multiply"/> operator.
/// </summary>
public Multiply(Expression left, Expression right)
: base(left, right)
{ }
#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="BinaryOperator"/>.
/// </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 = 300;
/// <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
Parser.AddOperatorParsePoint(ParseToken, 100, Precedence, LeftAssociative, false, Parse);
}
/// <summary>
/// Parse a <see cref="Multiply"/> operator.
/// </summary>
public static Multiply Parse(Parser parser, CodeObject parent, ParseFlags flags)
{
// Verify that we have a left expression before proceeding, otherwise abort
// (this is to give the PointerIndirection operator a chance at parsing it)
if (parser.HasUnusedExpression)
return new Multiply(parser, parent);
return null;
}
protected Multiply(Parser parser, CodeObject parent)
: base(parser, parent)
{ }
/// <summary>
/// Get the precedence of the operator.
/// </summary>
public override int GetPrecedence()
{
return Precedence;
}
#endregion
#region /* RESOLVING */
/// <summary>
/// Multiply two constant objects.
/// Supported types are: string, bool, enum, decimal, double, float, ulong, long, uint, int, ushort, short, char, byte, sbyte.
/// </summary>
/// <returns>
/// The product of the two constants, using the appropriate result type, including promoting smaller
/// types to int. Returns null if the operation is invalid.
/// </returns>
protected override object EvaluateConstants(object leftConstant, object rightConstant)
{
// Null, string, boolean, or enum operands aren't supported
if (leftConstant == null || rightConstant == null || leftConstant is string || rightConstant is string
|| leftConstant is bool || rightConstant is bool || leftConstant is EnumConstant || rightConstant is EnumConstant)
return null;
// Do binary numeric promotions
if (leftConstant is decimal)
{
if (!(rightConstant is float || rightConstant is double))
return (decimal)leftConstant * Convert.ToDecimal(rightConstant);
return null; // The operation is invalid
}
if (rightConstant is decimal)
{
if (!(leftConstant is float || leftConstant is double))
return Convert.ToDecimal(leftConstant) * (decimal)rightConstant;
return null; // The operation is invalid
}
if (leftConstant is double)
return (double)leftConstant * Convert.ToDouble(rightConstant);
if (rightConstant is double)
return Convert.ToDouble(leftConstant) * (double)rightConstant;
if (leftConstant is float)
return (float)leftConstant * Convert.ToSingle(rightConstant);
if (rightConstant is float)
return Convert.ToSingle(leftConstant) * (float)rightConstant;
if (leftConstant is ulong)
{
if ((rightConstant is sbyte && (sbyte)rightConstant < 0) || (rightConstant is short && (short)rightConstant < 0)
|| (rightConstant is int && (int)rightConstant < 0) || (rightConstant is long && (long)rightConstant < 0))
return null; // The operation is invalid
return (ulong)leftConstant * Convert.ToUInt64(rightConstant);
}
if (rightConstant is ulong)
{
if ((leftConstant is sbyte && (sbyte)leftConstant < 0) || (leftConstant is short && (short)leftConstant < 0)
|| (leftConstant is int && (int)leftConstant < 0) || (leftConstant is long && (long)leftConstant < 0))
return null; // The operation is invalid
return Convert.ToUInt64(leftConstant) * (ulong)rightConstant;
}
if (leftConstant is long)
return (long)leftConstant * Convert.ToInt64(rightConstant);
if (rightConstant is long)
return Convert.ToInt64(leftConstant) * (long)rightConstant;
if (leftConstant is uint)
{
if ((rightConstant is sbyte && (sbyte)rightConstant < 0) || (rightConstant is short && (short)rightConstant < 0)
|| (rightConstant is int && (int)rightConstant < 0))
return Convert.ToInt64(leftConstant) * Convert.ToInt64(rightConstant);
return (uint)leftConstant * Convert.ToUInt32(rightConstant);
}
if (rightConstant is uint)
{
if ((leftConstant is sbyte && (sbyte)leftConstant < 0) || (leftConstant is short && (short)leftConstant < 0)
|| (leftConstant is int && (int)leftConstant < 0))
return Convert.ToInt64(leftConstant) * Convert.ToInt64(rightConstant);
return Convert.ToUInt32(leftConstant) * (uint)rightConstant;
}
// All other cases (with smaller integral types) get promoted to ints
return Convert.ToInt32(leftConstant) * Convert.ToInt32(rightConstant);
}
#endregion
}
}