#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#endregion
using System;
using System.Collections;
using System.Runtime.Serialization;
using Spring.Collections;
using Spring.Util;
namespace Spring.Expressions{
/// <summary>
/// Represents arithmetic subtraction operator.
/// </summary>
/// <author>Aleksandar Seovic</author>
[Serializable]
public class OpSUBTRACT : BinaryOperator
{
/// <summary>
/// Create a new instance
/// </summary>
public OpSUBTRACT():base()
{
}
/// <summary>
/// Create a new instance from SerializationInfo
/// </summary>
protected OpSUBTRACT(SerializationInfo info, StreamingContext context)
: base(info, context)
{
}
/// <summary>
/// Returns a value for the arithmetic subtraction operator node.
/// </summary>
/// <param name="context">Context to evaluate expressions against.</param>
/// <param name="evalContext">Current expression evaluation context.</param>
/// <returns>Node's value.</returns>
protected override object Get(object context, EvaluationContext evalContext)
{
object left = GetLeftValue( context, evalContext );
object right = GetRightValue( context, evalContext );
if (NumberUtils.IsNumber(left) && NumberUtils.IsNumber(right))
{
return NumberUtils.Subtract(left, right);
}
else if (left is DateTime && (right is TimeSpan || right is string || NumberUtils.IsNumber(right)))
{
if (NumberUtils.IsNumber(right))
{
right = TimeSpan.FromDays(Convert.ToDouble(right));
}
else if (right is string)
{
right = TimeSpan.Parse((string) right);
}
return (DateTime) left - (TimeSpan) right;
}
else if (left is DateTime && right is DateTime)
{
return (DateTime) left - (DateTime) right;
}
else if (left is IList || left is ISet)
{
ISet leftset = new HybridSet(left as ICollection);
ISet rightset;
if(right is IList || right is ISet)
{
rightset = new HybridSet(right as ICollection);
}
else if (right is IDictionary)
{
rightset = new HybridSet(((IDictionary) right).Keys);
}
else
{
throw new ArgumentException("Cannot subtract instances of '"
+ left.GetType().FullName
+ "' and '"
+ right.GetType().FullName
+ "'.");
}
return leftset.Minus(rightset);
}
else if (left is IDictionary)
{
ISet leftset = new HybridSet(((IDictionary) left).Keys);
ISet rightset;
if (right is IList || right is ISet)
{
rightset = new HybridSet(right as ICollection);
}
else if (right is IDictionary)
{
rightset = new HybridSet(((IDictionary) right).Keys);
}
else
{
throw new ArgumentException("Cannot subtract instances of '"
+ left.GetType().FullName
+ "' and '"
+ right.GetType().FullName
+ "'.");
}
IDictionary result = new Hashtable(rightset.Count);
foreach(object key in leftset.Minus(rightset))
{
result.Add(key, ((IDictionary)left)[key]);
}
return result;
}
else
{
throw new ArgumentException("Cannot subtract instances of '"
+ left.GetType().FullName
+ "' and '"
+ right.GetType().FullName
+ "'.");
}
}
}
}
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