44 lines
1.6 KiB
C#
44 lines
1.6 KiB
C#
using System;
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namespace VAR.ExpressionEvaluator
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{
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public class ExpressionMinusNode : ExpressionBinaryNode
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{
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public ExpressionMinusNode(IExpressionNode leftNode, IExpressionNode rightNode) :
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base(leftNode, rightNode, MinusOp)
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{
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}
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private static object MinusOp(object leftValue, object rightValue)
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{
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if (leftValue == null || rightValue == null)
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{
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return null;
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}
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if (leftValue is string)
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{
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if (decimal.TryParse((string)leftValue, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out decimal dec) == false)
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{
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throw new Exception(string.Format("Can't convert to decimal string value \"{0}\"", (string)leftValue));
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}
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leftValue = dec;
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}
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if (rightValue is string)
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{
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if (decimal.TryParse((string)rightValue, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out decimal dec) == false)
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{
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throw new Exception(string.Format("Can't convert to decimal string value \"{0}\"", (string)rightValue));
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}
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rightValue = dec;
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}
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if ((leftValue is decimal) == false || (rightValue is decimal) == false)
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{
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throw new Exception("Can't substract non decimal values");
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}
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return (decimal)leftValue - (decimal)rightValue;
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}
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}
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}
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