protected override ScriptVariable CalculateInternal(ScriptExecutionEnvironment env)
{
ScriptVariable left = this.Left.Calculate(env);
// ショートサーキット演算子
switch (this.Operator)
{
case OperatorType.And:
if (left == null)
{
return(null);
}
if (!left.ToBoolean())
{
return(new BooleanVariable(false));
}
return(this.Right.Calculate(env));
case OperatorType.Or:
if (left == null)
{
return(null);
}
if (left.ToBoolean())
{
return(new BooleanVariable(true));
}
return(this.Right.Calculate(env));
}
// 右辺
ScriptVariable right = this.Right.Calculate(env);
if (left == null || right == null)
{
// 片方nullの場合は等価比較演算以外はnull
switch (this.Operator)
{
case OperatorType.Eq:
return(new BooleanVariable(left == right));
case OperatorType.Ne:
return(new BooleanVariable(left != right));
default:
return(null);
}
}
// 普通の二項演算
switch (this.Operator)
{
case OperatorType.Cross:
return(left.Multiply(right));
case OperatorType.Plus:
return(left.Add(right));
case OperatorType.Minus:
return(left.Subtract(right));
case OperatorType.Slash:
return(left.Divide(right));
case OperatorType.Percent:
return(left.Remainder(right));
}
// 比較演算子
int?tmp = left.CompareTo(right);
if (tmp.HasValue)
{
int value = tmp.Value;
switch (this.Operator)
{
case OperatorType.Eq:
return(new BooleanVariable(value == 0));
case OperatorType.Ne:
return(new BooleanVariable(value != 0));
case OperatorType.Gt:
return(new BooleanVariable(value > 0));
case OperatorType.Ge:
return(new BooleanVariable(value >= 0));
case OperatorType.Lt:
return(new BooleanVariable(value < 0));
case OperatorType.Le:
return(new BooleanVariable(value <= 0));
}
}
return(null);
}