private static Block ParseConcat(Block a, Block b, char type)
{
if (a == null)
{
return(SignBlock.Create(b, OperatorBlock.ToSignType(type)));
}
if (b == null)
{
throw new ArgumentNullException();
}
else
{
return(TwoOperatorBlock.Create(a, b, OperatorBlock.ToTwoOperatorType(type)));
}
}
public static Block Plus(this Block block)
{
return(SignBlock.Create(block, SignType.Plus));
}