YAMP.RangeOperator.Perform C# (CSharp) Method

        public override Value Perform(Value left, Value right)
        {
            var step = 1.0;
            var explicitStep = false;
            var start = 0.0;
            var end = 0.0;
            var all = false;

            if (left is ScalarValue)
            {
                start = (left as ScalarValue).Re;
            }
            else if (left is RangeValue)
            {
                var m = left as RangeValue;
                start = m.Start;
                step = m.End;
                explicitStep = true;
            }
            else
            {
                throw new YAMPOperationInvalidException(":", left);
            }

            if (right is ScalarValue)
            {
                end = (right as ScalarValue).Re;
            }
            else if (right is RangeValue)
            {
                var m = right as RangeValue;
                step = m.Start;
                end = m.End;
                all = m.All;
                explicitStep = true;
            }
            else if (right is StringValue)
            {
                all = (right as StringValue).Value.Equals(End);
            }
            else
            {
                throw new YAMPOperationInvalidException(":", left);
            }

            if (!all && !explicitStep && end < start)
            {
                step = -1.0;
            }

            if (all)
            {
                return new RangeValue(start, step);
            }

            return new RangeValue(start, end, step);
        }