"Jess Gabriel y Galn" <jgabrielygalan / gmail.com> wrote in post #969520:
> you can do that easily with method_missing

Thanks. it looks like a promising solution. but I have two more requirements:

1. what if the event name includes a dot '.'?
2. I also want the left value of the equation (metric_A in the example) to be added into the Hash, because it is possible that a new metric needs to be calculated based on the existing metric.