Dropping branches before using a transformer

[taylorh140]

So im trying to evaluate some c like synatax

I have cases like this:
(cast)(Value)
(cast)Value
(Value)
Value

since the cast and value are both c names they are ambiguous
I can separate them using something like:

exp: exp_cast | group | val
    exp_cast: group (group|val)
    group: "(" exp ")"
    val: G_INT|DECI|HEXI|var
   var: C_NAME

when I do this I would like to drop the first branch of any exp_cast before I use a transformer that way I don't try and look up the value of a type. But I'm not sure how to do that.

Or perhaps there is a better way?

[taylorh140]

I think to answer my own question the solution was not do drop a branch before using a transformer. but to use another transformer to drop the branch for me.

class DropCast(Transformer):
def exp_cast(self,args) return args[1] # keep the thing you want

This transformer can do the thing.