Re: shift/reduce conflict with unary

[Evan Lavelle]

Actually, it turns out that the conflict is pretty obvious even without 
the debug output. consider this input:

"5 6 +4"

How do you expect this to be scanned? Does it contain 3 
summation_expressions ("5", "6", "+4") or 2 ("5", "6+4")? There's an 
ambiguity - you haven't defined an expression list in an unambiguuous way.

this is a very common problem - how do you define a list of something 
complex? Can you define expression lists to require a separator? How about

"5, 6, +4"  -> 3 expressions
"5, 6 +4"   -> 2 expressions



> Is
> it okay if I disregard the conflict if the grammar works anyway?

I personally think that this is a mistake, but it is commonly done. The 
problems are that you may not understand why there is a conflict in the 
first place, and any subsequent maintainers certainly won't understand; 
I prefer to try to remove the conflict.

Evan