Performance impact of "redundant" rules

[Frans Englich]

Hi everyone,

Sometimes I write grammar constructs like this:

StringLiteral: STRING_LITERAL

and use StringLiteral in subsequent rules, instead of STRING_LITERAL directly. 
The reason is readability, and to stay consistent with an EBNF specification.

I wonder, does this cause a negative performance impact? When I compile the 
parser with extra debug output I see that it actually performs a 
STRING_LITERAL --> StringLiteral reduction.


Thanks in advance,

                Frans