Re: newbie question on Bison/Yacc

golova@my-deja.com writes:


> I am totally new to yacc/bison and wondering if you could help me with
> the following question: I need to parse an algebraic expression and
> calculate its value at a bunch of different points; what are the ways
> (the fastest way?) to reset the "independent vars" and recalculate the
> expression again?


I recommend to build a "symbol table", which maps variable names to
their assigned values. How efficient that is is not really a matter of
bison; you need a fast way to find an identifier in the symbol table
(e.g. by hashing), and you probably need a fast way to clear part of
the variable names when there scope is left (e.g. by chaining multiple
symbol tables, and then discarding the innermost one).


Regards,
Martin

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