Re: bison c-parse.y:1115.19-20: $$ for the midrule at $4 of `structsp' has no declared type

Alessandro Basili <alessandro.basili@cern.ch> wrote:
(snip)
> That's another key point it worries me a lot. My goal is not to fix the
> compiler, but start using it to build my program for the aforementioned
> architecture. I would assume the shift/reduce conflicts is resulting
> from an incorrect description of the language, but if I can be able to
> understand what kind of construct of the language will trigger the
> conflict I can probably avoid to use it in my program.


Shift/reduce conflicts are not unusual, and not necessarily bad.


They often come from ambiguities in the language being parsed,
nested if-then-else being a favorite example. In many languages
with if-then-else, the else is defined to go with the nearest if,
but the syntax description doesn't know that. Specifying that
resolves the shift/reduce conflict.


Still, it might be worth trying to understand where the
conflicts come from to be sure that it is part of the
language definition.


As I understand it, though, reduce/reduce conflicts are not so
usual, and should be considered errors.


-- glen

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