Re: FYI: fix %start after first rule

[Akim Demaille]

>>> "Joel" == Joel E Denny <address@hidden> writes:

 > 3. In general I think it's easier to evolve Bison when the syntax
 > analysis of the user grammar file is a separate phase from the
 > semantic analysis as much as possible.  That is, Bison shouldn't
 > try to understand user declarations until it has read them all.

I totally subscribe to this view from the implementation point of
view.  Still, I am in favor of having a semantic pass doing a regular
left to right analysis, where entities are expected to be defined (or
declared) before being used.

 > In many cases, I agree that we should encourage a specific coding
 > style.  Requiring %start to be in the definitions section maybe
 > always makes sense.  I won't argue if we change parse-gram.y
 > accordingly (but I hope we won't revert the changes I made).  We
 > can always change it back later if we discover a need.

I'm in between: I don't see why this should be only in the prologue,
but it should not be after what it refers to.

 > In other cases, I think we should trust the user to figure out what is the 
 > right style for his grammar.  For example, I *sometimes* like to be able 
 > to declare `%type <my_field> my_nt' next to the one set of rules for which 
 > my_nt is the LHS.

That's the reason why I relaxed the constraint on the prologue
directives :)  But that's different, it is a matter of *modularity*,
not of commutativity.