Re: makeAndExpr(), etc. confined to gram.y?

Amit Langote <amitlangote09(at)gmail(dot)com> writes:
> On Wed, Jun 25, 2014 at 1:27 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Amit Langote <amitlangote09(at)gmail(dot)com> writes:
>>> Is there a reason why they've been left out of
>>> makefuncs.h/makefuncs.c? Perhaps they are not supposed to be used
>>> outside gram.y at all? For example, previously a caller (potentially)
>>> outside parser could do a makeA_Expr(AEXPR_AND, ...). I guess this is
>>> no longer possible with AEXPR_AND gone?

>> What would be the purpose? There is noplace except gram.y that builds
>> raw parse trees.

> Yeah, that is true. Sorry, I am unaware as to how generic make*
> functions in gram.y are and how they differ from those in makefuncs.c.

> So, use of make* family of functions outside parser is their abuse in
> some way? Anything that needs to use these functions should somehow be
> accomplished in parser perhaps. For example, duplicate/redundant CHECK
> expressions elimination and such?

Well, the larger point here is that those functions are specific to
gram.y's problem of constructing multi-AND(OR) structures during a series
of binary production actions. I don't see that there's any use for them
elsewhere, and the way that they modify the input structures wouldn't
necessarily be safe anywhere else either.

regards, tom lane