On Tue, May 24, 2016 at 4:07 PM, David G. Johnston < david.g.johns...@gmail.com> wrote:
> On Tue, May 24, 2016 at 3:57 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > >> "David G. Johnston" <david.g.johns...@gmail.com> writes: >> > I just noticed this comment in scan.l: >> > /* >> > * GUC variables. This is a DIRECT violation of the warning given at >> the >> > * head of gram.y, ie flex/bison code must not depend on any GUC >> variables; >> > * as such, changing their values can induce very unintuitive behavior. >> > * But we shall have to live with it as a short-term thing until the >> switch >> > * to SQL-standard string syntax is complete. >> > */ >> > int backslash_quote = BACKSLASH_QUOTE_SAFE_ENCODING; >> > bool escape_string_warning = true; >> > bool standard_conforming_strings = true; >> >> > I'm not exactly sure what else needs to happen to remove these forbidden >> > GUCs and if we are not prepared to do this now when will we ever be... >> >> Dunno, are you prepared to bet that nobody is turning off >> standard_conforming_strings anymore? >> >> In any case, we keep adding new violations of this rule (cf >> operator_precedence_warning) so I have little hope that it will ever be >> completely clean. >> > > I tend to hold the same position. I'd probably update the last sentence > of the comment to reflect that reality. > > "We use them here due to the user-facing capability to change the parsing > rules of SQL-standard string literals." > > The switch is not likely to ever be "complete" and if so not likely in > whatever period the future reader might consider "short-term". > > FWIW I'm not intending to dig any deeper in this area of the codebase. I was actually trying to find "gram.y" via a GitHub search (OT - I'm finding that to be not the most usable tool...need to get better at git cli) and ended up seeing scan.l so I figured I'd read a few lines and got hit with that. I was trying to formulate an opinion of the "USING opclass" thread...decided that I'd take a pass on that at this time. David J.
