Re: \if, \elseif, \else, \endif (was Re: PSQL commands: \quit_if, \quit_unless)

On Sat, Feb 4, 2017 at 11:53 AM, Corey Huinker <corey(dot)huinker(at)gmail(dot)com>
wrote:

> The check I was suggesting on whether Ctrl+C has been pressed
>> on an empty line seems harder to implement, because get_interactive()
>> just calls readline() or fgets(), which block to return when a whole
>> line is ready. AFAICS psql can't know what was the edit-in-progress
>> when these functions are interrupted by a signal instead of
>> returning normally.
>> But I don't think this check is essential, it could be left to another
>> patch.
>>
>
> Glad I wasn't missing something obvious.
> I suppose we could base the behavior on whether there's at least one full
> line already buffered.
> However, I agree that it can be left to another patch.
>

v6 patch. highlights:
- error messages are now a bit more terse, following suggestions
- help text is more terse and Conditionals section was moved below Input
Output
- leverage IFSTATE_NONE a bit to fold some not-in-a-branch cases into
existing switch statements, giving flatter, slightly cleaner code and that
addresses expected cases before exceptional ones
- comments highlight which messages are printed in both interactive and
script mode.
- put Fabien's tap test in place verbatim
- No mention of Ctrl-C or PROMPT. Those can be addressed in separate
patches.

There's probably some more consensus building to do over the interactive
messages and comments, and if interactive-ish tests are possible with TAP,
we should add those too.