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

On Fri, Mar 17, 2017 at 2:18 PM, Corey Huinker <corey(dot)huinker(at)gmail(dot)com>
wrote:

>
>> > \set x 'arg1 arg2'
>>
>> > \if false
>> > \cmd_that_takes_exactly_two_args :x
>> > \endif
>>
>> Yeah, throwing errors for bad arguments would also need to be suppressed.
>>
>> regards, tom lane
>>
>
> Ok, barring other feedback, I'm going to take my marching orders as "make
> each slash command active-aware". To keep that sane, I'm probably going to
> break out each slash command family into it's own static function.
>

...and here it is.

v24 highlights:

- finally using git format-patch
- all conditional slash commands broken out into their own functions
(exec_command_$NAME) , each one tests if it's in an active branch, and if
it's not it consumes the same number of parameters, but discards them.
comments for each slash-command family were left as-is, may need to be
bulked up.
- TAP tests discarded in favor of one ON_EROR_STOP test for invalid \elif
placement
- documentation recommending ON_ERROR_STOP removed, because invalid
expressions no longer throw off if-endif balance
- documentation updated to reflex that contextually-correct-but-invalid
boolean expressions are treated as false
- psql_get_variable has a passthrough void pointer now, but I ended up not
needing it. Instead, all slash commands in false blocks either fetch
OT_NO_EVAL or OT_WHOLE_LINE options. If I'm missing something, let me know.