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

>
>
> All,
> As it is, I've added interactive mode psql_error notifications about the
> resulting branching state of any branching commands, and any attempt to
> send non-branching commands or queries while in an inactive branch will
> generate a psql_error saying that the command was ignored. Waiting til I
> get what should or shouldn't be done about prompts before issuing the next
> patch revision.
>

So far, interactive branching information will look like this (it prints on
every branching command and on every ignored command):

# \if true
active \if, executing commands
# select 1;
?column?
----------
1
(1 row)

Time: 0.282 ms
# \else
inactive \else, ignoring commands
# select 1;
inside inactive branch, query ignored.
# select
... # 1;
inside inactive branch, query ignored.
# \endif
active \endif, executing commands
# \if false
inactive \if, ignoring commands
# \i file_name
inside inactive branch, command ignored.
# \elif false
inactive \elif, ignoring commands
# \else
active \else, executing commands
# \endif
active \endif, executing commands

Comments welcome.