Associative array "pop" ?

Associative array "pop" ?

[Craig Ringer]

Hi all

I find myself using the patterns

x_foo = foo[x]
if (x_foo != 0)
    delete foo[x]
    # do something with x_foo
}

and

if ([x] in foo) {
    x_foo = foo[x]
    delete foo[x]
    # do something with x_foo
}

frequently.

I wonder if it's feasible to have a "pop" that combines these to eliminate
repeated searches of the array. Assuming that those aren't already
optimised away - I didn't see any indication they are, but don't know the
underlying code well enough.

Something like

    if (pop(foo_x, foo[x])) {
    }

where "pop" returns 1 if the element was present, 0 if it was not present,
and deletes it if it was present.

If you think it's a good idea I'll pop this on my TODO for pending
enhancements for me to try to hack up.

-- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 2ndQuadrant - PostgreSQL Solutions for the Enterprise

Re: Associative array "pop" ?

[Frank Ch. Eigler]

Craig Ringer <craig@2ndquadrant.com> writes:

> x_foo = foo[x]
> if (x_foo != 0)
>     delete foo[x]
>     # do something with x_foo
> }

This is probably:

https://sourceware.org/bugzilla/show_bug.cgi?id=10837

... except the "value = delete foo[i]" syntax is kind of meh, and
doesn't work with slice ops like "delete foo[*]".  A functional syntax
like @pop() would look okay.  We try to not introduce new keywords,
except in the @-space, and even there only with version-conditional
parsing.

- FChE