Pavel Stehule <pavel.stehule@gmail.com> writes:
> I looked on some constructs that helps with iteration over array in
> plpgsql. I propose a following syntax:
> FOR var IN [array variable | array expression]
> LOOP
I don't have any opinion about whether the functionality proposed here
is worth the trouble, but I do have an opinion about that syntax: it's
an awful choice. plpgsql has enough trouble already distinguishing
between integer for-loops and query for-loops, not to mention trouble
in producing a helpful error message when somebody gets either of those
constructs slightly wrong. Providing a variant where a single
expression can follow IN will make both of those problems an order of
magnitude worse. As an example, is this a for-in-query or a
for-in-array?
FOR v IN (SELECT arraycol FROM tab) LOOP ...
Either answer is plausible depending on whether you assume the
parentheses make it a subquery.
Pick something less easily confusable with the existing constructs.
regards, tom lane