Re: writing new regexp functions

On Fri, 2 Feb 2007, Jeremy Drake wrote:

> I just coded up for this:
>
> CREATE FUNCTION regexp_matches(IN str text, IN pattern text) RETURNS
> text[]
> AS 'MODULE_PATHNAME', 'regexp_matches'
> LANGUAGE C IMMUTABLE STRICT;
>
> CREATE FUNCTION regexp_matches(
> IN str text, IN pattern text, IN return_pre_and_post bool,
> OUT prematch text, OUT fullmatch text, OUT matches text[], OUT
> postmatch text) RETURNS record
> AS 'MODULE_PATHNAME', 'regexp_matches'
> LANGUAGE C IMMUTABLE STRICT;
>

I wanted to put out there the question of what order the parameters to
these regex functions should go. ISTM most people expect them to go
(pattern, string), but I made these functions consistant with
substring(text,text) which takes (string, pattern). Now I have been
working on a regexp_split function, which takes (pattern, string), which
is what someone familiar with the function from perl would expect, but is
not consistant with substring or now with my regexp_matches function.

I want to ask, should I break with following substring's precedent, and
put the pattern first (as most people probably would expect), or should I
break with perl's precedent and put the pattern second (to behave like
substring)?

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