[postgis-devel] Function Removal

[Bruce Rindahl]

Right now Select ST_AsText(ST_MakePoint(1,2,4326)) returns POINT Z (1 2
4326)
Are we going to have to cast the input every time to make sure it's a
SRID?  That might be more confusing than ST_SetSRID(ST_MakePoint())

On Wed, Dec 16, 2020 at 11:41 AM Paul Ramsey <pramsey at cleverelephant.ca>
wrote:

> I feel like we've been over this before, but I ran into it again and I'm
> wondering what we think our best practice should be.
>
> The issue is the removal of stacked multi-parameter functions. We have:
>
>   CREATE FUNCTION ST_MakePoint(float8, float8)
>   CREATE FUNCTION ST_MakePoint(float8, float8, float8)
>   CREATE FUNCTION ST_MakePoint(float8, float8, float8, float8)
>
> What's missing here? A place to set the SRID! So we constantly have this
> formation:
>
>   ST_SetSRID(ST_MakePoint(...), ...)
>
> Which is, let's face it, ugly. So being a smart boy I thought:
>
>   CREATE FUNCTION ST_MakePoint(x float8, y float8, z float8 default null,
> m float8 default null, srid integer default null)
>
> And then I updated the underlying C function to handle the nulls, and it
> works wonderfully:
>
>   postgis=# select st_asewkt(ST_MakePoint(1, 2, srid => 123));
>   SRID=123;POINT(1 2)
>
> Except, unfortunately now the old form is broken.
>
>   postgis=# select st_asewkt(ST_MakePoint(1.2, 2.33));
>   ERROR:  function st_makepoint(double precision, double precision) is not
> unique
>   HINT:  Could not choose a best candidate function. You might need to add
> explicit type casts.
>
> Yeah, it could be either my new one or the two-parameter form of the old
> one.
>
> The obvious fix would be to remove the old signatures at the same time as
> adding the new one, but as I recall this leads to upgrade issues? This is
> where my memory is failing. I know (a) a single signature with defaults and
> argument names is nicer and cleaner and also (b) every time I've done it
> there's been some kind of an outcry / mess.
>
> Any help, thoughts?
>
> P
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