CREATE TYPE c AS (r float, i float); CREATE FUNCTION mag(c c) RETURNS float LANGUAGE sql AS $$ SELECT sqrt(c.r^2 + c.i^2) $$; SELECT mag( (2.2, 2.2) ); mag ------------------ 3.11126983722081
But this doesn't: CREATE FUNCTION magsum( c c[] ) RETURNS float LANGUAGE sql AS $$ SELECT sum(sqrt(c.r^2 + c.i^2)) FROM unnest(c) c $$; SELECT magsum( array[row(2.1, 2.1), row(2.2,2.2)] ); ERROR: function magsum(record[]) does not exist at character 8
Presumably we're playing some games with resolving (...) into a complex type instead of a raw record; what would be involved with making that work for an array of a complex type? I don't see anything array-specific in parse_func.c, so I'm not sure what the path for this is...
magsum( c c[] ) never gets a chance to coerce its argument because array[row(...), row(...)]
beats it to the punch. SELECT mag( row(...) ) does see the untyped row and seeing only a single function with parameter "c" coerces it to match. I'm not sure what can be done besides adding the cast to either the array[]::c[] or to the individual items array[ row(...)::c ].
Hopefully the thought helps because I'm useless when it comes to the actual code.
This does seem similar to how non-array literals are treated; though I'm not sure if there are inferences (or node look-through) occurring in literals that make some cases like this work while the corresponding "unknown record" gets set in stone differently.
