Re: Refactor construct_array() and deconstruct_array() for built-in types - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Refactor construct_array() and deconstruct_array() for built-in types
Date
Msg-id 1844517.1651502932@sss.pgh.pa.us
Whole thread Raw
In response to Refactor construct_array() and deconstruct_array() for built-in types  (Peter Eisentraut <peter.eisentraut@enterprisedb.com>)
Responses Re: Refactor construct_array() and deconstruct_array() for built-in types  (Peter Eisentraut <peter.eisentraut@enterprisedb.com>)
List pgsql-hackers
Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
> There are many calls to construct_array() and deconstruct_array() for 
> built-in types, for example, when dealing with system catalog columns. 
> These all hardcode the type attributes necessary to pass to these functions.

> To simplify this a bit, add construct_array_builtin(), 
> deconstruct_array_builtin() as wrappers that centralize this hardcoded 
> knowledge.  This simplifies many call sites and reduces the amount of 
> hardcoded stuff that is spread around.

> I also considered having genbki.pl generate lookup tables for these 
> hardcoded values, similar to schemapg.h, but that ultimately seemed 
> excessive.

+1 --- the added overhead of the switch statements is probably a
reasonable price to pay for the notational simplification and
bug-proofing.

One minor coding gripe is that compilers that don't know that elog(ERROR)
doesn't return will certainly generate "use of possibly-uninitialized
variable" complaints.  Suggest inserting "return NULL;" or similar into
the default: cases.  I'd also use more specific error wording to help
people find where they need to add code when they make use of a new type;
maybe like "type %u not supported by construct_array_builtin".

            regards, tom lane



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