diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2020-03-13 12:49:10 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2020-03-13 12:49:10 -0400 |
| commit | 00f38866f7e966ac4c48c6b027e2666c3ab29398 (patch) | |
| tree | e1c1054f6906844322fb8de109ae54b66fb015d6 /doc/src | |
| parent | 02530da73f0438f7c2073267de6fe2be84f592d7 (diff) | |
Doc: fix mistaken reference to "PG_ARGNULL_xxx()" macro.
This should of course be just "PG_ARGISNULL()".
Also reorder a couple of paras to make the discussion of PG_ARGISNULL
less disjointed.
Back-patch to v10 where the error was introduced.
Laurenz Albe and Tom Lane, per an anonymous docs comment
Discussion: https://postgr.es/m/158399487096.5708.10696365251766477013@wrigleys.postgresql.org
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/xfunc.sgml | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index db8da53677b..7856e39e3fa 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -2200,9 +2200,9 @@ PG_FUNCTION_INFO_V1(funcname); <para> In a version-1 function, each actual argument is fetched using a <function>PG_GETARG_<replaceable>xxx</replaceable>()</function> - macro that corresponds to the argument's data type. In non-strict + macro that corresponds to the argument's data type. (In non-strict functions there needs to be a previous check about argument null-ness - using <function>PG_ARGNULL_<replaceable>xxx</replaceable>()</function>. + using <function>PG_ARGISNULL()</function>; see below.) The result is returned using a <function>PG_RETURN_<replaceable>xxx</replaceable>()</function> macro for the return type. @@ -2367,14 +2367,6 @@ CREATE FUNCTION concat_text(text, text) RETURNS text </para> <para> - At first glance, the version-1 coding conventions might appear to be just - pointless obscurantism, over using plain <literal>C</> calling - conventions. They do however allow to deal with <literal>NULL</>able - arguments/return values, and <quote>toasted</quote> (compressed or - out-of-line) values. - </para> - - <para> The macro <function>PG_ARGISNULL(<replaceable>n</>)</function> allows a function to test whether each input is null. (Of course, doing this is only necessary in functions not declared <quote>strict</>.) @@ -2389,6 +2381,14 @@ CREATE FUNCTION concat_text(text, text) RETURNS text </para> <para> + At first glance, the version-1 coding conventions might appear + to be just pointless obscurantism, compared to using + plain <literal>C</literal> calling conventions. They do however allow + us to deal with <literal>NULL</literal>able arguments/return values, + and <quote>toasted</quote> (compressed or out-of-line) values. + </para> + + <para> Other options provided by the version-1 interface are two variants of the <function>PG_GETARG_<replaceable>xxx</replaceable>()</function> |