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Add argument names to the regexp_XXX functions.

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This change allows these functions to be called using named-argument
notation, which can be helpful for readability, particularly for
the ones with many arguments.

There was considerable debate about exactly which names to use,
but in the end we settled on the names already shown in our
documentation table 9.10.

The citext extension provides citext-aware versions of some of
these functions, so add argument names to those too.

In passing, fix table 9.10's syntax synopses for regexp_match,
which were slightly wrong about which combinations of arguments
are allowed.

Jian He, reviewed by Dian Fay and others

Discussion: https://postgr.es/m/CACJufxG3NFKKsh6x4fRLv8h3V-HvN4W5dA=zNKMxsNcDwOKang@mail.gmail.com
This commit is contained in:
Tom Lane
2024-07-25 14:51:46 -04:00
parent 05faf06e9c
commit 580f8727ca
7 changed files with 112 additions and 32 deletions
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26
doc/src/sgml/func.sgml
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@ -3426,7 +3426,6 @@ SELECT NOT(ROW(table.*) IS NOT NULL) FROM TABLE; -- detect at least one null in
<primary>regexp_replace</primary>
</indexterm>
<function>regexp_replace</function> ( <parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type>, <parameter>replacement</parameter> <type>text</type>
[, <parameter>start</parameter> <type>integer</type> ]
[, <parameter>flags</parameter> <type>text</type> ] )
<returnvalue>text</returnvalue>
</para>
@ -3445,20 +3444,27 @@ SELECT NOT(ROW(table.*) IS NOT NULL) FROM TABLE; -- detect at least one null in
<row>
<entry role="func_table_entry"><para role="func_signature">
<function>regexp_replace</function> ( <parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type>, <parameter>replacement</parameter> <type>text</type>,
<parameter>start</parameter> <type>integer</type>,
<parameter>N</parameter> <type>integer</type>
[, <parameter>flags</parameter> <type>text</type> ] )
<parameter>start</parameter> <type>integer</type>
[, <parameter>N</parameter> <type>integer</type>
[, <parameter>flags</parameter> <type>text</type> ] ] )
<returnvalue>text</returnvalue>
</para>
<para>
Replaces the substring that is the <parameter>N</parameter>'th
match to the POSIX regular expression <parameter>pattern</parameter>,
or all such matches if <parameter>N</parameter> is zero; see
or all such matches if <parameter>N</parameter> is zero, with the
search beginning at the <parameter>start</parameter>'th character
of <parameter>string</parameter>. If <parameter>N</parameter> is
omitted, it defaults to 1. See
<xref linkend="functions-posix-regexp"/>.
</para>
<para>
<literal>regexp_replace('Thomas', '.', 'X', 3, 2)</literal>
<returnvalue>ThoXas</returnvalue>
</para>
<para>
<literal>regexp_replace(string=>'hello world', pattern=>'l', replacement=>'XX', start=>1, "N"=>2)</literal>
<returnvalue>helXXo world</returnvalue>
</para></entry>
</row>
@ -5963,7 +5969,7 @@ regexp_count('ABCABCAXYaxy', 'A.', 1, 'i') <lineannotation>4</lineannotation>
<programlisting>
regexp_instr('number of your street, town zip, FR', '[^,]+', 1, 2)
<lineannotation>23</lineannotation>
regexp_instr('ABCDEFGHI', '(c..)(...)', 1, 1, 0, 'i', 2)
regexp_instr(string=>'ABCDEFGHI', pattern=>'(c..)(...)', start=>1, "N"=>1, endoption=>0, flags=>'i', subexpr=>2)
<lineannotation>6</lineannotation>
</programlisting>
</para>
@ -6109,7 +6115,7 @@ SELECT col1, (SELECT regexp_matches(col2, '(bar)(beque)')) FROM tab;
The <function>regexp_replace</function> function provides substitution of
new text for substrings that match POSIX regular expression patterns.
It has the syntax
<function>regexp_replace</function>(<replaceable>source</replaceable>,
<function>regexp_replace</function>(<replaceable>string</replaceable>,
<replaceable>pattern</replaceable>, <replaceable>replacement</replaceable>
<optional>, <replaceable>start</replaceable>
<optional>, <replaceable>N</replaceable>
@ -6118,9 +6124,9 @@ SELECT col1, (SELECT regexp_matches(col2, '(bar)(beque)')) FROM tab;
(Notice that <replaceable>N</replaceable> cannot be specified
unless <replaceable>start</replaceable> is,
but <replaceable>flags</replaceable> can be given in any case.)
The <replaceable>source</replaceable> string is returned unchanged if
The source <replaceable>string</replaceable> is returned unchanged if
there is no match to the <replaceable>pattern</replaceable>. If there is a
match, the <replaceable>source</replaceable> string is returned with the
match, the <replaceable>string</replaceable> is returned with the
<replaceable>replacement</replaceable> string substituted for the matching
substring. The <replaceable>replacement</replaceable> string can contain
<literal>\</literal><replaceable>n</replaceable>, where <replaceable>n</replaceable> is 1
@ -6161,7 +6167,7 @@ regexp_replace('foobarbaz', 'b(..)', 'X\1Y', 'g')
<lineannotation>fooXarYXazY</lineannotation>
regexp_replace('A PostgreSQL function', 'a|e|i|o|u', 'X', 1, 0, 'i')
<lineannotation>X PXstgrXSQL fXnctXXn</lineannotation>
regexp_replace('A PostgreSQL function', 'a|e|i|o|u', 'X', 1, 3, 'i')
regexp_replace(string=>'A PostgreSQL function', pattern=>'a|e|i|o|u', replacement=>'X', start=>1, "N"=>3, flags=>'i')
<lineannotation>A PostgrXSQL function</lineannotation>
</programlisting>
</para>