From d30592f190860cc68d08f956ac6853aa2c60e1bf Mon Sep 17 00:00:00 2001
From: jian he <jian.universality@gmail.com>
Date: Wed, 31 Dec 2025 15:26:31 +0800
Subject: [PATCH v10 1/2] Add argument names to the substr functions

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

No changes to the citext extension are required, since the citext data type does
not define a specialized substr function.

commitfest: https://commitfest.postgresql.org/patch/5524
Discussion: https://postgr.es/m/CACJufxHTBkymh06D4mGKNe1YfRNFN+gFBybmygWk=PtMqu00LQ@mail.gmail.com
---
 doc/src/sgml/func/func-binarystring.sgml | 4 ++--
 doc/src/sgml/func/func-string.sgml       | 4 ++--
 src/include/catalog/pg_proc.dat          | 4 ++++
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func/func-binarystring.sgml b/doc/src/sgml/func/func-binarystring.sgml
index b256381e01f..58051595126 100644
--- a/doc/src/sgml/func/func-binarystring.sgml
+++ b/doc/src/sgml/func/func-binarystring.sgml
@@ -571,11 +571,11 @@
         <indexterm>
          <primary>substr</primary>
         </indexterm>
-        <function>substr</function> ( <parameter>bytes</parameter> <type>bytea</type>, <parameter>start</parameter> <type>integer</type> <optional>, <parameter>count</parameter> <type>integer</type> </optional> )
+        <function>substr</function> ( <parameter>source</parameter> <type>bytea</type>, <parameter>start</parameter> <type>integer</type> <optional>, <parameter>count</parameter> <type>integer</type> </optional> )
         <returnvalue>bytea</returnvalue>
        </para>
        <para>
-        Extracts the substring of <parameter>bytes</parameter> starting at
+        Extracts the substring of <parameter>source</parameter> starting at
         the <parameter>start</parameter>'th byte,
         and extending for <parameter>count</parameter> bytes if that is
         specified.  (Same
diff --git a/doc/src/sgml/func/func-string.sgml b/doc/src/sgml/func/func-string.sgml
index 7ad1436e5f8..3325ade065a 100644
--- a/doc/src/sgml/func/func-string.sgml
+++ b/doc/src/sgml/func/func-string.sgml
@@ -1390,11 +1390,11 @@
         <indexterm>
          <primary>substr</primary>
         </indexterm>
-        <function>substr</function> ( <parameter>string</parameter> <type>text</type>, <parameter>start</parameter> <type>integer</type> <optional>, <parameter>count</parameter> <type>integer</type> </optional> )
+        <function>substr</function> ( <parameter>source</parameter> <type>text</type>, <parameter>start</parameter> <type>integer</type> <optional>, <parameter>count</parameter> <type>integer</type> </optional> )
         <returnvalue>text</returnvalue>
        </para>
        <para>
-        Extracts the substring of <parameter>string</parameter> starting at
+        Extracts the substring of <parameter>source</parameter> starting at
         the <parameter>start</parameter>'th character,
         and extending for <parameter>count</parameter> characters if that is
         specified.  (Same
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 60f7ce502f6..6c6f31f7043 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3718,6 +3718,7 @@
   prosrc => 'rtrim' },
 { oid => '877', descr => 'extract portion of string',
   proname => 'substr', prorettype => 'text', proargtypes => 'text int4 int4',
+  proargnames => '{source, start, count}',
   prosrc => 'text_substr' },
 { oid => '878', descr => 'map a set of characters appearing in string',
   proname => 'translate', prorettype => 'text', proargtypes => 'text text text',
@@ -3736,6 +3737,7 @@
   prosrc => 'rtrim1' },
 { oid => '883', descr => 'extract portion of string',
   proname => 'substr', prorettype => 'text', proargtypes => 'text int4',
+  proargnames => '{source, start}',
   prosrc => 'text_substr_no_len' },
 { oid => '884', descr => 'trim selected characters from both ends of string',
   proname => 'btrim', prorettype => 'text', proargtypes => 'text text',
@@ -6306,9 +6308,11 @@
   prosrc => 'bytea_substr_no_len' },
 { oid => '2085', descr => 'extract portion of string',
   proname => 'substr', prorettype => 'bytea', proargtypes => 'bytea int4 int4',
+  proargnames => '{source, start, count}',
   prosrc => 'bytea_substr' },
 { oid => '2086', descr => 'extract portion of string',
   proname => 'substr', prorettype => 'bytea', proargtypes => 'bytea int4',
+  proargnames => '{source, start}',
   prosrc => 'bytea_substr_no_len' },
 { oid => '2014', descr => 'position of substring',
   proname => 'position', prorettype => 'int4', proargtypes => 'bytea bytea',
-- 
2.34.1