hi. attached patch add function argument name to function substring and substr you can see the visual changes. mater behavior:
\df substring List of functions Schema | Name | Result data type | Argument data types | Type ------------+-----------+------------------+-------------------------+------ pg_catalog | substring | bit | bit, integer | func pg_catalog | substring | bit | bit, integer, integer | func pg_catalog | substring | bytea | bytea, integer | func pg_catalog | substring | bytea | bytea, integer, integer | func pg_catalog | substring | text | text, integer | func pg_catalog | substring | text | text, integer, integer | func pg_catalog | substring | text | text, text | func pg_catalog | substring | text | text, text, text | func with patch List of functions Schema | Name | Result data type | Argument data types | Type ------------+-----------+------------------+--------------------------------------------------+------ pg_catalog | substring | bit | bits bit, start integer | func pg_catalog | substring | bit | bits bit, start integer, count integer | func pg_catalog | substring | bytea | bytes bytea, start integer | func pg_catalog | substring | bytea | bytes bytea, start integer, count integer | func pg_catalog | substring | text | string text, pattern text | func pg_catalog | substring | text | string text, pattern text, escape_character text | func pg_catalog | substring | text | string text, start integer | func pg_catalog | substring | text | string text, start integer, count integer | func I did the same change to the function substr. since 9.7.2. SIMILAR TO Regular Expressions we use substring(string, pattern, escape-character) so i refactor the substring function argument name to substring(string text, pattern text, escape_character text). we can make it as ``substring(string text, pattern text, escape text).`` then in 9.7.2, we need to change the substring synopsis section. one thing I am not sure is about 9.4. String Functions and Operators Table 9.9. SQL String Functions and Operators. Do we need entries for substring related functions? current signature substring ( string text [ FROM start integer ] [ FOR count integer ] ) is kind of different from substring(string text, start integer, count integer). since the previous one can allow keywords "FROM", "FOR", the latter one won't.