Colors...

[cardalda]

Not really an issue, more a few improvements for colorization ;-)

Currently, I'm using the onigasm with vsdarkplus theme for pgplsql.
This is an example how my code looks like:

When I paste this in your playground; I get the following:

A few things caught my mind:

1. The "replace" part of "create or replace" is recognized as function rather than statement.
2. The word "begin" at the start of the function body should be colored as control flow
3. The column- and table names have no special meaning, so the default colorizer keeps them uncoloured. In your version, I do not see a difference. I would imagine that I can feed a data model to the language server in order to perform auto complete and may be to colorize them in a special color when the table name is recognized (as Dbeaver now does, see below)
4. I changed one rule in the original colorizer: I colorize words that start with an underscore with an alternate color. That's just a personal taste because I always declare variables with underscores to prevent ambiguity. You can see the effect in the "select ... into..." part.

dbeaver example:

[cardalda]

In the latest playground, even less tokens are recognized:

;

Here is the SQL so you can test it properly:

create or replace function version_bump (_oPar jsonb) returns jsonb as $$
declare
   _appl_id          int;
   _mode             varchar(10);
   _description      text;

   _major            int;
   _minor            int;
   _patch            int;
begin

  if(_oPar ? 'appl_id')      then _appl_id        =  _oPar ->  'appl_id';         end if;
  if(_oPar ? 'mode')         then _mode           =  _oPar ->> 'mode';            end if;
  if(_oPar ? 'description')  then _description    =  _oPar ->> 'description';     end if;

  if(_mode not in ('patch', 'minor', 'major')) then
    RAISE 'mode should be one of: "patch", "minor" or "major"' ;
  end if;

     select major
          , minor
          , patch
       into _major
          , _minor
          , _patch
       from app_versions        
      where appl_id = _appl_id
   order by vers_id desc
      limit 1
   ; 
end;
$$ language plpgsql;

One thing I forgot last time; the "jsonb" was not recognized as data type; in "returns jsonb", jsonb should be colored cyan.