PostgreSQL auto-slug / slugification field with trigger

gist.sql

create or replace function update_slug_from_name()
returns trigger as $$
begin
  new.slug = regexp_replace(
                regexp_replace(
                  regexp_replace(
                     lower(new.name),
                  '''', '', 'g'),
                '[^a-z0-9+]+', '-', 'g'),
             '^-+|-+$', '');
  return new;
end;
$$ language 'plpgsql';

create trigger update_slug before insert or update on things
for each row execute procedure update_slug_from_name();