I'd say ... an algorithm of minimum requirements could do the trick here.
for example:
In reply to Re^4: Reverse regexp a regexp? (by an algorithm?)
by freakingwildchild
in thread Reverse regexp a regexp?
by freakingwildchild
| For: | Use: | ||
| & | & | ||
| < | < | ||
| > | > | ||
| [ | [ | ||
| ] | ] |