Steven D'Aprano <st...@pearwood.info> writes: > Sounds like a regular expression. Remember that computer science > theoretical regular expressions don't just match strings, they can > apply to any sequence of primitive values.
Good insight, thank you. > In your case, you only need two special tokens, match-one and > match-one-or-more (which may be like r'.' and r'.*'). It actually needs “one” and “zero-or-more”. Which does match your analogous regex ‘.’ and ‘.*’ patterns. > Otherwise, you can create your own sequence type and simple regex > engine (you only need two meta-items, [ONE and ZERO-OR-MORE]) to > perform equality tests. It may have to come to that. That's not such a problem, but: > You can't use a dict for the mapping, not unless you're smarter than > me, due to the requirement to hash the keys. Dang. It's the mapping that I really need to solve, I think. A mapping that has a custom “does this candidate match any existing key” and “return the value for this key” to defer to the matching behaviour described above. Are those the ‘__contains__’, ‘__getitem__’ methods? What actually is the API of a mapping type, that would need to be customised for this application? -- \ “If we listen only to those who are like us, we will squander | `\ the great opportunity before us: To live together peacefully in | _o__) a world of unresolved differences.” —David Weinberger | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
