Add support for Metamorph wildcards.

[blackwinter]

Delegates Value.Hash retrieval to SimpleRegexTrie for pattern matching.

All operations involving field patterns must be translated to concrete field names.

NOTE: Requires (a lot) more tests. But existing tests, including previously disabled ones, are already providing some coverage - with trivial (?) modifications to make them pass (not sure why they were testing the wrong order).

Resolves #89.

[blackwinter]

The bulk of the effort went into transformFields(). There may still be some pitfalls left.

[blackwinter]

Also, transformFields() and find()/findNested() are basically performing the same traversal operations. There may be room for consolidation.

[fsteeg]

Ah, nice, so we're using the trie for pattern matching only, not for storing the actual values. I was expecting this to require a larger change, but this looks very good 👍

Is my understanding correct that right now, we're creating a new trie with a single value for every lookup? I think we could make the trie a member of Hash to avoid multiple instantiations.

I think the wrong order in the disabled tests was from a previous state, where we were not using LinkedHashMap for the record map.

[blackwinter]

Is my understanding correct that right now, we're creating a new trie with a single value for every lookup? I think we could make the trie a member of Hash to avoid multiple instantiations.

Yes, your understanding is correct - and yes, we might be able to make it a member. I had a (hypothetical) case where that would've failed, but that might've been before I started checking for the actual pattern (trie.get(field).contains(pattern) instead of !trie.get(field).isEmpty()). I'll think about it a little more.

[blackwinter]

Alright, I've changed the trie to a member (432ef88). Should be fine™ ;)

[blackwinter]

Ah, nice, so we're using the trie for pattern matching only, not for storing the actual values.

FTR, we can't use SimpleRegexTrie as a key/value store because it's meant for the reverse use case as a Registry for NamedValueReceivers: It stores patterns (Metamorph lookups) and then retrieves values by concrete field name (metadata stream).