* tokenizer-api: reduce Tokenizer overhead
Previously a new `Token` for each text encountered was created, which
contains `String::with_capacity(200)`
In the new API the token_stream gets mutable access to the tokenizer,
this allows state to be shared (in this PR Token is shared).
Ideally the allocation for the BoxTokenStream would also be removed, but
this may require some lifetime tricks.
* simplify api
* move lowercase and ascii folding buffer to global
* empty Token text as default
* enable tokenizer on json fields
enable tokenizer on json fields for type text
* Avoid making the tokenizer within the TextAnalyzer pub(crate)
* Moving BoxableTokenizer to tantivy.
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Co-authored-by: Paul Masurel <paul@quickwit.io>
closes#1766
Finding tantivy tokenizers is a frustrating experience currently, since
they need be updated for each tantivy version. That's unnecessary since
the API is rather stable anyway.
