## Summary
In a form like,
```clojure
(if condition :bg-white :bg-black)
```
`:bg-black` will fail to extract, while `:bg-white` is extracted as
expected. This PR fixes this case, implements more comprehensive
candidate filtering, and supersedes a previous PR.
Having recently submitted a PR for handling another special case with
Clojure keywords (the presence of `:` inside of keywords), I thought it
best to invert the previous strategy: Instead of handling special cases
one by one, consume keywords according to the Clojure reader spec.
Consume nothing else, other than strings.
Because of this, this PR is a tad more invasive rather than additive,
for which I apologize. The strategy is this:
- Strings begin with a `"` and ends with an unescaped `"`. Consume
everything between these delimiters (existing case).
- Keywords begin with `:`, and end with whitespace, or one out of a
small set of specific reserved characters. Everything else is a valid
character in a keyword. Consume everything between these delimiters, and
apply the class splitting previously contained in the outer loop. My
previous special case handling of `:` inside of keywords in #18338 is
now redundant (and is removed), as this is a more general solution.
- Discard _everything else_.
I'm hoping that a strategy that is based on Clojure's definition of
strings and keywords will pre-empt any further issues with edge cases.
Closes#18344.
## Test plan
- Added failing tests.
- `cargo test` -> failure
- Added fix
- `cargo test` -> success
---------
Co-authored-by: Jordan Pittman <jordan@cryptica.me>
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