heck is a case conversion library

"I specifically requested the opposite of this."

This library exists to provide case conversion between common cases like CamelCase and snake_case. It is intended to be unicode aware, internally consistent, and reasonably well performing.

Definition of a word boundary

Word boundaries are defined as the "unicode words" defined in the unicode_segmentation library, as well as within those words in this manner:

  1. All underscore characters are considered word boundaries.
  2. If an uppercase character is followed by lowercase letters, a word boundary is considered to be just prior to that uppercase character.
  3. If multiple uppercase characters are consecutive, they are considered to be within a single word, except that the last will be part of the next word if it is followed by lowercase characters (see rule 2).

That is, "HelloWorld" is segmented Hello|World whereas "XMLHttpRequest" is segmented XML|Http|Request.

Characters not within words (such as spaces, punctuations, and underscores) are not included in the output string except as they are a part of the case being converted to. Multiple adjacent word boundaries (such as a series of underscores) are folded into one. ("hello_world" in snake case is therefore "helloworld", not the exact same string). Leading or trailing word boundary indicators are dropped, except insofar as CamelCase capitalizes the first word.

Cases contained in this library:

  1. UpperCamelCase
  2. lowerCamelCase
  3. snake_case
  4. kebab-case
  5. SHOUTYSNAKECASE
  6. Title Case
  7. SHOUTY-KEBAB-CASE
  8. Train-Case

Contributing

PRs of additional well-established cases welcome.

This library is a little bit opinionated (dropping punctuation, for example). If that doesn't fit your use case, I hope there is another crate that does. I would prefer not to receive PRs to make this behavior more configurable.

Bug reports & fixes always welcome. :-)

MSRV

The minimum supported Rust version for this crate is 1.32.0. This may change in minor or patch releases, but we probably won't ever require a very recent version. If you would like to have a stronger guarantee than that, please open an issue.

License

heck is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT for details.