Crate heck

heck is a case conversion library.

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 by non-alphanumeric characters, as well as within those words in this manner:

1. If an uppercase character is followed by lowercase letters, a word boundary is considered to be just prior to that uppercase character.
2. 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 1).

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 “hello_world”, 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. SHOUTY_SNAKE_CASE
6. Title Case
7. SHOUTY-KEBAB-CASE
8. Train-Case