bexpand

Bash-style brace expansion in Rust.

This does not 100% conform to Bash's style in the following ways:

There are patterns considered ill-formed and will throw an error in bexpand. It will not try to truck along if a bad pattern is found.
Braces are special characters and are not allowed without either being correctly formed or being escaped. In Bash a{b,c}d}e expands to abd}e acd}e and a{b{c,d}e expands to a{bce a{bde. In bexpand, both are errors.
Empty and single-component lists are considered acceptable in bexpand. In Bash, a{}b and a{b}c are both literally repeated by the shell. In bexpand, these expand to ab and abc.
bexpand allows character sequences to iterate any valid unicode codepoints. {🥰..🥴..2} is a valid character sequence, as is {\{..\.}, and {9..A}. Technically, {\0..\9} is valid as well, and will be treated as a character sequence, though it expands to the exact same thing as a numeric sequence of the same form. Anything that would generate an illegal unicode codepoint will generate an error.
The width specifier is done with an equal sign at the beginning of the opening brace instead, so in Bash, {001..100} is instead done in bexpand as {=1..100}. This is to allow things like {=-5..10}, which is impossible to express in Bash.

License

Published under the terms of the Mozilla Public License Version 2.0.