I have always found writing loops in Bash to be fickle, tedious, and needlessly complicated.

`loop` allows you to write intuitive, powerful looping one liners, with many useful features like breaking on pattern matching, timed loops, and loops for a specific duration.

For instance, to try a thing until it succeeds, every 15 seconds, for a maximum of five times in Bash:

    n=0
    until [ $n -ge 5 ]
    do
       do_thing.sh && break
       n=$[$n+1]
       sleep 15
    done

becomes:

    loop './do_thing.sh' --every 15s --until-success --num 5    

This was also my first Rust project, so feedback is welcome!