Re: [Chicken-users] two procedures looking for a good home

[Alejandro Forero Cuervo]

> (define (key-on proc #!optional (comparator <))
>   ;; Define a comparator function for a sort. E.g. to sort a list of
>   ;; lists by their first items, using string-case-insensitive
>   ;; comparison: (sort lst (key-on first string-ci<?))
>   (lambda (a b) (comparator (proc a) (proc b))))

This sounds very similar to the under-documented cmp-key function in
the orders egg:

> (define (cmp-key cmp key)
>   (lambda args (apply cmp (map key args))))

The orders egg provides some convenience wrappers around this.

Any help documenting that egg would be appreciated. :-)

Alejo.
http://azul.freaks-unidos.net/