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⬅️ Previous capture (2023-01-29)
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Since brev’s defines are just me hacking in matchable support in the define headers, and I didn’t know matchable that well at first, I’m always discovering new things that this means for brev’s define.
For example, it’s a match made in heaven when working with records.
(define-record horse leg-count name height) (define (leg-heightitude ($ horse leg-count name height)) (* leg-count height)) (map leg-heightitude (list (make-horse 4 'Tornado 58/12) (make-horse 8 'Sleipner 67/12)))
The first symbol after the dollar sign needs to be the record type, but then you can rename the slots; it goes by position, not name. You can omit unused trailing slots:
(define (label ($ horse lc n)) (conc n ", " lc "-legged horse"))
It’s still a generics define so you can define several different functions for polymorphic dispatch:
(define (label ($ bird name species)) (conc name " is a pretty bird")) (map label barrel-of-unsorted-animals)