Re: Safe pattern matching

[Ian Price]

Nikita Karetnikov <address@hidden> writes:

> How would you rewrite the following function in Guile?
>
> foo :: [Int] -> String -> [Int]
> foo (x:y:ys) "+" = (x + y):ys
> foo (x:y:ys) "-" = (x - y):ys
> foo xs       num = read num:xs

Daniel covered most of this already, but instead you might consider
(define foo
  (match-lambda* ....))
rather than
(define (foo . args)
   (match args
     ....))

the nearest analogue to read is object->string, but it is not a generic.

-- 
Ian Price -- shift-reset.com

"Programming is like pinball. The reward for doing it well is
the opportunity to do it again" - from "The Wizardy Compiled"