On Sun, Apr 28, 2013 at 2:51 PM, Mark H Weaver <m...@netris.org> wrote:
> Panicz Maciej Godek <godek.mac...@gmail.com> writes: > > > I've traced something that is not entirely a bug, but which was a > > little surprise for me. It has to do with the extensions that guile > > provides to the Scheme language -- namely, uniform vectors and arrays. > > > > The (ice-9 match) module offers the syntax > > (match #(1 2 3) > > (#(a b c) > > (list a b c))) > > ;===> (1 2 3) > > > > However, none of the following behaves as one could expect: > > (match #u8(1 2 3) > > (#u8(a b c) > > (list a b c))) > > This can't work because a uniform numeric vector cannot hold symbols, so > #u8(a b c) cannot be represented in the source code. > > please note a b c binds to values and is not symbols as in the pmatch matcher or match quasiquoute patterns. So with the right binder this could work. > If you want generic accessors, I guess the array accessors are what you > want. Patches to extend the pattern matcher to handle arrays are > welcome :) Actually for ice-9 match we would like the upstream version to implement these concepts Try ask foof on irc #scheme if he accept a patch to implement this in a portable way or ask him if he thinks he could spend time on it! Only if we could accept a slow implementation of the matcher we can implement a general vector matcher by patching vector-ref etc. /Stefan
