At Fri, 21 Oct 2011 05:14:28 +0200, Shriram Krishnamurthi wrote: > Ryan, I noticed this seems to be a problem in full Racket as well: try > > #lang racket > > (define web-colors > (shared ([W (cons "white" G)] > [G (cons "grey" W)]) > W)) > > (rest web-colors) > > Robby privately wrote to say it should be regarded as a bug.
That is the correct behavior for `racket': `first' and `rest' work only on lists (according to `list?', which does not include "cyclic lists"). You can use `car' and `cdr' to access the parts of arbitrary pairs. I think `first' in ASL was intended to work on pairs, and the behavior was apparently changed by a well-meaning attempt to improve some error report. I'm not sure the old behavior is really the right thing, but we'll either fix the docs or we'll fix `first'. Meanwhile, you can use `car' and `cdr' in ASL. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
