2016-01-29 23:12 GMT+01:00 Jean-Michel HUFFLEN <[email protected]>:
> Jens Axel Søgaard <[email protected]> wrote: > > 2016-01-28 21:48 GMT+01:00 jmhuffle <[email protected]>: >> >> Dear Racket friends, >>> >>> I am surprised because the following code works in "lang racket", but >>> not in R6RS: in this last case, I got a contract violation for the value >>> associated with "alignment within the horizontal panel. Is there a way to >>> include such a horizontal panel in a program using R6RS, please? >>> (...) >>> >> In R6RS '(left top) will allocate a list consisting of mutable cons cells. >> In Racket '(left top) will allocate a list of immutable cons cells. >> > > OK, thanks. But a point is still obscure, for me. In R6RS, if the > library "mutable-pairs" is not used, lists are supposed to be immutable, > aren't they? So, they are immutable because we cannot use "set-car!" and > "set-cdr!", provided by this library, but they are not "immuable enough" > for Racket's graphical objects... Strange... > > Sorry - I am stuck back in R4RS/R5RS times where Scheme only had mutable lists. /Jens Axel -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
