[racket-users] ANN: with-cache

2016-11-22 Thread Ben Greenman
with-cache is a small package for saving the results of an expression to the filesystem #lang racket/base (require pict with-cache) (define (get-fish) (with-cache (cachefile "stdfish.rktd") (λ () (standard-fish 100 50 (get-fish) ;; Builds a fish (get-fish) ;; Reads a fish from

[racket-users] Contract on a parameter’s value as a function precondition?

2016-11-22 Thread Alexis King
I have a function that requires a parameter be set to a value satisfying a particular contract, but I don’t see any direct way to specify that constraint using the contract system. It seems possible to emulate using #:pre from ->* and ->i, but this has two problems: it doesn’t produce very good

Re: [racket-users] Re: What is the Racket equivalent to 'return' for early exit?

2016-11-22 Thread Ronie Uliana
Em segunda-feira, 21 de novembro de 2016 16:08:40 UTC-2, Leif Andersen escreveu: > Honestly, I personally like to use let/ec for this. I know it's still using > continuations, but it is much more lightweight, both syntactically and in > terms of run-time costs. > > (define (do-something) > >

Re: [racket-users] Racket backwards compatible to schemer books?

2016-11-22 Thread George Neuner
Hi Tim, On 11/18/2016 2:20 PM, Tim Johnson wrote: Hello racketeers : I retired as a coder. Now I can write in whatever programming language I wish to. I'd like to learn racket. I intend to start by working off of the Schemer books. I have the first three. Is racket fully compatible to the

Re: [racket-users] Racket backwards compatible to schemer books?

2016-11-22 Thread Sam Caldwell
I think there are some minor incompatibilities. For example, the seasoned schemer uses `letcc` whereas in racket you would write `let/cc`. I don't know if these are catalogued somewhere. - Sam Caldwell On Fri, Nov 18, 2016 at 2:20 PM, Tim Johnson wrote: > Hello racketeers

Re: [racket-users] Testing - mails sent from desktop mail client not received

2016-11-22 Thread Tim Johnson
* Tim Johnson [161118 13:02]: > I am sending this from my browser, pointed at > https://groups.google.com/forum/#!newtopic/racket-users as a test. > > Although I have been receiving emails sent to the Racket Users email list > (racket-users@googlegroups.com) as a

[racket-users] Racket backwards compatible to schemer books?

2016-11-22 Thread Tim Johnson
Hello racketeers : I retired as a coder. Now I can write in whatever programming language I wish to. I'd like to learn racket. I intend to start by working off of the Schemer books. I have the first three. Is racket fully compatible to the code in the schemer books? If not, is there a site

Re: [racket-users] Digest for racket-users@googlegroups.com - 10 updates in 1 topic

2016-11-22 Thread Ronie Uliana
I made this macro for exactly for the same reason :) https://gist.github.com/ruliana/80d7bb46225a22a3682711ca8bd11a1d @JohnClements, I guess you have a point :) but I think David is mostly talking about what we call "Guard Clauses" (