[racket-users] on the name of a data structure

To me a binary tree can be defined like this. ;; A BinaryTree is either ;; - false OR ;; - (BinaryTree Anything BinaryTree BinaryTree) I built a data structure which looked like a tree, but I think it's different. What should this be called? I called it a blob since I didn't know what it

Re: [racket-users] Proper non-tail recursion?

On Fri, Apr 28, 2017 at 12:29 PM, Matthias Felleisen <matth...@ccs.neu.edu> wrote: >> On Apr 28, 2017, at 11:12 AM, Ben Greenman <benjaminlgreen...@gmail.com> >> wrote: >> >> On Fri, Apr 28, 2017 at 11:08 AM, Daniel Bastos <dbas...@toledo.com> wrot

Re: [racket-users] Proper non-tail recursion?

On Fri, Apr 28, 2017 at 11:19 AM, Matthias Felleisen wrote: > [...] Their implementors will argue that deep recursions don’t exist or > shouldn’t be supported. [...] Python's argument for not supporting tail-call optimization (if I should call it that way after this

Re: [racket-users] Is this a closure?

There's another sense of the word ``closure'' while still in the subject of computing but which is different from what you've understood so far. Your understanding and the sense of the word used by Matthias Felleisen and David Storrs is that of Peter Landin in 1964. In ``[t]he mechanical

Re: [racket-users] beautiful-racket, contract-violation: expected: module-path? given ('planet ....)

On Tue, Mar 21, 2017 at 5:28 PM, Alexis King wrote: > The unlib package is an old PLaneT package, so it won’t show up > when you run `raco pkg show`. It’s a dependency of the snooze package > (also from PLaneT), which you appear to have installed. Unfortunately, > the unlib

Re: [racket-users] beautiful-racket, contract-violation: expected: module-path? given ('planet ....)

On Tue, Mar 21, 2017 at 1:16 PM, John Clements wrote: > It looks to me as though this error may have nothing to do with beautiful > racket, and that beautiful racket may have installed successfully. > > In particular, it looks like an error occurred while building the

[racket-users] beautiful-racket, contract-violation: expected: module-path? given ('planet ....)

This was installed via DrRacket. The generated command line was: raco.exe pkg update --deps search-auto --scope user beautiful-racket See errors below. Thank you. Resolving "beautiful-racket" via https://download.racket-lang.org/releases/6.6/catalog/ Resolving "beautiful-racket" via

Re: [racket-users] racket-mode: OK to require Racket 6.0+?

I use it. I really like it. Go ahead! (And thank you!) On Mon, Oct 10, 2016 at 3:08 PM, Greg Hendershott wrote: > This is a heads-up that I want to update racket-mode for Emacs to > require Racket 6.0 or newer. [...] -- You received this message because you are

[racket-users] pkg collections: packages installed, although setup reported errors

​%raco pkg install collections Resolving "collections" via https://download.racket-lang.org/releases/6.6/catalog/ Resolving "collections" via https://pkgs.racket-lang.org Downloading repository git://github.com/lexi-lambda/racket-collections The following uninstalled packages are listed as

[racket-users] Re: on updating the aws package to api version 20120810

does adding new functionality like create-table-jsexpr > (but not breaking backward compatibility -- e.g. let's not remove > create-table or change the endpoint default.) > > In any case would you mind making a pull request at > https://github.com/greghendershott/aws please? That wo

[racket-users] on updating the aws package to api version 20120810

Thank you for writing the aws package. Currently, it supports the api version 20111205. I updated dynamo.rkt to use the newer api 20120810. I updated the tests as well. I touched only dynamo.rkt. (*) What did I change My needs began with create-table because the new api version changed

[racket-users] on the racket web server and the configure servlet

I'm investigating the Racket Web Server. It seems to me the default server-root-path is Racket/share/pkgs/web-server-lib/web-server/default-web-root/htdocs because I specified ``#:server-root-path "htdocs"'' and I saw the program was missing conf/ files and it gave away this directory above.

[racket-users] on solving linear systems by way of determinants

Dear Rackteers, I appreciate getting feedback on this small victory. I know so many come here asking for such things. So let me try to offer you something too. How about fun with history? Did you know that you could solve linear systems with mere determinant computation? I didn't! After

[racket-users] on module: identifier already imported from a different source

I'm getting module: identifier already imported from a different source when I require these two modules. (require math/number-theory) (require racket/list) I want factorize from math/number-theory and remove-duplicates from racket/list. I've seen old messages about this error, but they seemed

[racket-users] htdp/2e: exercises 336-338, feedback desired and questions

​​ Exercise 336. Is (bundle abc 0) a proper use of the bundle function? What does it produce? Why? ​Solution. It's not a proper use. It produces nothing. It doesn't terminate. Because (drop ls 0)​ returns a list not smaller than ls, hence the recursion of bundle doesn't reach the base case. I