[racket] Why functional?

I posted the following question at stackoverflow and got 3 pluses and a star (favorite question) -- although only one response. I'd really like to clear these issues up in my mind. Here goes: I've read some of the discussions here, as well as followed links to other explanations, but I'm sti

[racket] Common Lisp or Racket?

I'm your typical newbie who is hand-wringing over what direction to go in the general functional programming world. Lisp, Scheme, or Haskell? Of late I've been trying to get through the Barski book, "Land of Lisp," but I'm really seeing now why Scheme was created: CL seems to have a ton of gnarl t

[racket] Purely Functional needs "One Memory/Massively Parallel"

Please correct me if I'm way off base, but the whole issue of a purely functional language being impractical because it should not "go outside" the function (e.g. for IO) seems to hinge on the fact that there is (today) a segmented, discrete, world out there where data and apis etc. reside outside

Re: [racket] (off) Purely Functional needs "One Memory/Massively Parallel"

rocessors." > > (2) I think FP can deal with I/O in a truly functional manner, but no, I > haven't seen an efficient implementation yet. > > > > > On Feb 5, 2014, at 11:48 AM, Lawrence Bottorff wrote: > > > Please correct me if I'm way off base, but t

[racket] racket install on NetBSD provider?

I just joined a shell provider (sdf.org) that's running 64bit-NetBSD. I want to install Racket to my local directory. Do I need just the raw source? LB Racket Users list: http://lists.racket-lang.org/users

[racket] Holzweg-PLAI. Not doable in DrRacket 6.0.1?

Not sure how to proceed with PLAI per http://cs.brown.edu/courses/cs173/2012/book/Introduction.html The code seems not to run, e.g., #lang plai (define-type MisspelledAnimal [caml (humps : number)] [yacc (height : number)]) actually wants to be (define-type MisspelledAnimal [caml (humps n

[racket] Python creep

The other day I took a look at the on-line university Udacity. I was impressed by the computer-oriented courses they offered . . . until I realized they are all based around Python . . . with no apparent way to substitute something like Racket. Udacity is a Python-only shop. I realize the choice o

[racket] Bootstrap teachpacks

Is there any documentation on how to set up and run Bootstrap lessons using DrRacket? For example, I'm trying through DrRacket to install the downloaded teachpack for Bootstrap and I get: default-load-handler: cannot open input file path: /home/borgauf/.racket/5.3.3/collects/installed-teachpacks

[racket-users] Science graphics with Racket?

I'd like to use Racket to generate scalable (svg?) graphics like gnuplot or GeoGebra does. For example, I'd like to create a cartesian coordinate graph system, then draw functions on it. One thing in particular would be to draw a graph of a circle based on the standard form of a circle, e.g., x^2 +

Re: [racket-users] Science graphics with Racket?

circle (pt 2 1) 3 ; center (2,1) >> radius 3 >> >> p ; show pict in repl >> >> (define (save-pict-as-svg p width height filename [exists 'replace]) >> (define dc (new svg-dc% >> [width width] >> [height h

[racket-users] racket in geiser (in Emacs): switch language in live REPL to plai-typed?

So, I can start a racket REPL in Emacs geiser. Then I can type (require typed/racket) and it seems to take, i.e., I'm ready to go with basic typed racket. This works as well from org-mode "babel" code blocks. Now I'd like to do the same with plai-typed -- so I can follow along with the PLAI boo

[racket-users] Racket module creation in org-mode?

Just wondering if creating a module always has to be based on a .rkt file? Would there be any way to create, say, modules (one or more) in an org-mode file, perhaps one module per babel code block? . . . Trying to get org-mode to be more "modular." -- You received this message because you are

[racket-users] Vector or array type for math vector?

I'm trying out some of the math capabilities of Racket and I'm guessing the linear algebra concept of a vector is actually an Array type in Racket, not a Vector. Is this correct? Racket's Vector is a data (as with Java's Vector) structure, right? -- You received this message because you are su

[racket-users] Using the graph library

I see the Racket Generic Graph Library, but I don't know how to use it. Where would one go to learn, tutorial-style" the ins and outs of using this library? I take it this library allows you to "roll your own" graph database? I did notice the HTDP has a section on graph things. Would this help?

Re: [racket-users] Using the graph library

On Saturday, October 29, 2016 at 3:06:18 PM UTC-4, jhemann wrote: > Stephen's talk at 4th Racketcon (https://www.youtube.com/watch?v=SvYJF5HC19w) > gave me a good tutorial-ish introduction.  > > > JBH > > > On Sat, Oct 29, 2016 at 8:59 PM, Lawrence Bottorff wrot

[racket-users] Literate program a math course with Racket?

I'm tackling SICP -- using Racket and Emacs/orgmode, which I think is the best combination (YMMV). I like SICP because it puts computational math in the mix of learning functional programming. Then Sussman did SICM (...Classical Mechanics; 2nd edition) -- which is way over my head. But again, it

[racket-users] Good Data Structures Book?

Can someone suggest a good text for data structures that would compatible with Racket? All I see are treatments using C/C++, Java, Python, i.e., the usual suspects. Or, how do you people at Racket-friendly/based universities teach undergrad data structures? -- You received this message because

[racket-users] Re: Good Data Structures Book?

On Wednesday, December 14, 2016 at 12:19:51 PM UTC-5, Prabhakar Ragde wrote: > > I am developing such a course for a spring term (May-August) offering at > the University of Waterloo (though it will probably use OCaml). There > does not appear to be an ideal textbook; I plan to synthesize materi

[racket-users] Racket graphics?

I've seen Racket graphics doing some basic graphics. How expressive is it? Could it do diagrams as well as TikZ or gnuplot? What output formats are there? Could it be like Processing and do 3-d and motion? -- You received this message because you are subscribed to the Google Groups "Racket Use

Re: [racket-users] Re: Racket graphics?

This is all very impressive, indeed. I was wondering if Racket could be used to create a new sort of GIS app, i.e., geographic information system. It would have to do "vector graphics," which is to say every primitive drawing object is real, i.e., isn't just a setup step toward creating a raster

Re: [racket-users] Re: Racket graphics?

> > What would be the novel aspect(s) of your GIS app? > Metadata is my main concern, and it's important in GIS and could be improved upon there -- IMHO. I get the impression from my research that the future of serious metadata is rooted in type theory and graph databasing, i.e, being able to

[racket-users] Typed Racket error in REPL but not when command-line-loaded

I'm looking at this from https://github.com/dparpyani/99-Lisp-Problems-in-Racket: #lang racket (require typed/racket) ;; Question: ;; Find the last box of a list. ;;Example: ;; (my-last '(a b c d)) ;; => '(d) ;; Consumes a list and returns the last element in it. (define (my-last lst

[racket-users] foldl reverses lists?

I see this: > (foldl cons '() '(1 2 3 4)) '(4 3 2 1) and have to conclude that foldl is reversing the list. This is bolstered by this: (define (my-reverse lst) (foldl cons empty lst)) which is a way of reversing a list. Good. But then I see this: (foldl (lambda (a b result) (begin

Re: [racket-users] foldl reverses lists?

Yes, thank you both for your help. -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://gro

[racket-users] Racket/Dr. Racket on Android?

Is there a version of Racket for Android yet? -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit

[racket-users] Is this a closure?

Looking at HTDP-1 (http://htdp.org/2003-09-26/Book/curriculum-Z-H-25.html#node_chap_19), I see this: (define (filter predicate alon) (cond [(empty? alon) empty] [else (cond [(predicate (first alon)) (cons (first alon) (filter predicate (rest alon)))

[racket-users] Lambda calculus done in Racket

I found these blowing down the sidewalk today ; TRUE = λx.λy.x (define mytrue (lambda (t) (lambda (f) t))) and ; FALSE = λx.λy.y (define myfalse (lambda (t) (lambda (f) f))) Two problems, I don't understand them and AFAICT, they don't work. I traced them back to this