[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

[racket-users] Trying to understand racket/gui and racket/draw

How do I draw into a canvas and have the results persist past the next call to paint-callback? Given the code below I was expecting to see: 1) A window opens with a diagonal green line on it 2) A vertical blue line appears, crossing with the green line 3) The window goes fullscreen, still

[racket-users] Black Swan Learning needs Racketeers

Inspired by the Global Learning XPRIZE, Black Swan Learning http://BlackSwanLearning.com is developing tablet-based software to help kids learn the Foundational Literacies: reading, writing, arithmetic, and systems thinking. In our research we have discovered learning methods we call “black

Re: [racket-users] Target is not an object, target #f for get-client-size

Can you send me a program to run and remind me which platform you're using? This must be a bug at some level below your code, because `this` should never be `#f`. I expect that the problem is in the binding to the native GUI library, where it's incorrectly allowing a callback too early. At Thu,

[racket-users] Target is not an object, target #f for get-client-size

I have a subclass of list-box% which overrides on-size and calculates relative column sizes based on get-client-size and some values provided by an init variable. However, if I don't check for "this" being an object, I get: send: target is not an object target: #f method name:

Re: [racket-users] Re: bug in web-server bindings parsing of filenames with quotes?

> On Sep 14, 2016, at 6:27 PM, Jay McCarthy wrote: > > Yes, this is an error. Line 251 of web-server/http/request.rkt uses a > regular-expression to extract the name and it is not robust against > quoted strings. I don't have the bandwidth to fix this until after >