[racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Carl Eastlund
I would like the for/... comprehension macros to have #:while and #:until clauses similar to the #:when and #:unless clauses. I often find I want to short-circuit the sequence at some point, but there is no elegant way to do it. I could probably write sequence-while and sequence-until, but I

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Matthew Flatt
I think this is a good idea. The technique to implement it is embedded in `for/vector' (to handle a vector length), and I can generalize that and move it into `for...'. Also, I think the names `#:while' and `#:until' are too close to `#:when' and `#:unless'. I suggest `#:break-when' and

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Carl Eastlund
I agree that #:while and #:until are easily confused with #:when and #:unless. I slightly prefer #:stop- to #:break- as a prefix here, it seems a more natural word. I like the idea of allowing these clauses at the end of the body to give a notion of stopping after the current iteration. I had

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread J. Ian Johnson
+1 I've been using let/ec for this same functionality, and it's made me sad. -Ian - Original Message - From: Carl Eastlund c...@ccs.neu.edu To: Matthew Flatt mfl...@cs.utah.edu Cc: PLT Developers d...@lists.racket-lang.org Sent: Friday, September 14, 2012 11:49:20 AM GMT -05:00 US/Canada

Re: [racket-dev] What are single flonums good for?

2012-09-14 Thread John Clements
On Sep 12, 2012, at 1:03 PM, Jay McCarthy wrote: On Wed, Sep 12, 2012 at 8:31 AM, Neil Toronto neil.toro...@gmail.com wrote: Compatibility with C code? Why not have the FFI convert them? Save space? I can see that. It won't help much if they're sent to math library functions, though. Those

Re: [racket-dev] What are single flonums good for?

2012-09-14 Thread Robby Findler
As far as I can tell, if this pollutes TR programs in any interesting way, then it would be a cause for concern. Robby On Fri, Sep 14, 2012 at 12:21 PM, John Clements cleme...@brinckerhoff.org wrote: On Sep 12, 2012, at 1:03 PM, Jay McCarthy wrote: On Wed, Sep 12, 2012 at 8:31 AM, Neil

Re: [racket-dev] What are single flonums good for?

2012-09-14 Thread Eli Barzilay
Two hours ago, John Clements wrote: I haven't followed the conversation closely enough to understand the ramifications of the proposed change, though; my guess is that the ffi can still address such arrays, it's just that computing with these values will require coercion. I could be okay

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Eli Barzilay
5 hours ago, Carl Eastlund wrote: Has this been brought up before?  I can't recall.  Does anyone else run into the same issue? (I think that I brought this up when the comprehensions were first discussed, pointing at the similar tool I have in Swindle which makes implementing them very easy.)

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Robby Findler
My $0.02: I find #:while and #:when to be too close, and #:until and #:unless even closer. Robby On Fri, Sep 14, 2012 at 2:30 PM, Eli Barzilay e...@barzilay.org wrote: 5 hours ago, Carl Eastlund wrote: Has this been brought up before? I can't recall. Does anyone else run into the same

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Matthew Flatt
At Fri, 14 Sep 2012 15:30:22 -0400, Eli Barzilay wrote: Four hours ago, Matthew Flatt wrote: Also, I think the names `#:while' and `#:until' are too close to `#:when' and `#:unless'. I suggest `#:break-when' and `#:break-unless'. Compare: (for*/list ([j 2] [i 10] #:when (i . .

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread John Clements
On Sep 14, 2012, at 1:14 PM, Robby Findler wrote: My $0.02: I find #:while and #:when to be too close, and #:until and #:unless even closer. More bike-shedding: I agree. In response to eli: I find the difficulty of reading break-when to be an adequate cost to pay to highlight the difference

Re: [racket-dev] Short-circuiting comprehensions

2012-09-14 Thread Carl Eastlund
I like most of that and don't object to the rest, except for leaving out a version of #:break-unless. Especially because break is already a negative word. Just like #:unless (bad?) is more natural than #:when (not (bad?)), #:something (ok-to-continue?) is more natural than #:break (not

Re: [racket-dev] What are single flonums good for?

2012-09-14 Thread Jay McCarthy
TR doesn't support them anyways because there are only typed f64 vectors and not typed f32 vectors. Jay On Fri, Sep 14, 2012 at 11:28 AM, Robby Findler ro...@eecs.northwestern.edu wrote: As far as I can tell, if this pollutes TR programs in any interesting way, then it would be a cause for

[racket-dev] Optimization Coach suggestion / question

2012-09-14 Thread John Clements
I used the optimization coach for the first time today. First, a suggestion. I wrestled with it for about five minutes before I realized that it applied only to programs written in TR. An error message here would be *really* useful; I kept mousing over and clicking and unclicking things to get

Re: [racket-dev] Optimization Coach suggestion / question

2012-09-14 Thread John Clements
On Sep 14, 2012, at 4:50 PM, Vincent St-Amour wrote: At Fri, 14 Sep 2012 15:39:22 -0700, John Clements wrote: I used the optimization coach for the first time today. First, a suggestion. I wrestled with it for about five minutes before I realized that it applied only to programs written in

Re: [racket-dev] What are single flonums good for?

2012-09-14 Thread Robby Findler
The original message in this thread suggests that there is a type Single-Flonum and that it is making Neil wrangle his code to be careful about it. Robby On Fri, Sep 14, 2012 at 3:55 PM, Jay McCarthy jay.mccar...@gmail.com wrote: TR doesn't support them anyways because there are only typed f64