Please take me off the list Thanks
On Sun, Sep 28, 2014 at 2:08 PM, <[email protected]> wrote: > Send users mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.racket-lang.org/users/listinfo > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of users digest..." > > > [Racket Users list: > http://lists.racket-lang.org/users ] > > > Today's Topics: > > 1. Re: typed racket, filters, and polymorphism (Alexander D. Knauth) > 2. Help debugging a ffi crash (Eric Dobson) > 3. Re: [GENERAL] Off Topic: Anybody reading this via > news.gmane.org? (Adrian Klaver) > 4. Re: Help debugging a ffi crash (Matthew Flatt) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 28 Sep 2014 13:37:30 -0400 > From: "Alexander D. Knauth" <[email protected]> > To: Spencer florence <[email protected]> > Cc: racket users list <[email protected]>, Sam Tobin-Hochstadt > <[email protected]> > Subject: Re: [racket] typed racket, filters, and polymorphism > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > No because I want the unit to be a struct that has a dimension field, not a > symbol with various dimensions defined as unions of units. > I want the unit to be based on the dimension, not the other way around, so > that new units can be made that have the same dimension. > > I have something like the number+unit struct (I called it measure), but I?ll > work on more that after I have the unit struct figured out. > > On Sep 28, 2014, at 12:13 PM, Spencer florence <[email protected]> > wrote: > >> would something like this work? >> >> #lang typed/racket >> >> (struct (U) number+unit ([amount : Real] [unit : U])) >> >> (define-type Weight-Unit (U 'kg 'g 'mg '?g)) >> (define-type Weight (number+unit Weight-Unit)) >> (define-predicate weight? Weight) >> >> (: make-weight : Real Weight-Unit -> Weight) >> (define (make-weight n u) >> (number+unit n u)) >> >> (: +/weight : Weight Weight -> Weight) >> ;; something something needs unit conversion >> (define (+/weight w1 w2) >> (number+unit (+ (number+unit-amount w1) >> (number+unit-amount w1)) >> (number+unit-unit w1))) >> >> (+/weight (make-weight 1 'kg) (make-weight 1 'kg)) >> >> >> >> On Sun, Sep 28, 2014 at 11:03 AM, Alexander D. Knauth <[email protected]> >> wrote: >> >> Because the struct is representing a unit (kilograms, meters, seconds, >> etc.), and a unit has a dimension (mass, length, time, etc.) and I want the >> type-checker to be able to know what the dimension of a unit is so that the >> types of functions can specify the dimension that something should have. >> The real solution to this would probably be bounded polymorphism, but I was >> wondering if there was some other way to do it with occurrence typing in the >> guard or something like that. >> >> On Sep 28, 2014, at 11:48 AM, Sam Tobin-Hochstadt <[email protected]> >> wrote: >> >> > Why not do this with the type, instead of making this polymorphic? >> > >> > Sam >> > >> > On Fri, Sep 26, 2014 at 7:35 PM, Alexander D. Knauth >> > <[email protected]> wrote: >> >> Is it possible to have a struct that does certain things according to the >> >> guard? >> >> #lang typed/racket >> >> >> >> (struct (a) foo ([a : a]) #:transparent >> >> #:guard (lambda (a _) >> >> (unless (exact-integer? a) >> >> (error 'foo "expected Integer, given ~v" a)) >> >> a)) >> >> >> >> (ann (foo (ann 1 Any)) (foo Integer)) >> >> >> >> (: x : (foo Any)) >> >> (define x (foo 1)) >> >> >> >> (ann (foo-a x) Integer) >> >> >> >> ;. Type Checker: Polymorphic function `foo1' could not be applied to >> >> arguments: >> >> ;Argument 1: >> >> ; Expected: a >> >> ; Given: Any >> >> ; >> >> ;Result type: (foo a) >> >> ;Expected result: (foo Integer) >> >> ; in: (foo (ann 1 Any)) >> >> ;. Type Checker: Polymorphic function `foo-a' could not be applied to >> >> arguments: >> >> ;Argument 1: >> >> ; Expected: (foo a) >> >> ; Given: (foo Any) >> >> ; >> >> ;Result type: (a : ....) >> >> ;Expected result: Integer >> >> ; in: (foo-a x) >> >> >> >> On Sep 25, 2014, at 9:42 PM, Alexander D. Knauth <[email protected]> >> >> wrote: >> >> >> >> What I?m trying to accomplish is something more like this: >> >> #lang typed/racket >> >> >> >> (require "dimensions.rkt") >> >> >> >> (struct (d) unit ([name : Any] [scalar : Positive-Real] [dimension : d]) >> >> #:transparent >> >> #:guard (lambda (name scalar dimension _) >> >> (unless (dimension? dimension) >> >> (error 'unit "expected Dimension, given ~v" dimension)) >> >> (values name scalar dimension))) >> >> >> >> (define-type (Unitof d) (unit d)) >> >> >> >> (define-type Unit (Unitof Dimension)) >> >> >> >> (define Unit? (make-predicate Unit)) >> >> >> >> (define-type Unitish >> >> (U (Unitof Any) >> >> Dimension >> >> Positive-Real)) >> >> >> >> (: ->unit : (All (d) (case-> [(Unitof d) -> (Unitof d)] >> >> [Unitish -> Unit]))) >> >> (define (->unit u) >> >> (cond [(unit? u) >> >> (unless (Unit? u) ; this should never happen anyway because of the >> >> guard >> >> (error '->unit "expected (Unitof Dimension), given ~v" u)) >> >> u] >> >> [(dimension? u) (unit u 1 u)] >> >> [(positive-real? u) (unit u u dimensionless-dimension)])) >> >> >> >> >> >> On Sep 25, 2014, at 6:19 PM, Sam Tobin-Hochstadt <[email protected]> >> >> wrote: >> >> >> >> No, I don't think you can do this. Can you say more about what you're >> >> trying to accomplish? >> >> >> >> Sam >> >> >> >> On Thu, Sep 25, 2014 at 6:15 PM, Alexander D. Knauth >> >> <[email protected]> wrote: >> >> >> >> Do any of you have any advice for getting a function like this to >> >> type-check? >> >> #lang typed/racket >> >> >> >> (: check-int : (All (a) (case-> [a -> a] >> >> [Any -> Integer]))) >> >> (define (check-int int) >> >> (unless (exact-integer? int) >> >> (error 'check-int "expected Integer, given ~v" int)) >> >> int) >> >> >> >> ;. Type Checker: type mismatch >> >> ; expected: a >> >> ; given: Integer in: int >> >> >> >> >> >> >> >> ____________________ >> >> Racket Users list: >> >> http://lists.racket-lang.org/users >> >> >> >> >> >> ____________________ >> >> Racket Users list: >> >> http://lists.racket-lang.org/users >> >> >> >> >> >> >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users >> >> > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.racket-lang.org/users/archive/attachments/20140928/56742b6b/attachment-0001.html> > > ------------------------------ > > Message: 2 > Date: Sun, 28 Sep 2014 10:48:06 -0700 > From: Eric Dobson <[email protected]> > To: "[email protected]" <[email protected]> > Subject: [racket] Help debugging a ffi crash > Message-ID: > <caaehq5uru5v4i1rvnf6sdfcbqsd087ntcwftjrvhkronerm...@mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > I'm trying to debug an FFI crash that I'm seeing, and because it is > dealing with C code the error just presents as a segfault. I believe I > have tracked down what is causing the problem, but don't understand > how it could be doing so. > > I have two racket functions which take a "cursor" (the foreign > libraries object) and return a string representation of it, which I'm > trying to use for debugging. > > (define raw-clang-get-cstring > (get-ffi-obj "clang_getCString" lib-clang > (_fun _pointer -> _string))) > > (define raw-cursor-spelling > (get-ffi-obj "clang_getCursorSpelling" lib-clang > (_fun _CXCursor -> _pointer))) > > (define (cursor-spelling c) > (raw-clang-get-cstring (raw-cursor-spelling c))) > > (define cursor-spelling2 > (get-ffi-obj "clang_getCursorSpelling" lib-clang > (_fun _CXCursor -> (make-ctype _pointer values (? (v) > (raw-clang-get-cstring v)))))) > > If I use cursor-spelling, I have not been able to trigger a crash. But > if I use cursor-spelling2 I can reliably trigger a crash. > > Is there anything obvious on how these functions are different? > Because they look to me like they should be doing the same thing. If > it would be helpful I can try to get my code in a portable enough > shape so that it will work/crash on another machine. > > > > ------------------------------ > > Message: 3 > Date: Thu, 25 Sep 2014 17:25:15 -0700 > From: Adrian Klaver <[email protected]> > To: George Neuner <[email protected]>, [email protected] > Cc: "[email protected] >> users" <[email protected]> > Subject: Re: [racket] [GENERAL] Off Topic: Anybody reading this via > news.gmane.org? > Message-ID: <[email protected]> > Content-Type: text/plain; charset=windows-1252; format=flowed > > On 09/25/2014 05:13 PM, George Neuner wrote: >> >> On 9/25/2014 5:26 PM, Neil Van Dyke wrote: >>> You can check your IP addr against the list at >>> "http://gmane.org/denied.php";. >>> >>> Neil V. >> >> On 9/25/2014 7:08 PM, Adrian Klaver wrote: >>> >>> Take a look here: >>> >>> http://gmane.org/denied.php >>> >>> My guess is you are the fourth one from the bottom. >>> >>> >>> Might want to take a look at this thread to see what your options are >>> and what the turn around time is on your request: >>> >>> http://thread.gmane.org/gmane.discuss/16309 >> >> Thanks to both of you - I missed seeing the entry about the denied list >> in the FAQ. >> >> Adrian you were right - it seems that I have been blocked for some >> reason. Based on the description of infractions I really don't think I >> did anything to warrant it ... but there it is. I'll have to follow my >> lists by email until I can unblocked. > > I think the relevant part at gmane.org/denied.php is: > > "Since there is no way to identify users, news readers are denied on a > domain/IP basis. So if somebody on a machine close to you downloaded the > news spool yesterday, you're likely to be denied today" > >> >> Thanks again, >> George > > > -- > Adrian Klaver > [email protected] > > > ------------------------------ > > Message: 4 > Date: Sun, 28 Sep 2014 12:08:23 -0600 > From: Matthew Flatt <[email protected]> > To: Eric Dobson <[email protected]> > Cc: "[email protected]" <[email protected]> > Subject: Re: [racket] Help debugging a ffi crash > Message-ID: <[email protected]> > Content-Type: text/plain; charset=UTF-8 > > Looking at > > http://clang.llvm.org/doxygen/CXString_8h_source.html > > it seems that CXString as returned by clang_getCursorSpelling() is not > a pointer: > > typedef struct { > const void *data; > unsigned private_flags; > } CXString; > > If that's right, I'm a little surprised that `cursor-spelling` works > --- but when you get representation wrong, strange things can happen, > including something working when it shouldn't. > > Am I looking at the right library/definitions? > > At Sun, 28 Sep 2014 10:48:06 -0700, Eric Dobson wrote: >> I'm trying to debug an FFI crash that I'm seeing, and because it is >> dealing with C code the error just presents as a segfault. I believe I >> have tracked down what is causing the problem, but don't understand >> how it could be doing so. >> >> I have two racket functions which take a "cursor" (the foreign >> libraries object) and return a string representation of it, which I'm >> trying to use for debugging. >> >> (define raw-clang-get-cstring >> (get-ffi-obj "clang_getCString" lib-clang >> (_fun _pointer -> _string))) >> >> (define raw-cursor-spelling >> (get-ffi-obj "clang_getCursorSpelling" lib-clang >> (_fun _CXCursor -> _pointer))) >> >> (define (cursor-spelling c) >> (raw-clang-get-cstring (raw-cursor-spelling c))) >> >> (define cursor-spelling2 >> (get-ffi-obj "clang_getCursorSpelling" lib-clang >> (_fun _CXCursor -> (make-ctype _pointer values (? (v) >> (raw-clang-get-cstring v)))))) >> >> If I use cursor-spelling, I have not been able to trigger a crash. But >> if I use cursor-spelling2 I can reliably trigger a crash. >> >> Is there anything obvious on how these functions are different? >> Because they look to me like they should be doing the same thing. If >> it would be helpful I can try to get my code in a portable enough >> shape so that it will work/crash on another machine. >> >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users > > > > End of users Digest, Vol 109, Issue 69 > ************************************** ____________________ Racket Users list: http://lists.racket-lang.org/users
