[racket] users Digest, Vol 109, Issue 71

Please take me off the list

Thanks

On Sun, Sep 28, 2014 at 6:58 PM,  <users-request at racket-lang.org> wrote:
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> Today's Topics:
>
>    1. Re: aws/glacier: credential scope (Greg Hendershott)
>    2. Re: aws/glacier: credential scope (Greg Hendershott)
>    3. Re: aws/glacier: credential scope (Norman Gray)
>    4. Re: aws/glacier: credential scope (Greg Hendershott)
>    5. Re: typed racket, filters, and polymorphism (Matthias Felleisen)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 28 Sep 2014 17:15:21 -0400
> From: Greg Hendershott <greghendershott at gmail.com>
> To: Jay McCarthy <jay at racket-lang.org>
> Cc: users at racket-lang.org
> Subject: Re: [racket] aws/glacier: credential scope
> Message-ID:
>         <CAGspUn2t_ZOaEAgM2PDvSJDrTZbw2aX0VO66QdqmXi6REjJcMQ at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
>> I clicked "update" on pkgs.racket-lang.org. But it seems to be slower
>> than usual to refresh. After it does, you can `raco pkg update aws` to
>> get the fix.
>
> Something seems wrong/stuck on pkgs.racket-lang.org. The top of the page says:
>
>   "update upload in progress: there may be inconsistencies below"
>
> It's been saying that for nearly an hour.
>
> In the past, clicking "update" would cause a successful refresh -- the
> package would get a red star indicating it's updated -- within a
> minute or two.
>
>
> ------------------------------
>
> Message: 2
> Date: Sun, 28 Sep 2014 17:17:32 -0400
> From: Greg Hendershott <greghendershott at gmail.com>
> To: Jay McCarthy <jay at racket-lang.org>
> Cc: users at racket-lang.org
> Subject: Re: [racket] aws/glacier: credential scope
> Message-ID:
>         <CAGspUn1tMRkaZjK30rvxg+aUS7wXG5L_XT=_toU5o0YBg0pV+A at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
>>> I clicked "update" on pkgs.racket-lang.org. But it seems to be slower
>>> than usual to refresh. After it does, you can `raco pkg update aws` to
>>> get the fix.
>>
>> Something seems wrong/stuck on pkgs.racket-lang.org. The top of the page says:
>>
>>   "update upload in progress: there may be inconsistencies below"
>>
>> It's been saying that for nearly an hour.
>
> Sometimes instead it says:
>
>   "update upload being computed: the information below may not
> represent all recent changes and updates"
>
> It has switched between those two messages at various intervals over
> the last hour.
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 28 Sep 2014 22:40:19 +0100
> From: Norman Gray <norman at astro.gla.ac.uk>
> To: Greg Hendershott <greghendershott at gmail.com>
> Cc: Jay McCarthy <jay at racket-lang.org>, users at racket-lang.org
> Subject: Re: [racket] aws/glacier: credential scope
> Message-ID: <73617243-E0D5-43C6-872B-EA0121AD5142 at astro.gla.ac.uk>
> Content-Type: text/plain; charset=us-ascii
>
>
> On 2014 Sep 28, at 22:17, Greg Hendershott <greghendershott at gmail.com> wrote:
>
>>>> I clicked "update" on pkgs.racket-lang.org. But it seems to be slower
>>>> than usual to refresh. After it does, you can `raco pkg update aws` to
>>>> get the fix.
>>>
>>> Something seems wrong/stuck on pkgs.racket-lang.org. The top of the page says:
>>>
>>>  "update upload in progress: there may be inconsistencies below"
>>>
>>> It's been saying that for nearly an hour.
>>
>> Sometimes instead it says:
>>
>>  "update upload being computed: the information below may not
>> represent all recent changes and updates"
>>
>> It has switched between those two messages at various intervals over
>> the last hour.
>
> And in case it's a useful data point, I'm getting
>
> % raco pkg update aws
> Resolving "aws" via http://download.racket-lang.org/releases/6.1/catalog/
> Resolving "aws" via http://pkgs.racket-lang.org
> No updates available
> %
>
> And Greg, your fix is close enough to what I guessed might be the problem that I'm now kicking myself for not just diving in and trying a fix myself.  Garhhhh...
>
> Norman
>
>
> --
> Norman Gray  :  http://nxg.me.uk
> SUPA School of Physics and Astronomy, University of Glasgow, UK
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Sun, 28 Sep 2014 18:10:55 -0400
> From: Greg Hendershott <greghendershott at gmail.com>
> To: Norman Gray <norman at astro.gla.ac.uk>
> Cc: users at racket-lang.org
> Subject: Re: [racket] aws/glacier: credential scope
> Message-ID:
>         <CAGspUn2cc44ouZpTmvu8e6nW_EmtjWNccco6WoH5p2QuU=4zTQ at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> If you're in a hurry you could remove and re-install directly from GitHub:
>
>  $ raco pkg remove aws
>  $ raco pkg install git://github.com/greghendershott/aws
>
> On Sun, Sep 28, 2014 at 5:40 PM, Norman Gray <norman at astro.gla.ac.uk> wrote:
>>
>> On 2014 Sep 28, at 22:17, Greg Hendershott <greghendershott at gmail.com> wrote:
>>
>>>>> I clicked "update" on pkgs.racket-lang.org. But it seems to be slower
>>>>> than usual to refresh. After it does, you can `raco pkg update aws` to
>>>>> get the fix.
>>>>
>>>> Something seems wrong/stuck on pkgs.racket-lang.org. The top of the page says:
>>>>
>>>>  "update upload in progress: there may be inconsistencies below"
>>>>
>>>> It's been saying that for nearly an hour.
>>>
>>> Sometimes instead it says:
>>>
>>>  "update upload being computed: the information below may not
>>> represent all recent changes and updates"
>>>
>>> It has switched between those two messages at various intervals over
>>> the last hour.
>>
>> And in case it's a useful data point, I'm getting
>>
>> % raco pkg update aws
>> Resolving "aws" via http://download.racket-lang.org/releases/6.1/catalog/
>> Resolving "aws" via http://pkgs.racket-lang.org
>> No updates available
>> %
>>
>> And Greg, your fix is close enough to what I guessed might be the problem that I'm now kicking myself for not just diving in and trying a fix myself.  Garhhhh...
>>
>> Norman
>>
>>
>> --
>> Norman Gray  :  http://nxg.me.uk
>> SUPA School of Physics and Astronomy, University of Glasgow, UK
>>
>
>
> ------------------------------
>
> Message: 5
> Date: Sun, 28 Sep 2014 18:58:20 -0400
> From: Matthias Felleisen <matthias at ccs.neu.edu>
> To: "Alexander D. Knauth" <alexander at knauth.org>
> Cc: Spencer florence <spencerflorence at gmail.com>, racket users list
>         <users at racket-lang.org>, Sam Tobin-Hochstadt <samth at cs.indiana.edu>
> Subject: Re: [racket] typed racket, filters, and polymorphism
> Message-ID: <2B2B37BB-377F-4D28-8E69-EFEFCF8181A2 at ccs.neu.edu>
> Content-Type: text/plain; charset="utf-8"
>
>
> If you want the type checker to ensure your program is unit-correct, I assume you also want no run-time residual of the dimensions but that is in conflict with wanting a structure because it imposes a run-time cost. Are you sure you want a unit? -- Matthias
>
>
>
>
>
>
> On Sep 28, 2014, at 1:37 PM, Alexander D. Knauth wrote:
>
>> 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 <spencerflorence at gmail.com> 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 <alexander at knauth.org> 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 <samth at cs.indiana.edu> 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
>>> > <alexander at knauth.org> 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 <alexander at knauth.org>
>>> >> 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 <samth at cs.indiana.edu>
>>> >> 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
>>> >> <alexander at knauth.org> 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
>>> >>
>>> >>
>>> >>
>>> >> ____________________
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>>> >> http://lists.racket-lang.org/users
>>> >>
>>> >>
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>>> >> http://lists.racket-lang.org/users
>>> >>
>>> >>
>>>
>>>
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>>
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