date:20130626

[Haskell-cafe] Geometric Algebra [Was: writing a function to make a correspondance between type-level integers and value-level integers]

2013-06-26 Thread oleg


 It seems very interesting, but I have not currently the time to make a 
 detailed comparison with vector/tensor algebra. Moreover I have not 

I would suggest the freely available
Oersted Medal Lecture 2002
by David Hestenes
http://geocalc.clas.asu.edu/pdf/OerstedMedalLecture.pdf
the person who discovered and developed the Geometric Algebra.

In particular, see Section V of the above paper. It talks about
vectors, geometric products, the coordinate-free representation for
`vector product' and the geometric meaning of the imaginary unit i.
Section 1 gives a good motivation for the Geometric Algebra. Other
sections of the paper develop physical applications, from classical
mechanics to electrodynamics to non-relativistic and relativistic
quantum mechanics.

Computer Scientists might then like
http://www.geometricalgebra.net/
see the good and free introduction
http://www.geometricalgebra.net/downloads/ga4cs_chapter1.pdf

Incidentally, David Hestenes said in the lecture that he has applied
for an NSF grant to work on Geometric Algebra TWELVE times in a row,
and was rejected every single time.




___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] homotopy type theory for amateurs

2013-06-26 Thread Ben

hello cafe --

i have created the mailing list hott-amate...@googlegroups.com

https://groups.google.com/d/forum/hott-amateurs

(perhaps forever consigning myself to spam folders everywhere.)  if you are 
interested in joining this reading group, you can do so there.  nothing has 
been decided yet on how it is to be run.

best, b

On Jun 25, 2013, at 1:03 PM, Ben wrote:

 hello cafe --
 
 by now i'm sure you have heard that the homotopy type theory folks have just 
 written up a free introductory book on their project.
 
 http://homotopytypetheory.org/2013/06/20/the-hott-book/
 
 gabriel gonzalez and i are starting up a small reading group for the book.  
 the level of study will be amateur, though i have high hopes for rigor and 
 thoroughness.  personally, i know hardly any type theory or logic, and the 
 last time i thought about homotopy theory in any seriousness was years ago.  
 thankfully the book looks very accessible.  being time-constrained we were 
 going to do it mostly over email, maybe starting a google group or other 
 mailing list, but we might meet as well, say once a month in san francisco 
 (where we both are.)
 
 if you're interested in joining us, send me an email (midfield at gmail) and 
 i'll try to keep you informed of any developments.
 
 best, ben
 


___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] Annotation problem after HP reinstalation

2013-06-26 Thread Vlatko Basic

I uninstalled haskell-platform, deleted .cabal and .ghc dirs and reinstalled it 
(on Ubuntu), but now the annotation (and other annotations)


{-# ANN module HLint: ignore Eta reduce #-}

produces error

Ambiguous type variable `a0' in the constraints:
  (Data a0) arising from an annotation at src/Model.hs:82:1-45
  (Data.String.IsString a0)
arising from the literal `HLint: ignore Eta reduce'
at src/Model.hs:82:16-41
Probable fix: add a type signature that fixes these type variable(s)
In the expression: HLint: ignore Eta reduce
In the annotation: {-# ANN module HLint: ignore Eta reduce #-}


Have I missed to install/configure something?

vlatko

___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Annotation problem after HP reinstalation

2013-06-26 Thread Sturdy, Ian

Looks to me as if you have OverloadedStrings enabled somewhere, in which case 
that would be the correct behaviour.

IRS


From: haskell-cafe-boun...@haskell.org [haskell-cafe-boun...@haskell.org] on 
behalf of Vlatko Basic [vlatko.ba...@gmail.com]
Sent: Wednesday, June 26, 2013 11:05 AM
Cc: Haskell-Cafe
Subject: [Haskell-cafe] Annotation problem after HP reinstalation

I uninstalled haskell-platform, deleted .cabal and .ghc dirs and reinstalled it
(on Ubuntu), but now the annotation (and other annotations)

{-# ANN module HLint: ignore Eta reduce #-}

produces error

Ambiguous type variable `a0' in the constraints:
   (Data a0) arising from an annotation at src/Model.hs:82:1-45
   (Data.String.IsString a0)
 arising from the literal `HLint: ignore Eta reduce'
 at src/Model.hs:82:16-41
 Probable fix: add a type signature that fixes these type variable(s)
 In the expression: HLint: ignore Eta reduce
 In the annotation: {-# ANN module HLint: ignore Eta reduce #-}


Have I missed to install/configure something?

vlatko

___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe



___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Annotation problem after HP reinstalation

2013-06-26 Thread Vlatko Basic


Hi Ian,

Yes, seems that was the case. (But I had the feeling it was OK before the 
reinstallation.)


How to disable/ignore HLint suggestions if OverloadedStrings are used?


 Original Message  
Subject: Re: [Haskell-cafe] Annotation problem after HP reinstalation
From: Sturdy, Ian sturdy...@mail.wlu.edu
To: Haskell-Cafe haskell-cafe@haskell.org
Date: 26.06.2013 17:38


Looks to me as if you have OverloadedStrings enabled somewhere, in which case 
that would be the correct behaviour.

IRS


From: haskell-cafe-boun...@haskell.org [haskell-cafe-boun...@haskell.org] on 
behalf of Vlatko Basic [vlatko.ba...@gmail.com]
Sent: Wednesday, June 26, 2013 11:05 AM
Cc: Haskell-Cafe
Subject: [Haskell-cafe] Annotation problem after HP reinstalation

I uninstalled haskell-platform, deleted .cabal and .ghc dirs and reinstalled it
(on Ubuntu), but now the annotation (and other annotations)

{-# ANN module HLint: ignore Eta reduce #-}

produces error

Ambiguous type variable `a0' in the constraints:
(Data a0) arising from an annotation at src/Model.hs:82:1-45
(Data.String.IsString a0)
  arising from the literal `HLint: ignore Eta reduce'
  at src/Model.hs:82:16-41
  Probable fix: add a type signature that fixes these type variable(s)
  In the expression: HLint: ignore Eta reduce
  In the annotation: {-# ANN module HLint: ignore Eta reduce #-}


Have I missed to install/configure something?

vlatko

___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe



___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe



___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Remove Enum from Float and Double

2013-06-26 Thread Doug McIlroy

   it's the entire Enum class which doesn't have a consistent or sensible 
  semantics

Yes, for a language with generally sound mathematical roots, Enum is
an embarrassment. My pet peeve is that Rationals are enumerable, but
not with Enum. And the differing lengths of [1,4..6] and [1.0,4.0..6.0]
will shock even the non-mathematically inclined.

Much of the craziness can be hidden if in place of [a..b] for
nonintegral numeric types, one uses (map fromInteger [a..b]).
Perhaps that should happen automatically.

As for the horror mentioned at the end of the first paragraph,
the language definition's oafish attempt to get right things
like [0.0,0.1..1.0] needs major revision.

Doug McIlroy

___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] Haskell Weekly News: Issue 271

2013-06-26 Thread Daniel Santa Cruz

Welcome to issue 271 of the HWN, an issue covering crowd-sourced bits
of information about Haskell from around the web. This issue covers the
week of June 9 to 11, 2013.

Quotes of the Week

   * cmccann: also please note that malign remains one of my best
 function names ever

   * dolio: Peak file descriptors is a myth.

   * mami: i think my brain rewired for higher typesystem compatibility
 in my sleep

   * elliott: it's impure but only depending on the environment! which
 is to say it is impure.

   * johnw: lens makes one into a mutating ninja

   * applicativ: een my language we say Z for one

   * DavidJacobs: Code is like poetry; most of it shouldn't have been
 written.

   * merijn: If I could program with arbitrary real world side effects
 I'd use unsafeStabComputerUser if someone attempted that

   * shachaf: Hackage going down regularly is part of the rustic charm
 of Haskell!

   * shachaf: JavaScript is the best example of a domain-specific
 language. Because of the same-origin policy.

   * chrisdone: [on being invited to help with idris development] dude
 i've already got 20 yaks lined up waiting to be shaved, don't send
 me a whole truck full

   * shachaf: edwardk isn't benevolent or malevolent. edwardk is more of
 a simple mechanical process tending toward maximal complexity.

   * AndrejBauer: When have you ever heard a category theorist say: I
 want to prove this diagram commutesâLet's suppose it doesn't.

Top Reddit Stories

   * Applicative = Monad is coming.
 Domain: haskell.org, Score: 122, Comments: 62
 On Reddit: [1] http://goo.gl/JCvQ4
 Original: [2] http://goo.gl/fJxeX

   * The Homotopy Type Theory Book is now available for free online and in
print at Lulu.com
 Domain: homotopytypetheory.org, Score: 86, Comments: 16
 On Reddit: [3] http://goo.gl/x8nLW
 Original: [4] http://goo.gl/DR9gf

   * Three useful monads
 Domain: adit.io, Score: 71, Comments: 25
 On Reddit: [5] http://goo.gl/WHqPr
 Original: [6] http://goo.gl/1r8nC

   * Beta sign up for FP Complete new IDE
 Domain: fpcomplete.com, Score: 63, Comments: 11
 On Reddit: [7] http://goo.gl/RPV0P
 Original: [8] http://goo.gl/c03Od

   * HLearn implements more with 6 trivial lines of Haskell than Weka
implements with over 100 complex lines of Java
 Domain: izbicki.me, Score: 47, Comments: 9
 On Reddit: [9] http://goo.gl/EEqwS
 Original: [10] http://goo.gl/Ukk4E

   * Top secret School of Haskell articles leaked
 Domain: self.haskell, Score: 47, Comments: 17
 On Reddit: [11] http://goo.gl/zhhYm
 Original: [12] http://goo.gl/zhhYm

   * F-algebra tutorial
 Domain: fpcomplete.com, Score: 41, Comments: 35
 On Reddit: [13] http://goo.gl/Ybmbs
 Original: [14] http://goo.gl/szfGk

   * John Carmack on haskell today.
 Domain: self.haskell, Score: 40, Comments: 79
 On Reddit: [15] http://goo.gl/8qHkt
 Original: [16] http://goo.gl/8qHkt

   * Data Flow Fusion with Series Expressions in Haskell
 Domain: justtesting.org, Score: 40, Comments: 19
 On Reddit: [17] http://goo.gl/ZNeIP
 Original: [18] http://goo.gl/JAjjy

   * So you still don't understand Hindley-Milner? Part 1
 Domain: akgupta.ca, Score: 38, Comments: 0
 On Reddit: [19] http://goo.gl/OOk43
 Original: [20] http://goo.gl/SZ1Gb

   * Ask HN: Any downsides of programming in Haskell?
 Domain: news.ycombinator.com, Score: 36, Comments: 104
 On Reddit: [21] http://goo.gl/vRuHW
 Original: [22] http://goo.gl/fcleS

   * FP Complete - Haskell Introduction
 Domain: youtube.com, Score: 36, Comments: 12
 On Reddit: [23] http://goo.gl/GqgC5
 Original: [24] http://goo.gl/KoVYs

   * Fix your posture with haskell
 Domain: github.com, Score: 35, Comments: 2
 On Reddit: [25] http://goo.gl/lznTr
 Original: [26] http://goo.gl/x21Ax

   * preprint list for ICFP'13 papers (additional links welcome)
 Domain: github.com, Score: 34, Comments: 9
 On Reddit: [27] http://goo.gl/mZsTn
 Original: [28] http://goo.gl/bhbC9

   * GHC: now with closed type families
 Domain: github.com, Score: 34, Comments: 15
 On Reddit: [29] http://goo.gl/JJSSv
 Original: [30] http://goo.gl/QlV4s


Top StackOverflow Questions

   * How to compare two functions for equivalence, as in (λx.2*x) ==
(λx.x+x)?
 votes: 15, answers: 2
 Read on SO: [31] http://goo.gl/A6YDd

   * Should I use typeclasses or not?
 votes: 15, answers: 2
 Read on SO: [32] http://goo.gl/EOV1M

   * Is there something like `map2 :: (i - a) - (i - b) - [i] -
[(a,b)]`?
 votes: 11, answers: 2
 Read on SO: [33] http://goo.gl/WZyEy

   * Why isn't GeneralizedNewtypeDeriving a Safe Haskell?
 votes: 11, answers: 1
 Read on SO: [34] http://goo.gl/on6Fc

   * It's not a monad, but what is it?
 votes: 10, answers: 0
 Read on SO: [35] http://goo.gl/sm9gR

   * Writing efficient iterative loop for ST

[Haskell-cafe] Geometric Algebra [Was: writing a function to make a correspondance between type-level integers and value-level integers]

Re: [Haskell-cafe] homotopy type theory for amateurs

[Haskell-cafe] Annotation problem after HP reinstalation

Re: [Haskell-cafe] Annotation problem after HP reinstalation

Re: [Haskell-cafe] Annotation problem after HP reinstalation

Re: [Haskell-cafe] Remove Enum from Float and Double

[Haskell-cafe] Haskell Weekly News: Issue 271

7 matches

Site Navigation

Mail list logo

Footer information