Re: [Haskell-cafe] DSL for task dependencies

Speaking of which, for a while now I've been interested in designs of make-like systems that have precise & simple (denotational) semantics with pleasant properties. What Peter Landin called "denotative" (as opposed to functional-looking but semantically ill-defined or intractable). Norman Ramsey

[Haskell-cafe] How to contact OpenGL package maintainer (where is Sven?)

Hello, It looks like the OpenGL packages on hackage[1,2,3,4] have not been updated in some time. No updates later than Oct 2009. I tried to email Sven directly using the email address listed on hackage but after about a week I still haven't heard from him. I sent some patches to the opengl list

[Haskell-cafe] ghci Vim completion within Vim - need some advice

Hi, https://github.com/MarcWeber/vim-addon-async implements a hacky way to run external processes asynchronously. An external helper application send stdout of the process to Vim which adds the bytes to the buffer. Its not perfect but quite usable. Now I'd like to show the completion of \t sent

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

On Thu, Mar 17, 2011 at 6:41 PM, wren ng thornton wrote: > On 3/17/11 5:12 PM, Conor McBride wrote: > >> On 17 Mar 2011, at 18:35, wren ng thornton wrote: >> >>> Another question on particulars. When dealing with natural numbers, we >>> run into the problem of defining subtraction. There are a fe

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

On 3/17/11 5:12 PM, Conor McBride wrote: On 17 Mar 2011, at 18:35, wren ng thornton wrote: Another question on particulars. When dealing with natural numbers, we run into the problem of defining subtraction. There are a few reasonable definitions: No there aren't. How about "pragmatically ef

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

On 3/17/11 4:22 PM, Martin Escardo wrote: On 17/03/11 18:35, wren ng thornton wrote: (2) Use saturating subtraction, i.e. if the result would drop below zero then return zero; This is what people working with quantales do. Subtraction y-z, when it exists, is the solution in s to the equation

Re: [Haskell-cafe] X11 package bug: XClientMessageEvent long data

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 3/16/11 00:10 , Dylan Alex Simon wrote: > Does anyone know the current maintenance status of the X11 package? I emailed > Spencer Janssen a number of months ago and never heard back. So, I'll put > this here in case any one else runs into it or ca

Re: [Haskell-cafe] Defining subtraction for naturals

On 3/17/11 3:30 PM, David Menendez wrote: In "What About the Natural Numbers", Colin Runciman argues for [...] Thanks for the reference, I'll go check it out. -- Live well, ~wren ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.hask

Re: [Haskell-cafe] Byte Histogram

Right. So somebody else came up with an idea similar to mine, but since nobody could agree on anything more than a rough idea, nothing actually got done...(?) Well, I also got the sense that it would be more than a little nontrivial to implement. Or at least, someone was talking about how it wou

Re: [Haskell-cafe] Byte Histogram

On Thu, Mar 17, 2011 at 10:37 PM, Andrew Coppin wrote: > On 17/03/2011 12:11 PM, Gábor Lehel wrote: >> >> Necroing this thread because I just noticed there's a (rather old!) >> bug report which covers much of the same ground and doesn't seem to >> have been mentioned by anyone: >> >> http://hackag

Re: [Haskell-cafe] Wanted: composoable parsers from haskell-src-exts

> > I already export a partial parser for top-of-file pragmas, > > I see. What I don't see is how such a parser would return the "rest of input". Hmm. I see. And I see that you are correct in not seeing it, since it appears it cannot be done with Happy, which I believed. It would then be down to

Re: [Haskell-cafe] Byte Histogram

On 17/03/2011 12:11 PM, Gábor Lehel wrote: Necroing this thread because I just noticed there's a (rather old!) bug report which covers much of the same ground and doesn't seem to have been mentioned by anyone: http://hackage.haskell.org/trac/ghc/ticket/1349 Right. So somebody else came up with

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

On 17 Mar 2011, at 18:35, wren ng thornton wrote: Another question on particulars. When dealing with natural numbers, we run into the problem of defining subtraction. There are a few reasonable definitions: No there aren't. Conor ___ Haskell-C

Re: [Haskell-cafe] ANN: Monad.Reader special Poetry and Fiction Edition

I think we should have a wiki page somewhere which explains what all the various Haskell-related terms mean. Terms like "typing the knot" and "finally tagless". (Not to mention "Oleg rating"...) I have created such a page: http://www.haskell.org/haskellwiki/Terms Defining "unlifted type" witho

Re: [Haskell-cafe] How large is the Haskell community ?

On Thu, Mar 17, 2011 at 1:25 PM, Vo Minh Thu wrote: > Mm. Do 12000 lines of auto-generated code[0] count? > > Yes: The generator gets to be a member of the Haskell community! :-) - Mark ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www

Re: [Haskell-cafe] DSL for task dependencies

Hi Serge, You may be thinking of the Shake DSL presented by Neil Mitchell at last years Haskell Implementers Workshop. Slides and video are available from: http://haskell.org/haskellwiki/HaskellImplementorsWorkshop/2010 Max Bolingbroke has an open source implementation available here: https://

Re: [Haskell-cafe] How large is the Haskell community ?

2011/3/17 wren ng thornton : > On 3/17/11 9:18 AM, Andy Stewart wrote: >>> >>> On Sat, Feb 12, 2011 at 6:57 PM, Jan >>> Christiansen  wrote: >>> if you have written at least 1 lines of code in Haskell, > > Goodness. It looks like my current project is over 17,275 lines including > documentation

[Haskell-cafe] DSL for task dependencies

Hi Haskellers! I think I remember reading a blog post or web page describing a EDSL to describe tasks and their dependencies "a la" make. Can anyone point me to such published material? Thanks in advance. --serge ___ Haskell-Cafe mailing list Haskell

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

On 2011-03-17 19:35, wren ng thornton wrote: Dependently typed languages tend to use the second definition because it gives a pure total function (unlike the first) and because it's less obnoxious to use than the third. In Haskell the third would be even more obnoxious. There is a fourth option

Re: [Haskell-cafe] How large is the Haskell community ?

On 3/17/11 9:18 AM, Andy Stewart wrote: On Sat, Feb 12, 2011 at 6:57 PM, Jan Christiansen wrote: if you have written at least 1 lines of code in Haskell, Goodness. It looks like my current project is over 17,275 lines including documentation but excluding testing code (of which 2,557 are

Re: [Haskell-cafe] Defining subtraction for naturals

On Thu, Mar 17, 2011 at 2:35 PM, wren ng thornton wrote: > Another question on particulars. When dealing with natural numbers, we run > into the problem of defining subtraction. There are a few reasonable > definitions: > > (1) If the result would drop below zero then throw an overflow error; > >

Re: [Haskell-cafe] Defining subtraction for naturals

On Thu, 17 Mar 2011, wren ng thornton wrote: (1) If the result would drop below zero then throw an overflow error; (2) Use saturating subtraction, i.e. if the result would drop below zero then return zero; (3) Use type hackery to disallow performing subtraction when the result would drop b

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

On 3/17/11 2:50 PM, Luke Palmer wrote: If you are implementing lazy naturals, I wonder if defining 0 - 1 to be infinity makes mathematical sense. It's like arithmetic mod infinity Actually, I'm specifically implementing strict naturals :) There are a number of libraries for lazy naturals

Re: [Haskell-cafe] [Agda] Defining subtraction for naturals

If you are implementing lazy naturals, I wonder if defining 0 - 1 to be infinity makes mathematical sense. It's like arithmetic mod infinity Luke On Thu, Mar 17, 2011 at 12:35 PM, wren ng thornton wrote: > Another question on particulars. When dealing with natural numbers, we run > into the

[Haskell-cafe] Defining subtraction for naturals

Another question on particulars. When dealing with natural numbers, we run into the problem of defining subtraction. There are a few reasonable definitions: (1) If the result would drop below zero then throw an overflow error; (2) Use saturating subtraction, i.e. if the result would drop below

[Haskell-cafe] Haskell report minutiae

So I have a rules-lawyering question about how specified the overflow behavior is for the types Int and Word. * In the Haskell 2010 report it seems to be specified that (sections 18.1, 23.1): "All arithmetic is performed modulo 2^n, where n is the number of bits in the type." And this seems to

Re: [Haskell-cafe] tplot and splot - analyst's swiss army knifes for visualizing log files

Eugene Kirpichov writes: > 2010/12/17 Henning Thielemann : > >> Eugene Kirpichov schrieb: >> >>> I've published a large presentation about two Haskell-based tools of >>> mine - tplot and splot. >>> >>> Their motto is "visualize system behavior from logs with a shell one-liner". >>> Based on my ex

Re: [Haskell-cafe] Weird warnings from recent GHC snapshot

1) if you copy the 10.5sdk from developer-old into the new developer folder sdk folder, the standard ghc distro will work again 2) theres a ghc ticket for that, its apparently partly because theres no -nowarnunwind flag or the like On Thu, Mar 17, 2011 at 6:11 AM, Michael Vanier wrote: > I run h

[Haskell-cafe] wrong backquote in haskell 2010 report Prelude

Haskell 2010 report chapter 9 Standard Prelude uses a wrong backquote, e.g., infixl 7 ⋆, /, ‘quot‘, ‘rem‘, ‘div‘, ‘mod‘ Those are U+2018. The grammar (Chapter 3) requires U+0060 and accepts no substitutes, e.g., varop → varsym | ` varid ` ___ Ha

Re: [Haskell-cafe] Installation of Haskell Platform on CentOS 5.5

On Thu, Mar 17, 2011 at 07:52:01AM +0100, Ketil Malde wrote: > frode k writes: > > > Installation of GHC 7.0.2 failed: > > # ./configure --prefix=/usr/haskell-platform-2011.2.0.0/ > > checking for path to top of build tree... > > utils/ghc-pwd/dist/build/tmp/ghc-pwd: /lib64/libc.so.6: version `GLI

Re: [Haskell-cafe] How large is the Haskell community ?

> On Sat, Feb 12, 2011 at 6:57 PM, Jan Christiansen > wrote: > > On 12.02.2011, at 21:18, Aaron Gray wrote: > > I was wondering if anyone had an idea or estimate as to how large the > Haskell community is ? > > All the answers made me wonder what the criterion is to be a member o

Re: [Haskell-cafe] Lazy evaluation and tail-recursion

On Thursday 17 March 2011 13:05:33, Tillmann Rendel wrote: > Looks like I need an email client with ghc integration. That would be awesome. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] How large is the Haskell community ?

> http://steve-yegge.blogspot.com/2010/12/haskell-researchers-announce-discovery.html I love the sentence "We crafted a fake satirical post lampooning Haskell as an unusable, overly complex turd -- a writing task

Re: [Haskell-cafe] How large is the Haskell community ?

Clearly we need some sort of xbox live -like achievement system for these. Achievement Unlocked: Stumped Oleg! On Sat, Feb 12, 2011 at 6:57 PM, Jan Christiansen < j...@informatik.uni-kiel.de> wrote: > > On 12.02.2011, at 21:18, Aaron Gray wrote: > > I was wondering if anyone had an idea or esti

Re: [Haskell-cafe] Byte Histogram

Necroing this thread because I just noticed there's a (rather old!) bug report which covers much of the same ground and doesn't seem to have been mentioned by anyone: http://hackage.haskell.org/trac/ghc/ticket/1349 2011/2/8 Gábor Lehel : > 2011/2/8 Ketil Malde : >> Gábor Lehel writes: >> >>> Is

Re: [Haskell-cafe] Lazy evaluation and tail-recursion

Hi, Daniel Fischer wrote: Let's look at the following code: countdown n = if n == 0 then 0 else foo (n - 1) s/foo/countdown/ presumably if' c t e = if c then t else e countdown' n = if' (n == 0) 0 (foo (n - 1)) s/foo/countdown'/ Yes to both substitutions. Looks like I need

Re: [Haskell-cafe] Data.Time.Calendar.Day does not seem to have an instance for Read

> > > So then it's not a bug. The instance is defined in > Data.Time.Format.Parse, and Data.Time.Calendar doesn't import that > module. > > This, however is a bug, I think: > > Prelude> import Data.Time > Prelude Data.Time> read "2011-10-10" :: Day > > ... no instance for (Read Day) ... > > Prelude

[Haskell-cafe] Weird warnings from recent GHC snapshot

I run haskell on Mac OS X (Snow Leopard). After upgrading my Xcode installation to 4.0 I had a tricky time getting ghc working again; the version bundled with the Haskell Platform no longer works and I had to compile a recent snapshot (ghc-7.1.20110315) from source. This worked fine, but now

Re: [Haskell-cafe] Data.Time.Calendar.Day does not seem to have an instance for Read

On Thu, Mar 17, 2011 at 07:30, C K Kashyap wrote: >> On Thu, Mar 17, 2011 at 12:30 AM, C K Kashyap wrote: >> > Hi, >> > I was wondering if this is a defect - >> > Prelude> import Data.Time.Calendar >> > Prelude Data.Time.Calendar> read "2011-10-10" :: Day >> > :1:1: >> >     No instance for (Read