[Haskell-cafe] Using Haskell's FFI to send ancillary data over Unix domain sockets

Unix domain sockets are a type of socket created between two programs on a single Unix system. They are useful in part because over them you can send so-called ancillary data: file descriptors and credentials (i.e. a proof of who the process on the other end is). The thing is, Haskell doesn't have

Re: [Haskell-cafe] List operation question

On 2/4/07, Eric Olander <[EMAIL PROTECTED]> wrote: Hi, I'm still somewhat new to Haskell, so I'm wondering if there are better ways I could implement the following functions, especially shiftl: >> moves the last element to the head of the list shiftl :: [a] -> [a] shiftl [] = [] s

Re: [Haskell-cafe] rebinding >>= for restricted monads

On 12/17/06, David Roundy <[EMAIL PROTECTED]> wrote: Hello fellow haskellers, I am wondering if anyone has an idea whether I'd run into trouble if I rebound >>= in order to provide a more restricted monad. My idea is to define a class: . . . which seems rather heavy. Can anyone think of sy

Re: Re: [Haskell-cafe] beginner's problem about lists

On 10/10/06, Nicolas Frisby <[EMAIL PROTECTED]> wrote: > data Fin > data Inf > data List l a = Cons a (List l a) | Nil It's possible to make both "infinite list" and "finite list" datatypes: data Inf a = InfCons a (Inf a) data Fin a = FinCons a !(Fin a) | FinNil At least, I think the Fin typ

Re: [Haskell-cafe] Haskell performance (again)!

On 10/8/06, ihope <[EMAIL PROTECTED]> wrote: Keep the internals of your code--that which will be looked at a lot--fast and ugly, while the rest can be clean. Sorry. Meant "that which will be used a lot". ___ Haskell-Cafe mailing l

Re: [Haskell-cafe] Haskell performance (again)!

On 10/8/06, Yang <[EMAIL PROTECTED]> wrote: And do most (experienced) Haskell users sacrifice cleanliness for speed, or speed for cleanliness? Keep the internals of your code--that which will be looked at a lot--fast and ugly, while the rest can be clean. If you have a function that does someth

Re: [Haskell-cafe] Defining show for a function type.

On 7/10/06, Fritz Ruehr <[EMAIL PROTECTED]> wrote: Were you interested in "seeing" the function, you could do so, at least for finite, total functions (you can also enumerate them, compare them for equality, etc.). See my haskell-cafe message at

Re: [Haskell-cafe] help with creating a DAG?

On 7/8/06, David Roundy <[EMAIL PROTECTED]> wrote: Hi all, I'm wanting to create a data structure to hold a directed acyclic graph (which will have patches represented by edges), and haven't yet been able to figure out a nice representation. I'd like one that can be reasoned with recursively, o

Re: [Haskell-cafe] Re: Strictness in do block

On 7/5/06, John Goerzen <[EMAIL PROTECTED]> wrote: On 2006-07-05, Duncan Coutts <[EMAIL PROTECTED]> wrote: > evaluate is for just that purpose. > > evaluate (length input) > > > from the docs: > > http://haskell.org/ghc/docs/latest/html/libraries/base/Control-Exception.html#v%3Aevaluate That lo

Re: [Haskell-cafe] A question about stack overflow

es the stack overflow, though for a different reason. How about this: maximum (a:b:xs) = maximum ((: xs) $! max a b) --ihope ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] Haskell + Windows API = wuh?

here do I start? --ihope ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] Spawning a terminal window?

Does Haskell have a handy way to spawn a new terminal window and give you a handle to access it with? --ihope ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] The case of the missing module

In the Haddock source, there's the following line: import Paths_haddock( getDataDir ) Paths_haddock doesn't seem to be anywhere inside the Haddock distribution, and a Google search doesn't turn up any useful results. Where can I find this thing? ___

Re: [Haskell-cafe] #if and #endif

On 4/13/06, Jason Dagit <[EMAIL PROTECTED]> wrote: > Try using passing -cpp to ghc when you compile. > > Jason Thanks. Will do. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] #if and #endif

I grabbed the source code to Haddock, but GHC doesn't like the #if's and the #endif's. What can I do with these? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Ambiguous types for collection keys

On 4/12/06, Scott Weeks <[EMAIL PROTECTED]> wrote: > Hello everyone, > > I've been banging my head against my desk a bit so I figured it's time > to ask for help :-) > > When a user queries I have to read the input from IO and then somehow > cast the key/index type without angering the type checker

Re: [Haskell-cafe] Re: Justification for Ord inheriting from Eq?

On 4/7/06, Jared Updike <[EMAIL PROTECTED]> wrote: > > given an Ord instance (for a type T) a corresponding Eq instance can be > > given by: > > > > instance Eq T where > > a == b = compare a b == EQ > > where did this second -^ == come from? (I guess if if Ordering > derives Eq :-) I think

Re: [Haskell-cafe] Re: [Haskell] What's up with this Haskell runtime error message:

On 4/5/06, Michael Goodrich <[EMAIL PROTECTED]> wrote: > Looks like my calulation involves a self referential set of definitions. > > Is Haskell not able to deal with a self referential set of definitions? Yes, it is, but not if that definition doesn't evaluate to a "proper" value. For example:

Re: [Haskell-cafe] Re: Positive integers

On 3/29/06, Aaron Denney <[EMAIL PROTECTED]> wrote: > (And yes, we desperately need something like class aliases.) You mean like this? class Foo a b where foo :: a -> b class Foo a b => Bar a b where instance Foo a b => Bar a b where This will make every instance of Foo one of Bar, and make

Re: [Haskell-cafe] Re: Equirecursive types?

On 3/27/06, lee marks <[EMAIL PROTECTED]> wrote: > So this is legal: > > type Fix s a = s a (Fix s a) > > fold :: Functor (s a) => (s a b -> b) -> Fix s a -> b > fold f = f . fmap (fold f) > > but this is not: > > fold f = f . fmap (fold f) data Fix s a = Fix {runFix :: s a (Fix s a)} fol

Re: [Haskell-cafe] Re: Positive integers

On 3/24/06, Henning Thielemann <[EMAIL PROTECTED]> wrote: > A new type, say Cardinal as in Modula, would document for the user of a > function that only non-negative numbers are allowed and the function > writer can be sure, that only non-negative numbers are passed. > > ... > > newtype Cardinal

[Haskell-cafe] A syntax proposal: data replacements

I'd like to propose more syntactic sugar more Haskell. (A spoonful of syntactic sugar makes the medicine go down...) Put simply, this would provide a smallish bit of pattern matching, and hopefully clarify some things. A simple example should pretty much define the whole thing: fromJust = {Just -

[Haskell-cafe] My piece of an IRC bot

Today I started on a simple IRC bot framework thingy. I decided to post the source code here so people can look at it and tell me what the heck I did wrong :-P > module IRC where > > import Control.Monad.State > import System.IO > import Network > > {--}{---