ST +Control.Monad +package
A monad transformer version of the ST monad Warning! This monad transformer should not be used with monads that can contain multiple answers, like the list monad. The reason is that the will be duplicated across the different answers and this cause Bad Things to happen (such as loss of referential transparency). Safe monads include the monads State, Reader, Writer, Maybe and combinations of their corresponding monad transformers.
Provides an unsafe API for inserting heterogeneous data in a collection keyed by StableNames and for later retrieving it.
Whereas most memo combinators memoize based on equality, stable-memo does it based on whether the exact same argument has been passed to the function before (that is, is the same argument in memory).
* stable-memo only evaluates keys to WHNF.
* This can be more suitable for recursive functions over graphs with cycles.
* stable-memo doesn't retain the keys it has seen so far, which allows them to be garbage collected if they will no longer be used. Finalizers are put in place to remove the corresponding entries from the memo table if this happens.
* Data.StableMemo.Weak provides an alternative set of combinators that also avoid retaining the results of the function, only reusing results if they have not yet been garbage collected.
* There is no type class constraint on the function's argument.
stable-memo will not work for arguments which happen to have the same value but are not the same heap object. This rules out many candidates for memoization, such as the most common example, the naive Fibonacci implementation whose domain is machine Ints; it can still be made to work for some domains, though, such as the lazy naturals.
> data Nat = Succ Nat | Zero
> fib :: Nat -> Integer
> fib = memo fib'
> where fib' Zero = 0
> fib' (Succ Zero) = 1
> fib' (Succ n1@(Succ n2)) = fib n1 + fib n2
Below is an implementation of map that preserves sharing of the spine for cyclic lists. It should even be safe to use this on arbitrarily long, acyclic lists since as long as the garbage collector is chasing you, the size of the memo table should stay under control, too.
> map :: (a -> b) -> [a] -> [b]
> map f = go
> where go = memo map'
> map'  = 
> map' (x:xs) = f x : go xs
This library is largely based on the implementation of memo found in "Stretching the storage manager: weak pointers and stable names in Haskell", from Simon Peyton Jones, Simon Marlow, and Conal Elliott (http://community.haskell.org/~simonmar/papers/weak.pdf).
Fundamental * -> * types, operators, and covariant instances.
Contravariant instances for the fundamental * -> * types and operators.
A haskell memcached client. See http://memcached.org for more information.
This implements the new binary protocol, so it only works with memcached version 1.3 and newer.
Space simulation game.
Implements MonadPlus with left catch (MonadOr) for StateT.
This package provides a Template Haskell function which transforms a normal record declaration into one which supports many useful operations when used as the state in a State monad.
A MonadST type class, instances, and some helpful monad functions.
A collection of type-classes generalizing the read/write/modify operations for stateful variables provided by things like IORef, TVar, &c. Note that The interface has changed a bit from the 0.2.* version. "*Ref" functions are now called "*Reference" and new "*Ref" function exist with simpler signatures. The new Ref existential type provides a convenient monad-indexed reference type, and the HasRef class indicates monads for which there is a default reference type for every referent.
Simple State-like monad transformer where states can be saved to and restored from an internal stack.
The ST monad and STRefs in a portable form. This package implements state threads as wrapper around IO and IORefs. Your compiler must support rank-2-types, IORefs, unsafePerformIO and unsafeInterleaveIO. The package can be used as drop-in replacement for the st package.
This package contains state variables, which are references in the IO monad, like IORefs or parts of the OpenGL state.
This is a version of the RWS monad transformers that should be much faster than what's found in transformers. The writer in the strict version does not leak memory.
Provides an interface to the cross platform system statistics C library libstatgrab.
It supports a wide range of system statistics including CPU usage, memory utilisation, disk usage, process counts, network traffic, disk I/O, and more.
The current list of supported and tested platforms for the underlying library includes OSX, FreeBSD, Linux, NetBSD, OpenBSD, Solaris, DragonFly BSD, HP-UX and AIX.
* libstatgrab 0.9.0 must be installed on the target system.
* Be aware that currently these bindings have been developed and tested only on OSX/Linux.
Haddock documentation can also be found on http://brendanhay.github.io/statgrab/System-Statgrab.html.
Pure immutable hash whose lookup is O(1)
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