acme-strtok (empty) → 0.1.0.0

raw patch · 4 files changed

+198/−0 lines, 4 filesdep +basedep +mtlsetup-changed

Dependencies added: base, mtl

Files

• Acme/StrTok.hs +105/−0
• LICENSE +24/−0
• Setup.hs +2/−0
• acme-strtok.cabal +67/−0

@@ -0,0 +1,105 @@+{-|+Module      : StrTok+Description : Provides the strTok function+License     : Public Domain+Maintainer  : Manuel Eberl <last name + m _at_ in.tum.de>+Stability   : experimental++This module provides the function @strTok@, a variant of the @strtok@ function in C and PHP. This function can be +used to tokenise a string (or, more generally, a list) with successive calls of the @strtok@ function. Since +@strTok@ is a stateful function (it produces different results when called with the same parameter multiple times), +computations using @strTok@ must take place in the @StrTok@ monad or the @StrTokT@ monad transformer.+-}+module Acme.StrTok (+    -- * The StrTokT monad transformer+    StrTokT,+    runStrTokT,+    -- * The StrTok monad+    StrTok,+    runStrTok,+    -- * The strTok function+    strTok+  ) where++import Control.Applicative+import Control.Monad+import Control.Monad.Identity+import Control.Arrow+import Control.Monad.Trans+++-- | The @StrTokT@ monad, parametrised with:+--+--   * @s@ - The type of list elements (e.g. @Char@ if the input to @strTok@ is a @String@).+--+--   * @m@ - The inner monad.+newtype StrTokT s m a = StrTokT { runStrTokT' :: [s] -> m (a, [s]) }++instance Functor m => Functor (StrTokT s m) where+  fmap f (StrTokT g) = StrTokT $ fmap (first f) . g+  +instance (Functor m, Monad m) => Applicative (StrTokT s m) where+  pure  = return+  (<*>) = ap+  +instance (Functor m, MonadPlus m) => Alternative (StrTokT s m) where+  empty = mzero+  (<|>) = mplus+    +instance (MonadPlus m) => MonadPlus (StrTokT s m) where+  mzero       = StrTokT $ const mzero+  m `mplus` n = StrTokT $ \s -> runStrTokT' m s `mplus` runStrTokT' n s++instance (MonadFix m) => MonadFix (StrTokT s m) where+  mfix f = StrTokT $ \s -> mfix $ \ ~(a, _) -> runStrTokT' (f a) s   ++instance Monad m => Monad (StrTokT s m) where+  return x = StrTokT $ \s -> return (x,s)+  StrTokT f >>= g = StrTokT $ \s -> do {(x,s) <- f s; runStrTokT' (g x) s}++instance MonadTrans (StrTokT s) where+  lift m = StrTokT $ \s -> do {x <- m; return (x,s)}+  +instance (MonadIO m) => MonadIO (StrTokT s m) where+    liftIO = lift . liftIO++-- | Executes a @strTok@ computation in the state transformer monad @StrTokT@.+runStrTokT :: Functor m => StrTokT s m a -> m a+runStrTokT (StrTokT f) = fmap fst (f [])++++-- | The @StrTok@ monad.+type StrTok s = StrTokT s Identity++-- | Executes a @strTok@ computation in the state monad @StrTok@.+runStrTok :: StrTok s a -> a+runStrTok = runIdentity . runStrTokT++++-- | A Haskell variant of the @strtok@ function from C and PHP. This function splits a string into tokens which are+-- delimited by a given set of characters. A call with @Just s@ and the delimiting characters @ds@ will yield +-- the first token in @s@ that is delimited by characters from @ds@. Every subsequent call of @strTok@ with @Nothing@ +-- will yield the next token. If the string contains no more tokens, an empty list is returned.+--+-- @strTok@ returns a stateful computation of type @StrTokT a m [a]@ (or @StrTok a [a]@). +-- Several invocations of @strTok@ and computations with the results can be chained in the @StrTokT@ (resp. @StrTok@) +-- monad and then executed with @runStrTokT@ (resp. @runStrTok@).+-- +-- Example:+--+-- >runStrTokT $+-- >      do a <- strTok (Just "- This, a sample string.") " ,.-"+-- >         b <- strTok Nothing " ,.-"+-- >         c <- strTok Nothing ",.-"+-- >         return (a, b, c)+--+-- evaluates to+--+-- >("This","a"," sample string")+strTok :: (Eq a, Monad m) => Maybe [a] -> [a] -> StrTokT a m [a]+strTok s delims = StrTokT $ maybe strTok' (const . strTok') s+  where strTok' = return . break (`elem` delims) . dropWhile (`elem` delims)++

@@ -0,0 +1,24 @@+This is free and unencumbered software released into the public domain.++Anyone is free to copy, modify, publish, use, compile, sell, or+distribute this software, either in source code form or as a compiled+binary, for any purpose, commercial or non-commercial, and by any+means.++In jurisdictions that recognize copyright laws, the author or authors+of this software dedicate any and all copyright interest in the+software to the public domain. We make this dedication for the benefit+of the public at large and to the detriment of our heirs and+successors. We intend this dedication to be an overt act of+relinquishment in perpetuity of all present and future rights to this+software under copyright law.++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR+OTHER DEALINGS IN THE SOFTWARE.++For more information, please refer to <http://unlicense.org/>

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

@@ -0,0 +1,67 @@+-- Initial acme-strtok.cabal generated by cabal init.  For further +-- documentation, see http://haskell.org/cabal/users-guide/++-- The name of the package.+name:                acme-strtok++-- The package version.  See the Haskell package versioning policy (PVP) +-- for standards guiding when and how versions should be incremented.+-- http://www.haskell.org/haskellwiki/Package_versioning_policy+-- PVP summary:      +-+------- breaking API changes+--                   | | +----- non-breaking API additions+--                   | | | +--- code changes with no API change+version:             0.1.0.0++-- A short (one-line) description of the package.+synopsis:            A Haskell port of the C/PHP strtok function++-- A longer description of the package.+-- description:      This package provides a Haskell version of the strtok function from C/PHP. Successive calls of this function return tokens (delimited by given delimiting characters) from a string (or a list), one by one.++-- The license under which the package is released.+license:             PublicDomain++-- The file containing the license text.+license-file:        LICENSE++-- The package author(s).+author:              Manuel Eberl++-- An email address to which users can send suggestions, bug reports, and +-- patches.+maintainer:          last name + m _at_ in.tum.de++-- A copyright notice.+-- copyright:           ++category:            ACME++build-type:          Simple++-- Extra files to be distributed with the package, such as examples or a +-- README.+-- extra-source-files:  ++-- Constraint on the version of Cabal needed to build this package.+cabal-version:       >=1.10+++library+  -- Modules exported by the library.+  exposed-modules:     Acme.StrTok+  +  -- Modules included in this library but not exported.+  -- other-modules:       +  +  -- LANGUAGE extensions used by modules in this package.+  -- other-extensions:    +  +  -- Other library packages from which modules are imported.+  build-depends:       base >=4.6 && <4.7, mtl >=2.1 && <2.2+  +  -- Directories containing source files.+  -- hs-source-dirs:      +  +  -- Base language which the package is written in.+  default-language:    Haskell2010+