diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,5 @@ +# Revision history for tokenizer-streaming + +## 0.1.0.0 -- YYYY-mm-dd + +* First version. Released on an unsuspecting world. diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,20 @@ +# tokenizer-streaming + +**Motivation**: You might have stumpled upon the package tokenizer-monad. It +is another project by me, for writing tokenizers that act on pure +text/strings. However, there are situations when you cannot keep all the text +in memory. You might want to tokenize text from network streams or from large +corpus files. + +**Main idea**: A monad transformer called `TokenizerT` implements exactly the +same methods as `Tokenizer` from tokenizer-monad, such that all tokenizers can +be ported without code changes (if you used `MonadTokenizer` in the type signatures) + +## Supported text types + + - streams of Char lists can be tokenized into streams of Char lists + - streams of strict Text can be tokenized into streams of strict Text + - streams of lazy Text can be tokenized into streams of lazy Text + - streams of strict ASCII ByteStrings can be tokenized into streams of strict ASCII ByteStrings + - streams of lazy ASCII ByteStrings can be tokenized into streams of lazy ASCII ByteStrings + - bytestring streams (from streaming-bytestring) with Unicode encodings (UTF-8, UTF-16 LE & BE, UTF-32 LE & BE) can be tokenized into streams of strict Text diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/src/Control/Monad/Tokenizer/Streaming.hs b/src/Control/Monad/Tokenizer/Streaming.hs new file mode 100644 --- /dev/null +++ b/src/Control/Monad/Tokenizer/Streaming.hs @@ -0,0 +1,198 @@ +{-# LANGUAGE FlexibleInstances #-} + +-- | A monad transformer for tokenizing streams of text. +-- +-- Main idea: You 'walk' through the input string like a turtle, and everytime +-- you find a token boundary, you call 'emit'. If some specific kinds of tokens +-- should be suppressed, you can 'discard' them instead (or filter afterwards). +-- +-- The package tokenizer-monad provides a monad (and class) for tokenizing +-- pure text/strings in memory. This package supplements it with a transformer +-- to work on impure Streams of text/strings. Your existing tokenizers can +-- be ported without code changes. +-- +-- This module supports strict text, lazy text, strings, lazy ASCII bytestrings and strict bytestrings. For working with Unicode encodings, have a look at "Control.Monad.Tokenizer.Streaming.Decode". +-- +-- For examples on how to write tokenizers, have a look at the package +-- tokenizer-monad. Here's an example on how to use it with streams: +-- +-- Example for a simple tokenizer, that splits words by whitespace and discards stop symbols: +-- +-- > tokenizeWords :: Monad m => Stream (Of T.Text) m () -> Stream (Of T.Text) m () +-- > tokenizeWords = runTokenizerT $ untilEOT $ do +-- > c <- pop +-- > if isStopSym c +-- > then discard +-- > else if c `elem` ("  \t\r\n" :: [Char]) +-- > then discard +-- > else do +-- > walkWhile (\c -> (c=='_') || not (isSpace c || isPunctuation' c)) +-- > emit + +module Control.Monad.Tokenizer.Streaming ( + -- * Monad transformer + TokenizerT, + runTokenizerT, + runTokenizerCST, + C.untilEOT, + -- * Tests + C.peek, + C.isEOT, + C.lookAhead, + -- * Movement + C.walk, + C.walkBack, + C.pop, + C.walkWhile, + C.walkFold, + -- * Transactions + C.emit, + C.discard, + C.restore, + -- * Text types + Tokenizable(..) + ) where + +import Control.Monad +import Control.Monad.Trans +import Data.Monoid +import qualified Streaming.Prelude as S +import Streaming +import qualified Control.Monad.Tokenizer.Class as C +import Control.Monad.Tokenizer.Char8.Lazy () +import Control.Monad.Tokenizer.Char8.Strict () +import qualified Data.Text as T +import qualified Data.Text.Lazy as LT +import qualified Data.ByteString.Char8 as BS +import qualified Data.ByteString.Lazy.Char8 as LBS + +-- | Tokenizer transformer. Use 'runTokenizerT' or 'runTokenizerCST' to run it +newtype TokenizerT t m a = TokenizerT { + runTokenizerT' :: (t,Stream (Of t) m ()) -> Stream (Of t) m (a,t,Stream (Of t) m ()) + } +-- (visited, remaining) -> Stream (of emissions) m (result, visited, remaining) + +-- | Split a text stream into tokens using the given tokenizer, case sensitive version +runTokenizerCST :: (Tokenizable t,Monad m) => TokenizerT t m a -> Stream (Of t) m () -> Stream (Of t) m a +runTokenizerCST tok ins = do + (a,_,_) <- runTokenizerT' tok (mempty,ins) + return a + +-- | Split a text stream into tokens using the given tokenizer +runTokenizerT :: (Tokenizable t,Monad m) => TokenizerT t m a -> Stream (Of t) m () -> Stream (Of t) m a +runTokenizerT tok = runTokenizerCST tok . S.map C.tlower + +-- | Text types that can be split by the TokenizerT transformer. In this module, +-- instances are provided for String, strict Text, and lazy Text. +-- There are also instances for strict and lazy ByteStrings, but keep in mind +-- that they assume ASCII encoding. If you want to apply reasonable decoding, +-- try Control.Monad.Tokenizer.Streaming.Decode. +class (C.Tokenizable t, Monoid t) => Tokenizable t where + tsingleton :: Char -> t + tinit :: t -> t + tlast :: t -> Char + +instance Tokenizable [Char] where + tsingleton = pure + tinit = init + tlast = last + +instance Tokenizable T.Text where + tsingleton = T.singleton + tinit = T.init + tlast = T.last + +instance Tokenizable LT.Text where + tsingleton = LT.singleton + tinit = LT.init + tlast = LT.last + +instance Tokenizable BS.ByteString where + tsingleton = BS.singleton + tinit = BS.init + tlast = BS.last + +instance Tokenizable LBS.ByteString where + tsingleton = LBS.singleton + tinit = LBS.init + tlast = LBS.last + +instance Monad m => Functor (TokenizerT t m) where + fmap = liftM + +instance Monad m => Applicative (TokenizerT t m) where + (<*>) = ap + pure = return + +instance Monad m => Monad (TokenizerT t m) where + return a = TokenizerT $ \(v,rem) -> return (a,v,rem) + m >>= f = TokenizerT $ \(v,rem) -> do + (a1,v1,rem1) <- runTokenizerT' m (v,rem) + (a2,v2,rem2) <- runTokenizerT' (f a1) (v1,rem1) + return (a2,v2,rem2) + +instance MonadTrans (TokenizerT t) where + lift m = TokenizerT $ \(v,rem) -> do + a <- lift m + return (a,v,rem) + +uncons1 :: (Monad m,Tokenizable t) => + Stream (Of t) m a -> m (Maybe (Char,Stream (Of t) m a)) +uncons1 stream = do + muc <- S.uncons stream + case muc of + Nothing -> return Nothing + Just (one,more) | C.tnull one -> uncons1 more + Just (one,more) -> + let (th, tt) = (C.thead one, C.ttail one) + more' | C.tnull tt = more + | otherwise = S.cons tt more + in return $ Just (th, more') + +unconsn :: (Monad m,Tokenizable t) => Int -> + Stream (Of t) m a -> m ([Char],Stream (Of t) m a) +unconsn 0 stream = return ([],stream) +unconsn n stream = do + muc <- uncons1 stream + case muc of + Nothing -> return ([],stream) + Just (h,stream') -> do + (t,stream'') <- unconsn (n-1) stream' + return (h:t,stream'') + +instance (Monad m, Tokenizable t) => C.MonadTokenizer (TokenizerT t m) where + walk = void C.pop + pop = TokenizerT $ \(v,rem) -> do + muc <- lift $ uncons1 rem + case muc of + Nothing -> return ('\0',v,rem) + Just (h,rem') -> return (h,v<>tsingleton h,rem') + peek = TokenizerT $ \(v,rem) -> do + muc <- lift $ uncons1 rem + case muc of + Nothing -> return ('\0',v,rem) + Just (h,_) -> return (h,v,rem) + restore = TokenizerT $ \(v,rem) -> return ((),mempty,S.cons v rem) + emit = TokenizerT $ \(v,rem) -> S.yield v >> return ((),mempty,rem) + discard = TokenizerT $ \(v,rem) -> return ((),mempty,rem) + isEOT = TokenizerT $ \(v,rem) -> do + muc <- lift $ S.uncons rem + case muc of + Nothing -> return (True,v,rem) + Just _ -> return (False,v,rem) + lookAhead cs = TokenizerT $ \(v,rem) -> do + (cs',_) <- lift $ unconsn (length cs) rem + return (cs == cs', v, rem) + walkBack = TokenizerT $ \(v,rem) -> + if C.tnull v + then return ((),v,rem) + else return ((),tinit v,S.cons (tsingleton $ tlast v) rem) + +words' :: C.MonadTokenizer m => m () +words' = C.untilEOT $ do + c <- C.pop + if c `elem` " \t\n\r" + then C.discard + else do + C.walkWhile (\c -> not (c `elem` " \t\n\r")) + C.emit diff --git a/src/Control/Monad/Tokenizer/Streaming/Decode.hs b/src/Control/Monad/Tokenizer/Streaming/Decode.hs new file mode 100644 --- /dev/null +++ b/src/Control/Monad/Tokenizer/Streaming/Decode.hs @@ -0,0 +1,101 @@ +-- | Functions for running 'M.TokenizerT' on Unicode bytestring streams. +-- +-- For more information on how to work with 'M.TokenizerT', have a look at the +-- module "Control.Monad.Tokenizer.Streaming". For more information on writing +-- tokenizers, have a look at the module "Control.Monad.Tokenizer" from the +-- package tokenizer-monad. +-- +-- Example for a simple tokenizer, that splits words by whitespace and discards stop symbols: +-- +-- > tokenizeWords :: Monad m => Q.ByteString m () -> Stream (Of T.Text) m () +-- > tokenizeWords = runUtf8TokenizerT $ untilEOT $ do +-- > c <- pop +-- > if isStopSym c +-- > then discard +-- > else if c `elem` ("  \t\r\n" :: [Char]) +-- > then discard +-- > else do +-- > walkWhile (\c -> (c=='_') || not (isSpace c || isPunctuation' c)) +-- > emit + +module Control.Monad.Tokenizer.Streaming.Decode ( + -- * UTF-8 + runUtf8TokenizerT, + runUtf8TokenizerCST, + -- * UTF-16 + runUtf16LETokenizerT, + runUtf16LETokenizerCST, + runUtf16BETokenizerT, + runUtf16BETokenizerCST, + -- * UTF-32 + runUtf32LETokenizerT, + runUtf32LETokenizerCST, + runUtf32BETokenizerT, + runUtf32BETokenizerCST, + -- * Helpers + module Control.Monad.Tokenizer.Streaming, + runDecodingTokenizerT, + runDecodingTokenizerCST, + decodeStream + ) where + +import qualified Control.Monad.Tokenizer.Streaming as M +import qualified Control.Monad.Tokenizer.Streaming +import Streaming +import qualified Streaming.Prelude as S +import qualified Data.Text as T +import qualified Data.ByteString.Streaming as Q +import qualified Data.ByteString as BS +import Data.Streaming.Text + +-- | Decode a Unicode bytestring stream into a stream of Text chunks. +decodeStream :: Monad m => (BS.ByteString -> DecodeResult) -> Q.ByteString m () -> Stream (Of T.Text) m () +decodeStream decoder = + let step decode stream = do + muc <- lift $ S.uncons stream + case muc of + Nothing -> + case decoder BS.empty of + DecodeResultFailure succ _ -> do + S.yield succ + fail "Decoding ended ungracefully" + DecodeResultSuccess succ _ -> do + S.yield succ + Just (one,more) | BS.null one -> step decode more + | otherwise -> + case decoder one of + DecodeResultFailure succ _ -> do + S.yield succ + fail "Decoding error" + DecodeResultSuccess succ cont -> do + S.yield succ + step cont more + in step decoder . Q.toChunks + +runDecodingTokenizerCST :: Monad m => (BS.ByteString -> DecodeResult) -> M.TokenizerT T.Text m a -> Q.ByteString m () -> Stream (Of T.Text) m a +runDecodingTokenizerCST decoder tok ins = + M.runTokenizerCST tok $ decodeStream decoder ins + +runDecodingTokenizerT :: Monad m => (BS.ByteString -> DecodeResult) -> M.TokenizerT T.Text m a -> Q.ByteString m () -> Stream (Of T.Text) m a +runDecodingTokenizerT decoder tok ins = + M.runTokenizerT tok $ decodeStream decoder ins + +runUtf8TokenizerCST, runUtf8TokenizerT, runUtf16LETokenizerCST, + runUtf16LETokenizerT, runUtf16BETokenizerCST, runUtf16BETokenizerT, + runUtf32LETokenizerCST, runUtf32LETokenizerT, runUtf32BETokenizerCST, + runUtf32BETokenizerT :: Monad m => M.TokenizerT T.Text m a -> Q.ByteString m () -> Stream (Of T.Text) m a + +runUtf8TokenizerCST = runDecodingTokenizerCST decodeUtf8 +runUtf8TokenizerT = runDecodingTokenizerT decodeUtf8 + +runUtf16LETokenizerCST = runDecodingTokenizerCST decodeUtf16LE +runUtf16LETokenizerT = runDecodingTokenizerT decodeUtf16LE + +runUtf16BETokenizerCST = runDecodingTokenizerCST decodeUtf16BE +runUtf16BETokenizerT = runDecodingTokenizerT decodeUtf16BE + +runUtf32LETokenizerCST = runDecodingTokenizerCST decodeUtf32LE +runUtf32LETokenizerT = runDecodingTokenizerT decodeUtf32LE + +runUtf32BETokenizerCST = runDecodingTokenizerCST decodeUtf32BE +runUtf32BETokenizerT = runDecodingTokenizerT decodeUtf32BE diff --git a/tokenizer-streaming.cabal b/tokenizer-streaming.cabal new file mode 100644 --- /dev/null +++ b/tokenizer-streaming.cabal @@ -0,0 +1,83 @@ +cabal-version: 2.0 + +-- Initial package description 'tokenizer-streaming.cabal' generated by +-- 'cabal init'. For further documentation, see +-- http://haskell.org/cabal/users-guide/ + +-- The name of the package. +name: tokenizer-streaming + +-- The package version. See the Haskell package versioning policy (PVP) +-- for standards guiding when and how versions should be incremented. +-- https://pvp.haskell.org +-- 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 variant of tokenizer-monad that supports streaming. + +-- A longer description of the package. +description: This monad transformer is a modification of tokenizer-monad + that can work on streams of text/string chunks or even on + (Unicode) bytestring streams. Thus + +-- A URL where users can report bugs. +-- bug-reports: + +-- The license under which the package is released. +license: GPL-3 + +-- The file containing the license text. +license-file: LICENSE + +-- The package author(s). +author: Enum Cohrs + +-- An email address to which users can send suggestions, bug reports, and +-- patches. +maintainer: darcs@enumeration.eu + +-- A copyright notice. +copyright: (c) 2019 Enum Cohrs + +category: Text + +build-type: Simple + +-- Extra files to be distributed with the package, such as examples or a +-- README. +extra-source-files: CHANGELOG.md + README.md + +source-repository head + type: darcs + location: https://hub.darcs.net/enum/tokenizer-streaming + +library + -- Modules exported by the library. + exposed-modules: Control.Monad.Tokenizer.Streaming + Control.Monad.Tokenizer.Streaming.Decode + + -- 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 ^>=4.9.1.0, + streaming, + tokenizer-monad ^>= 0.2.2.0, + text, + bytestring, + mtl, + streaming-commons ^>= 0.2.1.0, + streaming-bytestring >= 0.1.6 + + -- Directories containing source files. + hs-source-dirs: src + + -- Base language which the package is written in. + default-language: Haskell2010