html-charset (empty) → 0.1.0
raw patch · 9 files changed
+900/−0 lines, 9 filesdep +QuickCheckdep +attoparsecdep +basesetup-changed
Dependencies added: QuickCheck, attoparsec, base, bytestring, charsetdetect-ae, doctest, doctest-discover, hlint, html-charset, optparse-applicative
Files
- CHANGES.md +7/−0
- LICENSE +502/−0
- README.md +69/−0
- Setup.hs +2/−0
- app/Main.hs +39/−0
- html-charset.cabal +84/−0
- src/Text/Html/Encoding/Detection.hs +184/−0
- test/doctest.hs +1/−0
- test/hlint.hs +12/−0
+ CHANGES.md view
@@ -0,0 +1,7 @@+html-charset changelog+======================++Version 0.1.0+-------------++Initial release. Released on July 11, 2018.
+ LICENSE view
@@ -0,0 +1,502 @@+ GNU LESSER GENERAL PUBLIC LICENSE+ Version 2.1, February 1999++ Copyright (C) 1991, 1999 Free Software Foundation, Inc.+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.++[This is the first released version of the Lesser GPL. It also counts+ as the successor of the GNU Library Public License, version 2, hence+ the version number 2.1.]++ Preamble++ The licenses for most software are designed to take away your+freedom to share and change it. By contrast, the GNU General Public+Licenses are intended to guarantee your freedom to share and change+free software--to make sure the software is free for all its users.++ This license, the Lesser General Public License, applies to some+specially designated software packages--typically libraries--of the+Free Software Foundation and other authors who decide to use it. 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+ README.md view
@@ -0,0 +1,69 @@+html-charset: Determine character encoding of HTML bytes+========================================================++[][html-charset]++This provides a [Haskell library][html-charset] and a CLI executable to+determine character encoding (i.e., so-called "charset") from given HTML bytes.++The precendence order for determining the character encoding is:++ 1. A BOM (byte order mark) before any other data in the HTML document itself.+ 2. A `<meta>` declaration with a `charset` attribute or an `http-equiv`+ attribute set to `Content-Type` and a value set for `charset`.+ Note that it looks at only first 1024 bytes.+ 3. [Mozilla's Charset Detectors][chardet] heuristics. To be specific,+ it delegates to the [charsetdetect-ae] package, a Haskell implementation+ of that.++[html-charset]: https://hackage.haskell.org/package/html-charset+[chardet]: https://www-archive.mozilla.org/projects/intl/chardet.html+[charsetdetect-ae]: https://hackage.haskell.org/package/charsetdetect-ae+++API+---++The package is available on Hackage: *[html-charset]*.++~~~~ haskell+>>> import Data.ByteString.Lazy+>>> import Text.Html.Encoding.Detection+>>> detect "\xef\xbb\xbf\xe4\xbd\xa0\xe5\xa5\xbd<html><head>..."+Just "UTF-8"+>>> detect "<html><head><meta charset=latin-1>..."+Just "latin-1"+>>> detect "<html><head><title>\xbe\xee\xbc\xad\xbf\xc0\xbc\xbc\xbf\xe4..."+Just "EUC-KR"+~~~~++Note that the `detect` function takes a lazy bytestring, not strict.++Read the [API docs] for details.+++CLI+---++We currently doesn't provide any official binaries.+The CLI program can be installed using Cabal or Stack: *[html-charset]*.++~~~~+$ curl https://www.haskell.org/onlinereport/ | html-charset+ASCII+$ curl http://www.bunka.go.jp/kokugo_nihongo/sisaku/joho/joho/ | html-charset+shift_jis+~~~~++Although it's less likely, `html-charset` may fail to determine the character+encoding, and for the case it prints nothing (only a line feed, exactly).+You can customize the string to print when it fails by configuring+`-f`/`--on-failure` option.++Author and license+------------------++Witten by [Hong Minhee]. Licensed under [LGPL 2.1] or higher.++[Hong Minhee]: https://hongminhee.org/+[LGPL 2.1]: https://www.gnu.org/licenses/lgpl-2.1.html
+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ app/Main.hs view
@@ -0,0 +1,39 @@+module Main where++import Data.Semigroup ((<>))++import qualified Data.ByteString.Lazy+import Options.Applicative++import Text.Html.Encoding.Detection++newtype Detector = Detector+ { onFailure :: String+ }++runDetector :: Detector -> IO ()+runDetector Detector { onFailure = onFailure' } = do+ html <- Data.ByteString.Lazy.getContents+ case detect html of+ Just encoding -> putStrLn encoding+ Nothing -> putStrLn onFailure'++detector :: Parser Detector+detector = Detector+ <$> strOption+ ( long "on-failure"+ <> short 'f'+ <> help "String to print when it fails to detect the character encoding"+ <> showDefault+ <> value ""+ )++detectorOpts :: ParserInfo Detector+detectorOpts = info (detector <**> helper)+ ( fullDesc+ <> progDesc "Detect character encoding of HTML documents/fragments"+ )++main :: IO ()+main =+ runDetector =<< execParser detectorOpts
+ html-charset.cabal view
@@ -0,0 +1,84 @@+-- This file has been generated from package.yaml by hpack version 0.20.0.+--+-- see: https://github.com/sol/hpack+--+-- hash: 099e0dc8959de54391d803d7ecc8f5294b7b59d0936610a8c30921c3758bb3b1++name: html-charset+version: 0.1.0+synopsis: Determine character encoding of HTML documents/fragments+description: Please see the README.md on GitHub at <https://github.com/dahlia/html-charset#readme>.+category: Web+homepage: https://github.com/dahlia/html-charset#readme+bug-reports: https://github.com/dahlia/html-charset/issues+author: Hong Minhee <hong.minhee@gmail.com>+maintainer: Hong Minhee <hong.minhee@gmail.com>+copyright: (c) 2018 Hong Minhee+license: LGPL-2.1+license-file: LICENSE+build-type: Simple+cabal-version: >= 1.10++extra-source-files:+ CHANGES.md+ README.md++source-repository head+ type: git+ location: https://github.com/dahlia/html-charset++library+ hs-source-dirs:+ src+ ghc-options: -Wall -fwarn-incomplete-uni-patterns -fprint-explicit-kinds+ build-depends:+ attoparsec >=0.12 && <1+ , base >=4.7 && <5+ , bytestring+ , charsetdetect-ae >=1.1 && <2+ exposed-modules:+ Text.Html.Encoding.Detection+ other-modules:+ Paths_html_charset+ default-language: Haskell2010++executable html-charset+ main-is: Main.hs+ hs-source-dirs:+ app+ ghc-options: -Wall -fwarn-incomplete-uni-patterns -fprint-explicit-kinds -threaded -rtsopts -with-rtsopts=-N+ build-depends:+ base >=4.7 && <5+ , bytestring+ , html-charset+ , optparse-applicative >=0.14 && <1+ other-modules:+ Paths_html_charset+ default-language: Haskell2010++test-suite doctest+ type: exitcode-stdio-1.0+ main-is: doctest.hs+ hs-source-dirs:+ test+ ghc-options: -Wall -fwarn-incomplete-uni-patterns -fprint-explicit-kinds -threaded+ build-depends:+ QuickCheck+ , base >=4.7 && <5+ , bytestring+ , doctest+ , doctest-discover+ , html-charset+ default-language: Haskell2010++test-suite hlint+ type: exitcode-stdio-1.0+ main-is: hlint.hs+ hs-source-dirs:+ test+ ghc-options: -Wall -fwarn-incomplete-uni-patterns -fprint-explicit-kinds -threaded+ build-depends:+ base >=4.7 && <5+ , bytestring+ , hlint >=2.1.7 && <2.2+ default-language: Haskell2010
+ src/Text/Html/Encoding/Detection.hs view
@@ -0,0 +1,184 @@+{-# LANGUAGE OverloadedStrings #-}+module Text.Html.Encoding.Detection+ ( EncodingName+ , detect+ , detectBom+ , detectMetaCharset+ ) where++import Control.Monad+import Data.Maybe+import Data.Word+import Prelude hiding (drop, take)++import Data.Attoparsec.ByteString hiding (Done, Fail, Result, parse, take)+import Data.Attoparsec.ByteString.Lazy (Result (..), parse)+import Codec.Text.Detect (detectEncodingName)+import qualified Data.ByteString+import Data.ByteString.Lazy++-- | Represent a name of text encoding (i.e., @charset@). E.g., @"UTF-8"@.+type EncodingName = String++-- | Detect the character encoding from a given HTML fragment. The precendence+-- order for determining the character encoding is:+--+-- 1. A BOM (byte order mark) before any other data in the HTML document itself.+-- (See also 'detectBom' function for details.)+-- 2. A @<meta>@ declaration with a @charset@ attribute or an @http-equiv@+-- attribute set to @Content-Type@ and a value set for @charset@.+-- Note that it looks at only first 1024 bytes.+-- (See also 'detectMetaCharset' for details.)+-- 3. [Mozilla's Charset+-- Detectors](https://www-archive.mozilla.org/projects/intl/chardet.html)+-- heuristics. To be specific, it delegates to 'detectEncodingName' from the+-- [charsetdetect-ae](https://hackage.haskell.org/package/charsetdetect-ae)+-- package, a Haskell implementation of that.+--+-- >>> :set -XOverloadedStrings+-- >>> detect "\xef\xbb\xbf\xe4\xbd\xa0\xe5\xa5\xbd<html><head>..."+-- Just "UTF-8"+-- >>> detect "<html><head><meta charset=latin-1>..."+-- Just "latin-1"+-- >>> detect "<html><head><title>\xbe\xee\xbc\xad\xbf\xc0\xbc\xbc\xbf\xe4..."+-- Just "EUC-KR"+--+-- It may return 'Nothing' if it fails to determine the character encoding,+-- although it's less likely.+detect :: ByteString -> Maybe EncodingName+detect fragment =+ listToMaybe $ mapMaybe ($ fragment)+ [ detectBom+ , detectMetaCharset . take 1024+ , detectEncodingName+ ]++-- | Detect the character encoding from a given HTML fragment by looking the+-- initial BOM (byte order mark).+--+-- >>> :set -XOverloadedStrings+-- >>> detectBom "\xef\xbb\xbf\xe4\xbd\xa0\xe5\xa5\xbd"+-- Just "UTF-8"+-- >>> detectBom "\xfe\xff\x4f\x60\x59\x7d"+-- Just "UTF-16BE"+-- >>> detectBom "\xff\xfe\x60\x4f\x7d\x59"+-- Just "UTF-16LE"+-- >>> detectBom "\x00\x00\xfe\xff\x00\x00\x4f\x60\x00\x00\x59\x7d"+-- Just "UTF-32BE"+-- >>> detectBom "\xff\xfe\x00\x00\x60\x4f\x00\x00\x7d\x59\x00\x00"+-- Just "UTF-32LE"+-- >>> detectBom "\x84\x31\x95\x33\xc4\xe3\xba\xc3"+-- Just "GB-18030"+--+-- It returns 'Nothing' if it fails to find no valid BOM sequence.+--+-- >>> detectBom "foobar"+-- Nothing+detectBom :: ByteString -> Maybe EncodingName+detectBom fragment =+ case take 2 fragment of+ "\xfe\xff" -> Just "UTF-16BE"+ "\xef\xbb" -> if take 1 (drop 2 fragment) == "\xbf"+ then Just "UTF-8"+ else Nothing+ "\x00\x00" -> if take 2 (drop 2 fragment) == "\xfe\xff"+ then Just "UTF-32BE"+ else Nothing+ "\xff\xfe" -> if take 2 (drop 2 fragment) == "\x00\x00"+ then Just "UTF-32LE"+ else Just "UTF-16LE"+ "\x84\x31" -> if take 2 (drop 2 fragment) == "\x95\x33"+ then Just "GB-18030"+ else Nothing+ _ -> Nothing++-- | Detect the character encoding from a given HTML fragment by looking+-- a @<meta>@ declaration with a @charset@ attribute or an @http-equiv@+-- attribute set to @Content-Type@ and a value set for @charset@.+--+-- >>> :set -XOverloadedStrings+-- >>> detectMetaCharset "<html><head><meta charset=utf-8>"+-- Just "utf-8"+-- >>> detectMetaCharset "<html><head><meta charset='EUC-KR'>"+-- Just "EUC-KR"+-- >>> detectMetaCharset "<html><head><meta charset=\"latin-1\"/></head></html>"+-- Just "latin-1"+-- >>> :{+-- detectMetaCharset+-- "<meta http-equiv=content-type content='text/html; charset=utf-8'>"+-- :}+-- Just "utf-8"+--+-- Return 'Nothing' if it failed to any appropriate @<meta>@ tag:+--+-- >>> detectMetaCharset "<html><body></body></html>"+-- Nothing+detectMetaCharset :: ByteString -> Maybe EncodingName+detectMetaCharset fragment =+ case parse html fragment of+ Fail {} -> Nothing+ Done _ r -> decodeAscii <$> r+ where+ html :: Parser (Maybe Data.ByteString.ByteString)+ html = do+ metas <- many' $ choice+ [ do+ -- [^<]++ void $ takeWhile1 (/= 0x3c)+ return Nothing+ , metaCharset+ , do+ -- [<]+ void $ word8 0x3c+ return Nothing+ ]+ return $ case catMaybes metas of+ [] -> Nothing+ name : _ -> Just name+ metaCharset :: Parser (Maybe Data.ByteString.ByteString)+ metaCharset = do+ void $ string "<meta"+ void space+ candidates <- many' $ choice+ [ do+ -- [^>Cc]++ void $ takeWhile1 $ \ c -> c /= 0x3e && c /= 0x43 && c /= 0x63+ return Nothing+ , do+ -- (?iCHARSET)+ void $ string' "CHARSET"+ -- [=]+ void $ word8 0x3d+ -- ["']?+ q <- option 0 $ satisfy $ \ c -> c == 0x22 || c == 0x27+ -- [A-Za-z0-9._-]++ charset <- takeWhile1 $ \ c ->+ 0x41 <= c && c <= 0x5a ||+ 0x61 <= c && c <= 0x7a ||+ 0x30 <= c && c <= 0x39 ||+ c == 0x2e || c == 0x5f || c == 0x2d+ when (q /= 0) $ void $ word8 q+ return $ Just charset+ , do+ -- [^>]+ void $ satisfy (/= 0x3e)+ return Nothing+ ]+ return $ case catMaybes candidates of+ [] -> Nothing+ name : _ -> Just name+ isSpace :: Word8 -> Bool+ isSpace c =+ -- [ \t\n\xff\r]+ c == 0x20 || c == 0x09 || c == 0x0a || c == 0xff || c == 0x0d+ space :: Parser Word8+ space = satisfy isSpace+ string' :: String -> Parser ()+ string' s = sequence_+ [ satisfy $ \ i ->+ toEnum (fromEnum c) == i || toEnum (fromEnum c + 32) == i+ | c <- s+ ]+ decodeAscii :: Data.ByteString.ByteString -> String+ decodeAscii =+ fmap (toEnum . fromEnum) . Data.ByteString.unpack
+ test/doctest.hs view
@@ -0,0 +1,1 @@+{-# OPTIONS_GHC -F -pgmF doctest-discover -optF test/doctest.json #-}
+ test/hlint.hs view
@@ -0,0 +1,12 @@+import Language.Haskell.HLint (hlint)+import System.Exit (exitFailure, exitSuccess)++arguments :: [String]+arguments = ["app", "src", "test"]++main :: IO ()+main = do+ hlints <- hlint arguments+ case hlints of+ [] -> exitSuccess+ _ -> exitFailure