{-# LANGUAGE
- BangPatterns
- , UnicodeSyntax
+ UnicodeSyntax
#-}
--- |MIME Type guessing by a file extension. This is a poor man's way
--- of guessing MIME Types. It is simple and fast.
+-- |Guessing MIME Types by file extensions. It's not always accurate
+-- but simple and fast.
--
-- In general you don't have to use this module directly.
module Network.HTTP.Lucu.MIMEType.Guess
)
where
import Control.Applicative
+import Control.Monad
import qualified Data.Ascii as A
import Data.Attoparsec.Char8 as P
import qualified Data.Attoparsec.Lazy as LP
import qualified Data.Map as M
import Data.Map (Map)
import Data.Maybe
+import Data.Monoid.Unicode
import Data.Text (Text)
import qualified Data.Text as T
import Data.Text.Encoding
-import Language.Haskell.Pretty
-import Language.Haskell.Syntax
+import Language.Haskell.Exts.Build
+import Language.Haskell.Exts.Extension
+import Language.Haskell.Exts.Pretty
+import Language.Haskell.Exts.Syntax
import Network.HTTP.Lucu.MIMEType
import Prelude.Unicode
import System.FilePath
--- |'Map' from extension to 'MIMEType'.
+-- |A 'Map' from file extensions to 'MIMEType's.
type ExtMap = Map Text MIMEType
--- |Guess the MIME Type of file.
+-- |Guess the MIME Type of a file.
guessTypeByFileName ∷ ExtMap → FilePath → Maybe MIMEType
-guessTypeByFileName !extMap !fpath
- = let ext = T.pack $ takeExtension fpath
- in
- M.lookup ext extMap
+guessTypeByFileName extMap fpath
+ = case takeExtension fpath of
+ [] → Nothing
+ (_:ext) → M.lookup (T.pack ext) extMap
-- |Read an Apache mime.types and parse it.
parseExtMapFile ∷ FilePath → IO ExtMap
parseExtMapFile fpath
= do file ← B.readFile fpath
case LP.parse extMapP file of
- LP.Done _ xs → return $ compile xs
- LP.Fail _ _ e → fail ("Failed to parse: " ⧺ fpath ⧺ ": " ⧺ e)
+ LP.Done _ xs
+ → case compile xs of
+ Right m → return m
+ Left e → fail (concat [ "Duplicate extension \""
+ , show e
+ , "\" in: "
+ , fpath
+ ])
+ LP.Fail _ _ e
+ → fail ("Failed to parse: " ⧺ fpath ⧺ ": " ⧺ e)
extMapP ∷ Parser [ (MIMEType, [Text]) ]
-extMapP = do xs ← P.many (comment <|> validLine <|> emptyLine)
+extMapP = do xs ← P.many (try comment <|> try validLine <|> emptyLine)
endOfInput
return $ catMaybes xs
where
isSpc c = c ≡ '\x20' ∨ c ≡ '\x09'
comment ∷ Parser (Maybe (MIMEType, [Text]))
- comment = try $
- do skipWhile isSpc
- _ ← char '#'
+ comment = do skipWhile isSpc
+ void $ char '#'
skipWhile (≢ '\x0A')
return Nothing
validLine ∷ Parser (Maybe (MIMEType, [Text]))
- validLine = try $
- do skipWhile isSpc
- mime ← mimeTypeP
+ validLine = do skipWhile isSpc
+ mime ← mimeType
skipWhile isSpc
exts ← sepBy extP (skipWhile isSpc)
return $ Just (mime, exts)
extP = decodeUtf8 <$> takeWhile1 (\c → (¬) (isSpc c ∨ c ≡ '\x0A'))
emptyLine ∷ Parser (Maybe (MIMEType, [Text]))
- emptyLine = try $
- do skipWhile isSpc
- _ ← char '\x0A'
+ emptyLine = do skipWhile isSpc
+ void $ char '\x0A'
return Nothing
-compile ∷ [ (MIMEType, [Text]) ] → Map Text MIMEType
-compile = M.fromList ∘ concat ∘ map tr
+compile ∷ Ord k ⇒ [(v, [k])] → Either (k, v, v) (Map k v)
+compile = go (∅) ∘ concat ∘ map tr
where
- tr ∷ (MIMEType, [Text]) → [ (Text, MIMEType) ]
- tr (mime, exts) = [ (ext, mime) | ext ← exts ]
+ tr ∷ (v, [k]) → [(k, v)]
+ tr (v, ks) = [(k, v) | k ← ks]
+
+ go ∷ Ord k ⇒ Map k v → [(k, v)] → Either (k, v, v) (Map k v)
+ go m [] = Right m
+ go m ((k, v):xs)
+ = case M.insertLookupWithKey' f k v m of
+ (Nothing, m') → go m' xs
+ (Just v0, _ ) → Left (k, v0, v)
+
+ f ∷ k → v → v → v
+ f _ _ = id
-- |@'serializeExtMap' extMap moduleName variableName@ generates a
-- Haskell source code which contains the following things:
--
-- * A definition of module named @moduleName@.
--
--- * @variableName ∷ 'ExtMap'@ whose content is a serialization of
--- @extMap@.
+-- * @variableName :: 'ExtMap'@ whose content is the serialised
+-- @extMap@.
--
-- The module "Network.HTTP.Lucu.MIMEType.DefaultExtensionMap" is
-- surely generated using this function.
serializeExtMap ∷ ExtMap → String → String → String
serializeExtMap extMap moduleName variableName
- = let hsModule = HsModule (⊥) modName (Just exports) imports decls
- modName = Module moduleName
- exports = [HsEVar (UnQual (HsIdent variableName))]
- imports = [ HsImportDecl (⊥) (Module "Network.HTTP.Lucu.MIMEType") False Nothing Nothing
- , HsImportDecl (⊥) (Module "Network.HTTP.Lucu.MIMEType.Guess") False Nothing Nothing
- , HsImportDecl (⊥) (Module "Data.Ascii") True (Just (Module "A")) Nothing
- , HsImportDecl (⊥) (Module "Data.Map") True (Just (Module "M")) Nothing
- , HsImportDecl (⊥) (Module "Data.Text") True (Just (Module "T")) Nothing
- ]
- decls = [ HsTypeSig (⊥) [HsIdent variableName]
- (HsQualType []
- (HsTyCon (UnQual (HsIdent "ExtMap"))))
- , HsFunBind [HsMatch (⊥) (HsIdent variableName)
- [] (HsUnGuardedRhs extMapExp) []]
- ]
- extMapExp = HsApp (HsVar (Qual (Module "M") (HsIdent "fromList"))) (HsList records)
- comment = "{- !!! WARNING !!!\n"
- ⧺ " This file is automatically generated.\n"
- ⧺ " DO NOT EDIT BY HAND OR YOU WILL REGRET -}\n\n"
+ = let hsModule = Module (⊥) (ModuleName moduleName) modPragma
+ Nothing (Just exports) imports decls
+ modPragma = [ LanguagePragma (⊥) [ name (show OverloadedStrings) ] ]
+ exports = [ EVar (UnQual (name variableName)) ]
+ imports = [ ImportDecl (⊥) (ModuleName "Network.HTTP.Lucu.MIMEType")
+ False False Nothing Nothing Nothing
+ , ImportDecl (⊥) (ModuleName "Network.HTTP.Lucu.MIMEType.Guess")
+ False False Nothing Nothing Nothing
+ , ImportDecl (⊥) (ModuleName "Data.Ascii")
+ False False Nothing Nothing (Just (False, []))
+ , ImportDecl (⊥) (ModuleName "Data.Map")
+ True False Nothing (Just (ModuleName "M")) Nothing
+ ]
+ decls = [ TypeSig (⊥) [name variableName]
+ (TyCon (UnQual (name "ExtMap")))
+ , nameBind (⊥) (name variableName) extMapExp
+ , InlineSig (⊥) False AlwaysActive (UnQual (name variableName))
+ ]
+ comment = concat [ "{- !!! WARNING !!!\n"
+ , " This file is automatically generated.\n"
+ , " DO NOT EDIT BY HAND OR YOU WILL REGRET -}\n\n"
+ ]
+ extMapExp = qvar (ModuleName "M") (name "fromList") `app` listE records
in
comment ⧺ prettyPrint hsModule ⧺ "\n"
where
- records ∷ [HsExp]
+ records ∷ [Exp]
records = map record $ M.assocs extMap
- record ∷ (Text, MIMEType) → HsExp
+ record ∷ (Text, MIMEType) → Exp
record (ext, mime)
- = HsTuple
- [ HsApp (HsVar (Qual (Module "T") (HsIdent "pack")))
- (HsLit (HsString (T.unpack ext)))
- , mimeToExp mime
- ]
-
- mimeToExp ∷ MIMEType → HsExp
- mimeToExp mt
- = HsApp (HsVar (UnQual (HsIdent "parseMIMEType")))
- (HsParen
- (HsApp (HsVar (Qual (Module "A") (HsIdent "unsafeFromString")))
- (HsLit (HsString $ mimeToString mt))))
+ = tuple [ strE (T.unpack ext)
+ , function "parseMIMEType" `app` strE (mimeToString mime)
+ ]
mimeToString ∷ MIMEType → String
mimeToString = A.toString ∘ A.fromAsciiBuilder ∘ printMIMEType
projects / Lucu.git / blobdiff