-----------------------------------------------------------------------------
-- |
-- Module : Haddock.Interface.ParseModuleHeader
-- Copyright : (c) Simon Marlow 2006, Isaac Dupree 2009
-- License : BSD-like
--
-- Maintainer : haddock@projects.haskell.org
-- Stability : experimental
-- Portability : portable
-----------------------------------------------------------------------------
module Haddock.Interface.ParseModuleHeader (parseModuleHeader) where
import Haddock.Types
import Haddock.Lex
import Haddock.Parse
import RdrName
import DynFlags
import Data.Char
-- -----------------------------------------------------------------------------
-- Parsing module headers
-- NB. The headers must be given in the order Module, Description,
-- Copyright, License, Maintainer, Stability, Portability, except that
-- any or all may be omitted.
parseModuleHeader :: DynFlags -> String -> Either String (HaddockModInfo RdrName, Doc RdrName)
parseModuleHeader dflags str0 =
let
getKey :: String -> String -> (Maybe String,String)
getKey key str = case parseKey key str of
Nothing -> (Nothing,str)
Just (value,rest) -> (Just value,rest)
(_moduleOpt,str1) = getKey "Module" str0
(descriptionOpt,str2) = getKey "Description" str1
(_copyrightOpt,str3) = getKey "Copyright" str2
(_licenseOpt,str4) = getKey "License" str3
(_licenceOpt,str5) = getKey "Licence" str4
(maintainerOpt,str6) = getKey "Maintainer" str5
(stabilityOpt,str7) = getKey "Stability" str6
(portabilityOpt,str8) = getKey "Portability" str7
description1 :: Either String (Maybe (Doc RdrName))
description1 = case descriptionOpt of
Nothing -> Right Nothing
-- TODO: pass real file position
Just description -> case parseString $ tokenise dflags description (0,0) of
Nothing -> Left ("Cannot parse Description: " ++ description)
Just doc -> Right (Just doc)
in
case description1 of
Left mess -> Left mess
-- TODO: pass real file position
Right docOpt -> case parseParas $ tokenise dflags str8 (0,0) of
Nothing -> Left "Cannot parse header documentation paragraphs"
Just doc -> Right (HaddockModInfo {
hmi_description = docOpt,
hmi_portability = portabilityOpt,
hmi_stability = stabilityOpt,
hmi_maintainer = maintainerOpt
}, doc)
-- | This function is how we read keys.
--
-- all fields in the header are optional and have the form
--
-- [spaces1][field name][spaces] ":"
-- [text]"\n" ([spaces2][space][text]"\n" | [spaces]"\n")*
-- where each [spaces2] should have [spaces1] as a prefix.
--
-- Thus for the key "Description",
--
-- > Description : this is a
-- > rather long
-- >
-- > description
-- >
-- > The module comment starts here
--
-- the value will be "this is a .. description" and the rest will begin
-- at "The module comment".
parseKey :: String -> String -> Maybe (String,String)
parseKey key toParse0 =
do
let
(spaces0,toParse1) = extractLeadingSpaces toParse0
indentation = spaces0
afterKey0 <- extractPrefix key toParse1
let
afterKey1 = extractLeadingSpaces afterKey0
afterColon0 <- case snd afterKey1 of
':':afterColon -> return afterColon
_ -> Nothing
let
(_,afterColon1) = extractLeadingSpaces afterColon0
return (scanKey True indentation afterColon1)
where
scanKey :: Bool -> String -> String -> (String,String)
scanKey _ _ [] = ([],[])
scanKey isFirst indentation str =
let
(nextLine,rest1) = extractNextLine str
accept = isFirst || sufficientIndentation || allSpaces
sufficientIndentation = case extractPrefix indentation nextLine of
Just (c:_) | isSpace c -> True
_ -> False
allSpaces = case extractLeadingSpaces nextLine of
(_,[]) -> True
_ -> False
in
if accept
then
let
(scanned1,rest2) = scanKey False indentation rest1
scanned2 = case scanned1 of
"" -> if allSpaces then "" else nextLine
_ -> nextLine ++ "\n" ++ scanned1
in
(scanned2,rest2)
else
([],str)
extractLeadingSpaces :: String -> (String,String)
extractLeadingSpaces [] = ([],[])
extractLeadingSpaces (s@(c:cs))
| isSpace c =
let
(spaces1,cs1) = extractLeadingSpaces cs
in
(c:spaces1,cs1)
| True = ([],s)
extractNextLine :: String -> (String,String)
extractNextLine [] = ([],[])
extractNextLine (c:cs)
| c == '\n' =
([],cs)
| True =
let
(line,rest) = extractNextLine cs
in
(c:line,rest)
-- comparison is case-insensitive.
extractPrefix :: String -> String -> Maybe String
extractPrefix [] s = Just s
extractPrefix _ [] = Nothing
extractPrefix (c1:cs1) (c2:cs2)
| toUpper c1 == toUpper c2 = extractPrefix cs1 cs2
| True = Nothing