diff options
author | David Waern <david.waern@gmail.com> | 2009-11-28 22:16:16 +0000 |
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committer | David Waern <david.waern@gmail.com> | 2009-11-28 22:16:16 +0000 |
commit | 295a27b7558cf4fae144e3cf01e488e54ca961f2 (patch) | |
tree | d549700783fdd1fe3743428278684addd7779f92 /src/Haddock/Lex.x | |
parent | fba37778cd3eb564c83f1a35e922b8a0a9f111ea (diff) |
Move H.Interface.Parse/Lex to H.Parse/Lex
These are not just used to build Interfaces.
Diffstat (limited to 'src/Haddock/Lex.x')
-rw-r--r-- | src/Haddock/Lex.x | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/src/Haddock/Lex.x b/src/Haddock/Lex.x new file mode 100644 index 00000000..04b9f0c3 --- /dev/null +++ b/src/Haddock/Lex.x @@ -0,0 +1,172 @@ +-- +-- Haddock - A Haskell Documentation Tool +-- +-- (c) Simon Marlow 2002 +-- +-- This file was modified and integrated into GHC by David Waern 2006. +-- Then moved back into Haddock by Isaac Dupree in 2009 :-) +-- + +{ +{-# OPTIONS -Wwarn -w #-} +-- The above warning supression flag is a temporary kludge. +-- While working on this module you are encouraged to remove it and fix +-- any warnings in the module. See +-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings +-- for details + +module Haddock.Lex ( + Token(..), + tokenise + ) where + +import Lexer hiding (Token) +import Parser ( parseIdentifier ) +import StringBuffer +import RdrName +import SrcLoc +import DynFlags + +import Data.Char +import Numeric +import System.IO.Unsafe +} + +$ws = $white # \n +$digit = [0-9] +$hexdigit = [0-9a-fA-F] +$special = [\"\@] +$alphanum = [A-Za-z0-9] +$ident = [$alphanum \'\_\.\!\#\$\%\&\*\+\/\<\=\>\?\@\\\\\^\|\-\~] + +:- + +-- beginning of a paragraph +<0,para> { + $ws* \n ; + $ws* \> { begin birdtrack } + $ws* [\*\-] { token TokBullet `andBegin` string } + $ws* \[ { token TokDefStart `andBegin` def } + $ws* \( $digit+ \) { token TokNumber `andBegin` string } + $ws* { begin string } +} + +-- beginning of a line +<line> { + $ws* \> { begin birdtrack } + $ws* \n { token TokPara `andBegin` para } + -- Here, we really want to be able to say + -- $ws* (\n | <eof>) { token TokPara `andBegin` para} + -- because otherwise a trailing line of whitespace will result in + -- a spurious TokString at the end of a docstring. We don't have <eof>, + -- though (NOW I realise what it was for :-). To get around this, we always + -- append \n to the end of a docstring. + () { begin string } +} + +<birdtrack> .* \n? { strtokenNL TokBirdTrack `andBegin` line } + +<string,def> { + $special { strtoken $ \s -> TokSpecial (head s) } + \<\<.*\>\> { strtoken $ \s -> TokPic (init $ init $ tail $ tail s) } + \<.*\> { strtoken $ \s -> TokURL (init (tail s)) } + \#.*\# { strtoken $ \s -> TokAName (init (tail s)) } + \/ [^\/]* \/ { strtoken $ \s -> TokEmphasis (init (tail s)) } + [\'\`] $ident+ [\'\`] { ident } + \\ . { strtoken (TokString . tail) } + "&#" $digit+ \; { strtoken $ \s -> TokString [chr (read (init (drop 2 s)))] } + "&#" [xX] $hexdigit+ \; { strtoken $ \s -> case readHex (init (drop 3 s)) of [(n,_)] -> TokString [chr n] } + -- allow special characters through if they don't fit one of the previous + -- patterns. + [\/\'\`\<\#\&\\] { strtoken TokString } + [^ $special \/ \< \# \n \'\` \& \\ \]]* \n { strtokenNL TokString `andBegin` line } + [^ $special \/ \< \# \n \'\` \& \\ \]]+ { strtoken TokString } +} + +<def> { + \] { token TokDefEnd `andBegin` string } +} + +-- ']' doesn't have any special meaning outside of the [...] at the beginning +-- of a definition paragraph. +<string> { + \] { strtoken TokString } +} + +{ +data Token + = TokPara + | TokNumber + | TokBullet + | TokDefStart + | TokDefEnd + | TokSpecial Char + | TokIdent [RdrName] + | TokString String + | TokURL String + | TokPic String + | TokEmphasis String + | TokAName String + | TokBirdTrack String +-- deriving Show + +-- ----------------------------------------------------------------------------- +-- Alex support stuff + +type StartCode = Int +type Action = String -> StartCode -> (StartCode -> [Token]) -> [Token] + +type AlexInput = (Char,String) + +alexGetChar (_, []) = Nothing +alexGetChar (_, c:cs) = Just (c, (c,cs)) + +alexInputPrevChar (c,_) = c + +tokenise :: String -> [Token] +tokenise str = let toks = go ('\n', eofHack str) para in {-trace (show toks)-} toks + where go inp@(_,str) sc = + case alexScan inp sc of + AlexEOF -> [] + AlexError _ -> error "lexical error" + AlexSkip inp' _ -> go inp' sc + AlexToken inp' len act -> act (take len str) sc (\sc -> go inp' sc) + +-- NB. we add a final \n to the string, (see comment in the beginning of line +-- production above). +eofHack str = str++"\n" + +andBegin :: Action -> StartCode -> Action +andBegin act new_sc = \str _ cont -> act str new_sc cont + +token :: Token -> Action +token t = \_ sc cont -> t : cont sc + +strtoken, strtokenNL :: (String -> Token) -> Action +strtoken t = \str sc cont -> t str : cont sc +strtokenNL t = \str sc cont -> t (filter (/= '\r') str) : cont sc +-- ^ We only want LF line endings in our internal doc string format, so we +-- filter out all CRs. + +begin :: StartCode -> Action +begin sc = \_ _ cont -> cont sc + +-- ----------------------------------------------------------------------------- +-- Lex a string as a Haskell identifier + +ident :: Action +ident str sc cont = + case strToHsQNames id of + Just names -> TokIdent names : cont sc + Nothing -> TokString str : cont sc + where id = init (tail str) + +strToHsQNames :: String -> Maybe [RdrName] +strToHsQNames str0 = + let buffer = unsafePerformIO (stringToStringBuffer str0) + pstate = mkPState buffer noSrcLoc defaultDynFlags + result = unP parseIdentifier pstate + in case result of + POk _ name -> Just [unLoc name] + _ -> Nothing +} |