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{
{-# LANGUAGE BangPatterns #-} -- required for versions of Alex before 2.3.4
{-# OPTIONS -w -Wwarn #-}
-- 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 Lexer (lex_tok) where
import ParserM (ParserM (..), mkT, mkTv, Token(..), St, start_code,
set_start_code,
inc_brace_depth, dec_brace_depth,
show_pos, position, input,
AlexInput, alexGetChar, alexInputPrevChar)
}
words :-
<0> $white+ ;
<0> "--" [^\n]* \n ;
"{" { \i -> do {
set_start_code in_braces;
inc_brace_depth;
mkT TOpenBrace i
}
}
"}" { \i -> do {
dec_brace_depth;
mkT TCloseBrace i
}
}
<0> "->" { mkT TArrow }
<0> "=" { mkT TEquals }
<0> "," { mkT TComma }
<0> "(" { mkT TOpenParen }
<0> ")" { mkT TCloseParen }
<0> "(#" { mkT TOpenParenHash }
<0> "#)" { mkT THashCloseParen }
<0> "section" { mkT TSection }
<0> "primop" { mkT TPrimop }
<0> "pseudoop" { mkT TPseudoop }
<0> "primtype" { mkT TPrimtype }
<0> "with" { mkT TWith }
<0> "defaults" { mkT TDefaults }
<0> "True" { mkT TTrue }
<0> "False" { mkT TFalse }
<0> "Dyadic" { mkT TDyadic }
<0> "Monadic" { mkT TMonadic }
<0> "Compare" { mkT TCompare }
<0> "GenPrimOp" { mkT TGenPrimOp }
<0> "thats_all_folks" { mkT TThatsAllFolks }
<0> [a-z][a-zA-Z0-9\#_]* { mkTv TLowerName }
<0> [A-Z][a-zA-Z0-9\#_]* { mkTv TUpperName }
<0> [0-9][0-9]* { mkTv (TInteger . read) }
<0> \" [^\"]* \" { mkTv (TString . tail . init) }
<in_braces> [^\{\}]+ { mkTv TNoBraces }
<in_braces> \n { mkTv TNoBraces }
{
get_tok :: ParserM Token
get_tok = ParserM $ \i st ->
case alexScan i (start_code st) of
AlexEOF -> Right (i, st, TEOF)
AlexError _ -> Left ("Lexical error at " ++ show_pos (position i))
AlexSkip i' _ -> case get_tok of
ParserM f -> f i' st
AlexToken i' l a -> case a $ take l $ input i of
ParserM f -> f i' st
lex_tok :: (Token -> ParserM a) -> ParserM a
lex_tok cont = get_tok >>= cont
}
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