"{-#" $whitechar* (INCLUDE|include) { lex_string_prag ITinclude_prag }
}
+<0,option_prags,glaexts> {
+ -- This is to catch things like {-# OPTIONS OPTIONS_HUGS ...
+ "{-#" $whitechar* $idchar+ { nested_comment }
+}
+
-- '0' state: ordinary lexemes
-- 'glaexts' state: glasgow extensions (postfix '#', etc.)
<0,glaexts> {
\? @varid / { ifExtension ipEnabled } { skip_one_varid ITdupipvarid }
- \% @varid / { ifExtension ipEnabled } { skip_one_varid ITsplitipvarid }
}
<glaexts> {
| ITccallconv
| ITdotnet
| ITmdo
+ | ITiso
+ | ITfamily
-- Pragmas
| ITinline_prag Bool -- True <=> INLINE, False <=> NOINLINE
| ITqconsym (FastString,FastString)
| ITdupipvarid FastString -- GHC extension: implicit param: ?x
- | ITsplitipvarid FastString -- GHC extension: implicit param: %x
| ITpragma StringBuffer
isSpecial ITccallconv = True
isSpecial ITstdcallconv = True
isSpecial ITmdo = True
+isSpecial ITiso = True
+isSpecial ITfamily = True
isSpecial _ = False
-- the bitmap provided as the third component indicates whether the
( "forall", ITforall, bit tvBit),
( "mdo", ITmdo, bit glaExtsBit),
+ ( "family", ITfamily, bit idxTysBit),
( "foreign", ITforeign, bit ffiBit),
( "export", ITexport, bit ffiBit),
,("-", ITminus, 0)
,("!", ITbang, 0)
- ,("*", ITstar, bit glaExtsBit) -- For data T (a::*) = MkT
- ,(".", ITdot, bit tvBit) -- For 'forall a . t'
+ ,("*", ITstar, bit glaExtsBit .|.
+ bit idxTysBit) -- For data T (a::*) = MkT
+ ,(".", ITdot, bit tvBit) -- For 'forall a . t'
,("-<", ITlarrowtail, bit arrowsBit)
,(">-", ITrarrowtail, bit arrowsBit)
,("→", ITrarrow, bit glaExtsBit)
,("←", ITlarrow, bit glaExtsBit)
,("⋯", ITdotdot, bit glaExtsBit)
+ -- ToDo: ideally, → and ∷ should be "specials", so that they cannot
+ -- form part of a large operator. This would let us have a better
+ -- syntax for kinds: ɑ∷*→* would be a legal kind signature. (maybe).
#endif
]
tvBit = 7 -- Scoped type variables enables 'forall' keyword
bangPatBit = 8 -- Tells the parser to understand bang-patterns
-- (doesn't affect the lexer)
+idxTysBit = 9 -- indexed type families: 'family' keyword and kind sigs
glaExtsEnabled, ffiEnabled, parrEnabled :: Int -> Bool
glaExtsEnabled flags = testBit flags glaExtsBit
ipEnabled flags = testBit flags ipBit
tvEnabled flags = testBit flags tvBit
bangPatEnabled flags = testBit flags bangPatBit
+idxTysEnabled flags = testBit flags idxTysBit
-- PState for parsing options pragmas
--
.|. ipBit `setBitIf` dopt Opt_ImplicitParams flags
.|. tvBit `setBitIf` dopt Opt_ScopedTypeVariables flags
.|. bangPatBit `setBitIf` dopt Opt_BangPatterns flags
+ .|. idxTysBit `setBitIf` dopt Opt_IndexedTypes flags
--
setBitIf :: Int -> Bool -> Int
b `setBitIf` cond | cond = bit b
span `seq` setLastToken span bytes
t span buf bytes
--- ToDo: Alex reports the buffer at the start of the erroneous lexeme,
--- but it would be more informative to report the location where the
--- error was actually discovered, especially if this is a decoding
--- error.
-reportLexError loc1 loc2 buf str =
+reportLexError loc1 loc2 buf str
+ | atEnd buf = failLocMsgP loc1 loc2 (str ++ " at end of input")
+ | otherwise =
let
c = fst (nextChar buf)
in
if c == '\0' -- decoding errors are mapped to '\0', see utf8DecodeChar#
- then failLocMsgP loc2 loc2 "UTF-8 decoding error"
+ then failLocMsgP loc2 loc2 (str ++ " (UTF-8 decoding error)")
else failLocMsgP loc1 loc2 (str ++ " at character " ++ show c)
}