merge GHC HEAD

[ghc-hetmet.git] / compiler / parser / Lexer.x

diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x
index bf34ee7..4ca0282 100644 (file)
--- a/compiler/parser/Lexer.x
+++ b/compiler/parser/Lexer.x
@@ -55,6 +55,7 @@ module Lexer (
    getLexState, popLexState, pushLexState,
    extension, bangPatEnabled, datatypeContextsEnabled,
    addWarning,
+   incrBracketDepth, decrBracketDepth, getParserBrakDepth,
    lexTokenStream
   ) where
 
@@ -68,7 +69,7 @@ import UniqFM
 import DynFlags
 import Module
 import Ctype
-import BasicTypes      ( InlineSpec(..), RuleMatchInfo(..) )
+import BasicTypes      ( InlineSpec(..), RuleMatchInfo(..), FractionalLit(..) )
 import Util            ( readRational )
 
 import Control.Monad
@@ -325,6 +326,15 @@ $tab+         { warn Opt_WarnTabs (text "Warning: Tab character") }
 }
 
 <0> {
+  "<[" / { ifExtension hetMetEnabled `alexAndPred` notFollowedBySymbol }
+                                       { special ITopenBrak }
+  "]>" / { ifExtension hetMetEnabled }  { special ITcloseBrak }
+  "~~" / { ifExtension hetMetEnabled }  { special ITescape }
+  "%%" / { ifExtension hetMetEnabled }  { special ITdoublePercent }
+  "~~$" / { ifExtension hetMetEnabled }  { special ITescapeDollar }
+}
+
+<0> {
   \? @varid / { ifExtension ipEnabled }        { skip_one_varid ITdupipvarid }
 }
 
@@ -536,14 +546,14 @@ data Token
   | ITchar       Char
   | ITstring     FastString
   | ITinteger    Integer
-  | ITrational   Rational
+  | ITrational   FractionalLit
 
   | ITprimchar   Char
   | ITprimstring FastString
   | ITprimint    Integer
   | ITprimword   Integer
-  | ITprimfloat  Rational
-  | ITprimdouble Rational
+  | ITprimfloat  FractionalLit
+  | ITprimdouble FractionalLit
 
   -- Template Haskell extension tokens
   | ITopenExpQuote             --  [| or [e|
@@ -567,6 +577,13 @@ data Token
   | ITLarrowtail               --  -<<
   | ITRarrowtail               --  >>-
 
+  -- Heterogeneous Metaprogramming extension
+  | ITopenBrak                 --  <[
+  | ITcloseBrak                        --  ]>
+  | ITescape                   --  ~~
+  | ITescapeDollar             --  ~~$
+  | ITdoublePercent             --  %%
+
   | ITunknown String           -- Used when the lexer can't make sense of it
   | ITeof                      -- end of file token
 
@@ -1056,9 +1073,12 @@ hexadecimal = (16,hexDigit)
 
 -- readRational can understand negative rationals, exponents, everything.
 tok_float, tok_primfloat, tok_primdouble :: String -> Token
-tok_float        str = ITrational   $! readRational str
-tok_primfloat    str = ITprimfloat  $! readRational str
-tok_primdouble   str = ITprimdouble $! readRational str
+tok_float        str = ITrational   $! readFractionalLit str
+tok_primfloat    str = ITprimfloat  $! readFractionalLit str
+tok_primdouble   str = ITprimdouble $! readFractionalLit str
+
+readFractionalLit :: String -> FractionalLit
+readFractionalLit str = (FL $! str) $! readRational str
 
 -- -----------------------------------------------------------------------------
 -- Layout processing
@@ -1520,7 +1540,8 @@ data PState = PState {
         alr_expecting_ocurly :: Maybe ALRLayout,
         -- Have we just had the '}' for a let block? If so, than an 'in'
         -- token doesn't need to close anything:
-        alr_justClosedExplicitLetBlock :: Bool
+        alr_justClosedExplicitLetBlock :: Bool,
+        code_type_bracket_depth :: Int
      }
        -- last_loc and last_len are used when generating error messages,
        -- and in pushCurrentContext only.  Sigh, if only Happy passed the
@@ -1587,6 +1608,13 @@ setExts f = P $ \s -> POk s{ extsBitmap = f (extsBitmap s) } ()
 setSrcLoc :: SrcLoc -> P ()
 setSrcLoc new_loc = P $ \s -> POk s{loc=new_loc} ()
 
+incrBracketDepth :: P ()
+incrBracketDepth = P $ \s -> POk (s{code_type_bracket_depth = (code_type_bracket_depth s)+1}) ()
+decrBracketDepth :: P ()
+decrBracketDepth = P $ \s -> POk (s{code_type_bracket_depth = (code_type_bracket_depth s)-1}) ()
+getParserBrakDepth :: P Int
+getParserBrakDepth = P $ \s -> POk s (code_type_bracket_depth s)
+
 getSrcLoc :: P SrcLoc
 getSrcLoc = P $ \s@(PState{ loc=loc }) -> POk s loc
 
@@ -1797,6 +1825,8 @@ relaxedLayoutBit :: Int
 relaxedLayoutBit = 24
 nondecreasingIndentationBit :: Int
 nondecreasingIndentationBit = 25
+hetMetBit :: Int
+hetMetBit = 31
 
 always :: Int -> Bool
 always           _     = True
@@ -1804,6 +1834,8 @@ parrEnabled :: Int -> Bool
 parrEnabled      flags = testBit flags parrBit
 arrowsEnabled :: Int -> Bool
 arrowsEnabled    flags = testBit flags arrowsBit
+hetMetEnabled :: Int -> Bool
+hetMetEnabled    flags = testBit flags hetMetBit
 thEnabled :: Int -> Bool
 thEnabled        flags = testBit flags thBit
 ipEnabled :: Int -> Bool
@@ -1865,12 +1897,14 @@ mkPState flags buf loc =
       alr_last_loc = noSrcSpan,
       alr_context = [],
       alr_expecting_ocurly = Nothing,
-      alr_justClosedExplicitLetBlock = False
+      alr_justClosedExplicitLetBlock = False,
+      code_type_bracket_depth = 0
     }
     where
       bitmap =     ffiBit            `setBitIf` xopt Opt_ForeignFunctionInterface flags
                .|. parrBit           `setBitIf` xopt Opt_ParallelArrays  flags
                .|. arrowsBit         `setBitIf` xopt Opt_Arrows          flags
+              .|. hetMetBit         `setBitIf` xopt Opt_ModalTypes      flags
                .|. thBit             `setBitIf` xopt Opt_TemplateHaskell flags
                .|. qqBit             `setBitIf` xopt Opt_QuasiQuotes     flags
                .|. ipBit             `setBitIf` xopt Opt_ImplicitParams  flags