X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FLexer.x;h=4ca028281ee119bb6519cc5dc37b8d8e7a8883b3;hp=a55a6310c97ac30555638bc3e1e7a2fc6bd839ea;hb=b2524b3960999fffdb3767900f58825903f6560f;hpb=18691d440f90a3dff4ef538091c886af505e5cf5

diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x
index a55a631..4ca0282 100644
--- 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
 
@@ -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 }
 }
 
@@ -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
 
@@ -1523,7 +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
@@ -1590,6 +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
 
@@ -1800,6 +1825,8 @@ relaxedLayoutBit :: Int
 relaxedLayoutBit = 24
 nondecreasingIndentationBit :: Int
 nondecreasingIndentationBit = 25
+hetMetBit :: Int
+hetMetBit = 31
 
 always :: Int -> Bool
 always           _     = True
@@ -1807,6 +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
@@ -1868,12 +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