X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FLexer.x;h=872c7aab6ccf45297197b976221cdc64ba5c759c;hp=5e6535678e11299986f21103223fd053b566e23c;hb=34c8d0312071f7d0f4d221a997d3408c653ef9e5;hpb=cb8fb4dc68b503474bd65c0a669d9018a3ce96fe

diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x
index 5e65356..872c7aa 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 }
 }
 
@@ -570,6 +580,13 @@ 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
 
@@ -1798,6 +1823,8 @@ 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
@@ -1868,13 +1897,15 @@ 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 = genericsBit `setBitIf` xopt Opt_Generics flags
 	       .|. 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