Changeset 7035 for src/Pugs/AST/Internals.hs

Timestamp:

09/17/05 22:55:58 (3 years ago)

Author:

gaal

Message:

Lexical pragmas (WIP). See Pugs.AST.Prag. Dominus++.
This doesn't work yet, my pragmas got lost somewhere between the parser
and the evaluator.
TODO after it's fixed:
- throw away the cons list in favor of a primitive [] - it's enough
- figure out how to install other kinds of pragma data, not just Int

And, the fun part:
- use fatal
- use sort 'mergesort'
- no strict :-)
- other ideas from http://perl.plover.com/TPF/Pragmas/PROPOSAL

Files:

• src/Pugs/AST/Internals.hs (modified) (6 diffs)

src/Pugs/AST/Internals.hs

@@ -9 +9 @@
     Val(..),   -- uses V.* (which ones?)
     Value(..), -- uses Val, Eval
+    InitDat(..),
 
     EvalT(..), ContT(..),
@@ -79 +80 @@
 
 import Pugs.Parser.Number
+import Pugs.AST.Prag
 import Pugs.AST.Pos
 import Pugs.AST.Scope
@@ -862 +864 @@
     | Cxt !Cxt !Exp                     -- ^ Context
     | Pos !Pos !Exp                     -- ^ Position
+    | Prag !Pragmas !Exp                -- ^ Lexical pragmas
     | Pad !Scope !Pad !Exp              -- ^ Lexical pad
     | Sym !Scope !Var !Exp              -- ^ Symbol declaration
@@ -904 +907 @@
     unwrap (Cxt _ exp)      = unwrap exp
     unwrap (Pos _ exp)      = unwrap exp
+    unwrap (Prag _ exp)     = unwrap exp
     unwrap (Pad _ _ exp)    = unwrap exp
     unwrap (Sym _ _ exp)    = unwrap exp
@@ -954 +958 @@
     | otherwise
     = (Var name, vs)
+extract (Prag prag ex) vs = ((Prag prag ex'), vs')
+    where
+    (ex', vs') = extract ex vs
 extract (Pos pos ex) vs = ((Pos pos ex'), vs')
     where
@@ -1043 +1050 @@
     , envDebug   :: !DebugInfo           -- ^ Debug info map
     , envPos     :: !Pos                 -- ^ Source position range
+    , envPragmas :: !Pragmas             -- ^ List of pragmas in effect
+    , envInitDat :: !(TVar InitDat)      -- ^ BEGIN result information
+    } deriving (Show, Eq, Ord, Typeable)
+
+{-|
+Module initialization information.
+
+When a module is loaded and initialized (i.e., its &import routine is
+called), it may need to communicate information back to the parser. 
+This information is held in a TVar to which the parser has access.
+Currently we use this for keeping track of lexical pragma change
+requests, but the possiblyExit mechanism may be refactored to use
+this as well.
+-}
+data InitDat = MkInitDat
+    { initPragmas :: [Pragma]            -- ^ Pragma values being installed
     } deriving (Show, Eq, Ord, Typeable)