a major refactoring in the C and the Haskell runtimes. Note incompatible change in the PGF format!!!

The following are the outcomes:

   - Predef.nonExist is fully supported by both the Haskell and the C runtimes

   - Predef.BIND is now an internal compiler defined token. For now
     it behaves just as usual for the Haskell runtime, i.e. it generates &+.
     However, the special treatment will let us to handle it properly in 
     the C runtime.

   - This required a major change in the PGF format since both 
     nonExist and BIND may appear inside 'pre' and this was not supported
     before.

1 files changed, 7 insertions, 3 deletions

diff --git a/src/runtime/haskell/PGF/Optimize.hs b/src/runtime/haskell/PGF/Optimize.hs
index a339c9add..f04a8b04c 100644
--- a/src/runtime/haskell/PGF/Optimize.hs
+++ b/src/runtime/haskell/PGF/Optimize.hs
@@ -221,9 +221,13 @@ splitLexicalRules cnc p_prods =
         
         wf ts = (ts,IntSet.singleton funid)
         
-        seq2prefix []                   = TrieMap.fromList [wf []]
-        seq2prefix (SymKS ts     :syms) = TrieMap.fromList [wf ts]
-        seq2prefix (SymKP ts alts:syms) = TrieMap.fromList (wf ts : [wf ts | Alt ts ps <- alts])
+        seq2prefix []                      = TrieMap.fromList [wf []]
+        seq2prefix (SymKS t         :syms) = TrieMap.fromList [wf [t]]
+        seq2prefix (SymKP syms0 alts:syms) = TrieMap.unionsWith IntSet.union
+                                                (seq2prefix (syms0++syms) : 
+                                                  [seq2prefix (syms1 ++ syms) | (syms1,ps) <- alts])
+        seq2prefix (SymNE           :syms) = TrieMap.empty
+        seq2prefix (SymBIND         :syms) = TrieMap.fromList [wf ["&+"]]
 
 updateConcrete abs cnc = 
   let p_prods0      = filterProductions IntMap.empty IntSet.empty (productions cnc)