Founding the newly structured GF2.0 cvs archive.

src/GF/UseGrammar/Randomized.hs

@@ -0,0 +1,47 @@
+module Randomized where
+
+import Abstract
+import Editing
+
+import Operations
+import Zipper
+
+--- import Arch (myStdGen) --- circular for hbc
+import Random --- (mkStdGen, StdGen, randoms) --- bad import for hbc
+
+-- random generation and refinement. AR 22/8/2001
+-- implemented as sequence of refinement menu selecsions, encoded as integers
+
+myStdGen = mkStdGen ---
+
+-- build one random tree; use mx to prevent infinite search
+mkRandomTree :: StdGen -> Int -> CGrammar -> QIdent -> Err Tree
+mkRandomTree gen mx gr cat = mkTreeFromInts (take mx (randoms gen)) gr cat
+
+refineRandom :: StdGen -> Int -> CGrammar -> Action
+refineRandom gen mx = mkStateFromInts $ take mx $ map abs (randoms gen)
+
+-- build a tree from a list of integers
+mkTreeFromInts :: [Int] -> CGrammar -> QIdent -> Err Tree
+mkTreeFromInts ints gr cat = do
+  st0   <- newCat gr cat initState
+  state <- mkStateFromInts ints gr st0
+  return $ loc2tree state
+
+mkStateFromInts :: [Int] -> CGrammar -> Action
+mkStateFromInts ints gr = mkRandomState ints where
+  mkRandomState [] state = do
+    testErr (isCompleteState state) "not completed"
+    return state
+  mkRandomState (n:ns) state = do 
+    let refs = refinementsState gr state
+    testErr (not (null refs)) $ "no refinements available for" +++ 
+                                              prt (actVal state)
+    (ref,_) <- (refs !? (n `mod` (length refs)))
+    state1  <- refineWithAtom False gr ref state
+    if isCompleteState state1 
+       then return state1
+       else do 
+         state2  <- goNextMeta state1
+	 mkRandomState ns state2
+