Files
gf-core/src/runtime/haskell/PGF/Generate.hs

89 lines
2.9 KiB
Haskell

module PGF.Generate where
import PGF.CId
import PGF.Data
import PGF.Macros
import PGF.TypeCheck
import PGF.Probabilistic
import qualified Data.Map as M
import System.Random
-- generate an infinite list of trees exhaustively
generate :: PGF -> Type -> Maybe Int -> [Expr]
generate pgf ty@(DTyp _ cat _) dp = filter (\e -> case checkExpr pgf e ty of
Left _ -> False
Right _ -> True )
(concatMap (\i -> gener i cat) depths)
where
gener 0 c = [EFun f | (f, ([],_)) <- fns c]
gener i c = [
tr |
(f, (cs,_)) <- fns c,
let alts = map (gener (i-1)) cs,
ts <- combinations alts,
let tr = foldl EApp (EFun f) ts,
depth tr >= i
]
fns c = [(f,catSkeleton ty) | (f,ty) <- functionsToCat pgf c]
depths = maybe [0 ..] (\d -> [0..d]) dp
-- generate an infinite list of trees randomly
genRandom :: StdGen -> PGF -> Type -> [Expr]
genRandom = genRandomProb Nothing
genRandomProb :: Maybe Probabilities -> StdGen -> PGF -> Type -> [Expr]
genRandomProb mprobs gen pgf ty@(DTyp _ cat _) =
filter (\e -> case checkExpr pgf e ty of
Left _ -> False
Right _ -> True )
(genTrees (randomRs (0.0, 1.0 :: Double) gen) cat)
where
timeout = 47 -- give up
genTrees ds0 cat =
let (ds,ds2) = splitAt (timeout+1) ds0 -- for time out, else ds
(t,k) = genTree ds cat
in (if k>timeout then id else (t:))
(genTrees ds2 cat) -- else (drop k ds)
genTree rs = gett rs where
gett ds cid | cid == cidString = (ELit (LStr "foo"), 1)
gett ds cid | cid == cidInt = (ELit (LInt 12345), 1)
gett ds cid | cid == cidFloat = (ELit (LFlt 12345), 1)
gett [] _ = (ELit (LStr "TIMEOUT"), 1) ----
gett ds cat = case fns cat of
[] -> (EMeta 0,1)
fs -> let
d:ds2 = ds
(f,args) = getf d fs
(ts,k) = getts ds2 args
in (foldl EApp f ts, k+1)
getf d fs = case mprobs of
Just _ -> hitRegion d [(p,(f,args)) | (p,(f,args)) <- fs]
_ -> let
lg = length fs
(f,v) = snd (fs !! (floor (d * fromIntegral lg)))
in (EFun f,v)
getts ds cats = case cats of
c:cs -> let
(t, k) = gett ds c
(ts,ks) = getts (drop k ds) cs
in (t:ts, k + ks)
_ -> ([],0)
fns :: CId -> [(Double,(CId,[CId]))]
fns cat = case mprobs of
Just probs -> maybe [] id $ M.lookup cat (catProbs probs)
_ -> [(deflt,(f,(fst (catSkeleton ty)))) |
let fs = functionsToCat pgf cat,
(f,ty) <- fs,
let deflt = 1.0 / fromIntegral (length fs)]
hitRegion :: Double -> [(Double,(CId,[a]))] -> (Expr,[a])
hitRegion d vs = case vs of
(p1,(f,v1)):vs2 -> if d < p1 then (EFun f, v1) else hitRegion (d-p1) vs2
_ -> (EMeta 9,[])