mirror of
https://github.com/GrammaticalFramework/gf-core.git
synced 2026-04-12 22:39:31 -06:00
47 lines
1.3 KiB
Haskell
47 lines
1.3 KiB
Haskell
module GF.Command.TreeOperations (
|
|
treeOp,
|
|
allTreeOps
|
|
) where
|
|
|
|
import PGF
|
|
import PGF.Data
|
|
import Data.List
|
|
|
|
type TreeOp = [Expr] -> [Expr]
|
|
|
|
treeOp :: PGF -> String -> Maybe (Either TreeOp (CId -> TreeOp))
|
|
treeOp pgf f = fmap snd $ lookup f $ allTreeOps pgf
|
|
|
|
allTreeOps :: PGF -> [(String,(String,Either TreeOp (CId -> TreeOp)))]
|
|
allTreeOps pgf = [
|
|
("compute",("compute by using semantic definitions (def)",
|
|
Left $ map (compute pgf))),
|
|
("transfer",("syntactic transfer by applying function, recursively in subtrees",
|
|
Right $ \f -> map (transfer pgf f))),
|
|
("paraphrase",("paraphrase by using semantic definitions (def)",
|
|
Left $ nub . concatMap (paraphrase pgf))),
|
|
("smallest",("sort trees from smallest to largest, in number of nodes",
|
|
Left $ smallest))
|
|
]
|
|
|
|
smallest :: [Expr] -> [Expr]
|
|
smallest = sortBy (\t u -> compare (size t) (size u)) where
|
|
size t = case t of
|
|
EAbs _ _ e -> size e + 1
|
|
EApp e1 e2 -> size e1 + size e2 + 1
|
|
_ -> 1
|
|
|
|
|
|
--- simple-minded transfer; should use PGF.Expr.match
|
|
|
|
transfer :: PGF -> CId -> Expr -> Expr
|
|
transfer pgf f e = case transf e of
|
|
v | v /= appf e -> v
|
|
_ -> case e of
|
|
EApp g a -> EApp (transfer pgf f g) (transfer pgf f a)
|
|
_ -> e
|
|
where
|
|
appf = EApp (EFun f)
|
|
transf = compute pgf . appf
|
|
|