mirror of
https://github.com/GrammaticalFramework/gf-core.git
synced 2026-04-09 04:59:31 -06:00
40 lines
1.3 KiB
Haskell
40 lines
1.3 KiB
Haskell
module GF.Command.TreeOperations (
|
|
treeOp,
|
|
allTreeOps,
|
|
) where
|
|
|
|
import PGF2(Expr,PGF,Fun,compute,mkApp,unApp,unMeta,exprSize,exprFunctions)
|
|
import Data.List
|
|
|
|
type TreeOp = [Expr] -> [Expr]
|
|
|
|
treeOp :: PGF -> String -> Maybe (Either TreeOp (Fun -> TreeOp))
|
|
treeOp pgf f = fmap snd $ lookup f $ allTreeOps pgf
|
|
|
|
allTreeOps :: PGF -> [(String,(String,Either TreeOp (Fun -> TreeOp)))]
|
|
allTreeOps pgf = [
|
|
("compute",("compute by using semantic definitions (def)",
|
|
Left $ map (compute pgf))),
|
|
("largest",("sort trees from largest to smallest, in number of nodes",
|
|
Left $ largest)),
|
|
("nub",("remove duplicate trees",
|
|
Left $ nub)),
|
|
("smallest",("sort trees from smallest to largest, in number of nodes",
|
|
Left $ smallest)),
|
|
("subtrees",("return all fully applied subtrees (stopping at abstractions), by default sorted from the largest",
|
|
Left $ concatMap subtrees)),
|
|
("funs",("return all fun functions appearing in the tree, with duplications",
|
|
Left $ \es -> [mkApp f [] | e <- es, f <- exprFunctions e]))
|
|
]
|
|
|
|
largest :: [Expr] -> [Expr]
|
|
largest = reverse . smallest
|
|
|
|
smallest :: [Expr] -> [Expr]
|
|
smallest = sortBy (\t u -> compare (exprSize t) (exprSize u))
|
|
|
|
subtrees :: Expr -> [Expr]
|
|
subtrees t = t : case unApp t of
|
|
Just (f,ts) -> concatMap subtrees ts
|
|
_ -> [] -- don't go under abstractions
|