prog_synthesis/02.hs

212 lines
11 KiB
Haskell

import Data.List (elemIndex, sort, find)
import Data.Maybe (isJust)
infixl 4 :+:
data Expr = Zero
| Succ Expr
| Len Expr
| FirstZero Expr
| Sort Expr
| SubList Expr Expr Expr
| Expr :+: Expr
| Recursive Expr
| ZeroList
| InList
deriving (Read, Show, Eq)
data Type = IntT | ListT
deriving (Read, Show, Eq)
data Value = IntV Int | ListV [Int]
deriving (Read, Show, Eq)
typeOf :: Expr -> Type
typeOf Zero = IntT
typeOf (Succ {}) = IntT
typeOf (Len {}) = IntT
typeOf (FirstZero {}) = IntT
typeOf _ = ListT
data Env = Env {input :: [Int], prog :: Expr, steps :: Int}
stepInEnv :: Env -> Env
stepInEnv env@(Env {input, prog, steps}) = env { steps = steps - 1 }
execInt :: Env -> Expr -> Maybe Int
execInt (Env {input, prog, steps=0}) _ = Nothing
execInt _ Zero = Just 0
execInt env (Succ expr) = (+) 1 <$> execInt (stepInEnv env) expr
execInt env (Len listExpr) = length <$> execList (stepInEnv env) listExpr
execInt env (FirstZero listExpr) = do value <- execList (stepInEnv env) listExpr
0 `elemIndex` value
execInt _ _ = Nothing
execList :: Env -> Expr -> Maybe [Int]
execList (Env {input, prog, steps=0}) _ = Nothing
execList env (Sort listExpr) = sort <$> execList (stepInEnv env) listExpr
execList env (SubList listExpr exprFrom exprTo) = do valFrom <- execInt (stepInEnv env) exprFrom
valTo <- execInt (stepInEnv env) exprTo
listValue <- execList (stepInEnv env) listExpr
return $ drop valFrom $ take (valTo + 1) listValue
execList env (exprLeft :+: exprRight) = do valLeft <- execList (stepInEnv env) exprLeft
valRight <- execList (stepInEnv env) exprRight
return $ valLeft ++ valRight
execList env (Recursive listExpr) = do listValue <- execList (stepInEnv env) listExpr
if null listValue then Just [] else execList (stepInEnv $ env {input = listValue}) (prog env)
execList _ ZeroList = Just [0]
execList (Env {input, prog, steps}) InList = Just input
execList _ _ = Nothing
-- TODO: union
execProg :: [Int] -> Expr -> Maybe [Int]
execProg input expr = execList (Env {input, prog=expr, steps=20}) expr
terminals :: [Expr]
terminals = [Zero, ZeroList, InList,
Len InList, FirstZero InList, Succ Zero]
concatShuffle :: [[Expr]] -> [Expr]
concatShuffle xxs = let xxs' = filter (not . null) xxs in
if null xxs' then [] else
map head xxs' ++ concatShuffle (map tail xxs')
nextSimpleExprsLists :: [Expr] -> [[Expr]]
nextSimpleExprsLists exprs = [[Succ e | e <- exprs, typeOf e == IntT],
[Sort e | e <- exprs, typeOf e == ListT],
[Recursive e | e <- exprs, typeOf e == ListT],
[FirstZero e | e <- exprs, typeOf e == ListT],
[Len e | e <- exprs, typeOf e == ListT]]
nextExprsLists :: [Expr] -> [[Expr]]
nextExprsLists exprs = nextSimpleExprsLists exprs ++
[[e :+: e' | e <- exprs, typeOf e == ListT,
e' <- exprs, typeOf e' == ListT],
[SubList e from to | e <- exprs, typeOf e == ListT,
from <- exprs, typeOf from == IntT,
to <- exprs, typeOf to == IntT]]
nextSimpleExprs :: [Expr] -> [Expr]
nextSimpleExprs exprs = (++) exprs $ concatShuffle $ nextSimpleExprsLists exprs
nextExprs :: [Expr] -> [Expr]
nextExprs exprs = (++) exprs $ concatShuffle $ nextExprsLists exprs
-- NOTE: slower version due to additional elem checks
-- nextExprsLists' :: [Expr] -> [Expr] -> [[Expr]]
-- nextExprsLists' prevExprs allExprs = nextSimpleExprsLists prevExprs ++
-- [[e :+: e' | e <- allExprs, typeOf e == ListT,
-- e' <- allExprs, typeOf e' == ListT,
-- e `elem` prevExprs || e' `elem` prevExprs],
-- [SubList e from to | e <- allExprs, typeOf e == ListT,
-- from <- allExprs, typeOf from == IntT,
-- to <- allExprs, typeOf to == IntT,
-- e `elem` prevExprs || from `elem` prevExprs || to `elem` prevExprs]]
nextSimpleExprs' :: [Expr] -> [Expr]
nextSimpleExprs' = concatShuffle . nextSimpleExprsLists
-- TODO: check formula for three args
nextExprsLists' :: [Expr] -> [Expr] -> [[Expr]]
nextExprsLists' prevExprs allExprs = nextSimpleExprsLists prevExprs ++
[[e :+: e' | e <- prevExprs, typeOf e == ListT,
e' <- allExprs, typeOf e' == ListT],
[e :+: e' | e <- allExprs, typeOf e == ListT, e `notElem` prevExprs,
e' <- prevExprs, typeOf e' == ListT],
[SubList e from to | e <- prevExprs, typeOf e == ListT,
from <- allExprs, typeOf from == IntT,
to <- allExprs, typeOf to == IntT],
[SubList e from to | e <- allExprs, typeOf e == ListT, e `notElem` prevExprs,
from <- prevExprs, typeOf from == IntT,
to <- allExprs, typeOf to == IntT],
[SubList e from to | e <- allExprs, typeOf e == ListT, e `notElem` prevExprs,
from <- allExprs, typeOf from == IntT, from `notElem` prevExprs,
to <- prevExprs, typeOf to == IntT]]
nextExprs' :: [Expr] -> [Expr] -> [Expr]
nextExprs' prevExprs allExprs = concatShuffle $ nextExprsLists' prevExprs allExprs
-- -- do not repeat exprs
-- nextExprs' :: [Expr] -> [Expr] -> [Expr]
-- nextExprs' prevExprs allExprs = concatShuffle $ [[Succ e | e <- prevExprs, typeOf e == IntT]] ++
-- [[Sort e, Recursive e, FirstZero e, Len e] | e <- prevExprs, typeOf e == ListT]
-- ++ [[left :+: right |
-- left <- prevExprs, typeOf left == ListT,
-- right <- allExprs, typeOf right == ListT],
-- [left :+: right |
-- left <- allExprs, typeOf left == ListT, ,
-- right <- prevExprs, typeOf right == ListT],
-- [SubList e from to |
-- e <- exprs, typeOf e == ListT,
-- from <- prevExprs, typeOf from == IntT,
-- to <- allExprs, typeOf to == IntT],
-- [SubList InList from to |
-- from <- allExprs, typeOf from == IntT, from `notElem` prevExprs,
-- to <- prevExprs, typeOf to == IntT]]
data Example = Example {exampleInput :: [Int], exampleOutput :: [Int]}
-- check expr on all examples
isCorrect :: [Example] -> Expr -> Bool
isCorrect examples expr = all (\Example {exampleInput, exampleOutput} -> execProg exampleInput expr == Just exampleOutput) examples
isValid :: [Example] -> Expr -> Bool
isValid examples expr | typeOf expr == IntT = True
| otherwise = all (\Example {exampleInput, exampleOutput} -> isJust $ execProg exampleInput expr) examples
-- check are exprs produce same results on all the examples
areSame :: [Example] -> Expr -> Expr -> Bool
areSame examples exprLeft exprRight | typeOf exprLeft == IntT = False
| typeOf exprRight == IntT = False
| otherwise = all (\Example {exampleInput, exampleOutput} -> execProg exampleInput exprLeft == execProg exampleInput exprRight ) examples
-----
upSyntesisStep :: [Example] -> [Expr] -> Either [Expr] Expr
upSyntesisStep examples exprs = case find (isCorrect examples) exprs of
Just answer -> Right answer
Nothing -> let exprs' = filter (isValid examples) exprs in -- exclude invalid fragments
-- let exprs'' = foldl (\acc expr -> if any (areSame examples expr) acc then acc else expr : acc) [] exprs' in -- merge same values
Left $ nextExprs exprs'
upSyntesisRec :: [Example] -> Int -> [Expr] -> Maybe Expr
upSyntesisRec _ 0 _ = Nothing
upSyntesisRec examples steps exprs = case upSyntesisStep examples exprs of
Right answer -> Just answer
Left exprs' -> upSyntesisRec examples (steps - 1) exprs'
upSyntesis :: [Example] -> Int -> Maybe Expr
upSyntesis examples steps = upSyntesisRec examples steps terminals
-----
upSyntesisStep' :: [Example] -> [Expr] -> [Expr] -> Either [Expr] Expr
upSyntesisStep' examples prevExprs allExprs =
case find (isCorrect examples) prevExprs of
Just answer -> Right answer
Nothing -> let allExprs' = filter (isValid examples) allExprs in -- exclude invalid fragments
let prevExprs' = filter (isValid examples) prevExprs in -- exclude invalid fragments
-- let allExprs'' = foldl (\acc expr -> if any (areSame examples expr) acc then acc else expr : acc) [] allExprs' in -- merge same values
-- let prevExprs'' = foldl (\acc expr -> if any (areSame examples expr) acc then acc else expr : acc) [] prevExprs' in -- merge same values
Left $ nextExprs' prevExprs' allExprs'
upSyntesisRec' :: [Example] -> Int -> [Expr] -> [Expr] -> Maybe Expr
upSyntesisRec' _ 0 _ _ = Nothing
upSyntesisRec' examples steps prevExprs allExprs = case upSyntesisStep' examples prevExprs allExprs of
Right answer -> Just answer
Left exprs -> upSyntesisRec' examples (steps - 1) exprs (allExprs ++ exprs)
upSyntesis' :: [Example] -> Int -> Maybe Expr
upSyntesis' examples steps = upSyntesisRec' examples steps terminals terminals
-----
exampleOf :: [Int] -> [Int] -> Example
exampleOf input output = Example {exampleInput = input, exampleOutput = output}
sameExamplesExpected = InList
sameExamples = [exampleOf [1] [1], exampleOf [1,2] [1,2], exampleOf [1,2,3] [1,2,3], exampleOf [1,2,3,4] [1,2,3,4]]
revExamplesExpected = Recursive (SubList InList (Succ Zero) (Len InList)) :+: SubList InList Zero Zero
revExamples = [exampleOf [1] [1], exampleOf [1,2] [2,1], exampleOf [1,2,3] [3,2,1], exampleOf [1,2,3,4] [4,3,2,1]]
main = print $ upSyntesis' revExamples 4