{- Copyright 2016, Dominic Orchard, Andrew Rice, Mistral Contrastin, Matthew Danish Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. -} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE CPP #-} module Camfort.Helpers where import GHC.Generics import Data.Generics.Zipper import Data.Generics.Aliases import Data.Generics.Str import Data.Generics.Uniplate.Operations import Data.Data import Data.Maybe import Data.Monoid import Data.List (elemIndices, group, sort, nub) import qualified Data.ByteString.Char8 as B import System.Directory import Data.List (union) import qualified Data.Map.Lazy as Map hiding (map, (\\)) import Control.Monad.Writer.Strict -- collect: from an association list to a map with list-based bins for matching keys collect :: (Eq a, Ord k) => [(k, a)] -> Map.Map k [a] collect = Map.fromListWith union . map (fmap (:[])) type Filename = String type Directory = String type SourceText = B.ByteString type FileOrDir = String -- Filename and directory related helpers -- gets the directory part of a filename getDir :: String -> String getDir file = let ixs = elemIndices '/' file in if null ixs then file else take (last $ ixs) file {-| Creates a directory (from a filename string) if it doesn't exist -} checkDir f = case (elemIndices '/' f) of [] -> return () ix -> let d = take (last ix) f in createDirectoryIfMissing True d isDirectory :: FileOrDir -> IO Bool isDirectory s = doesDirectoryExist s -- Helpers fanout :: (a -> b) -> (a -> c) -> a -> (b, c) fanout f g x = (f x, g x) (<>) :: (a -> b) -> (a -> c) -> a -> (b, c) f <> g = fanout f g (><) :: (a -> c) -> (b -> d) -> (a, b) -> (c, d) f >< g = \(x, y) -> (f x, g y) -- Lookup functions over relation s lookups :: Eq a => a -> [(a, b)] -> [b] lookups _ [] = [] lookups x ((a, b):xs) = if (x == a) then b : lookups x xs else lookups x xs lookups' :: Eq a => a -> [((a, b), c)] -> [(b, c)] lookups' _ [] = [] lookups' x (((a, b), c):xs) = if (x == a) then (b, c) : lookups' x xs else lookups' x xs {-| Computes all pairwise combinations -} pairs :: [a] -> [(a, a)] pairs [] = [] pairs (x:xs) = (zip (repeat x) xs) ++ (pairs xs) {-| Functor composed with list functor -} mfmap :: Functor f => (a -> b) -> [f a] -> [f b] mfmap f = map (fmap f) {-| An infix `map` operation.-} each = flip (map) {-| Is the Ordering an EQ? -} cmpEq :: Ordering -> Bool cmpEq EQ = True cmpEq _ = False cmpFst :: (a -> a -> Ordering) -> (a, b) -> (a, b) -> Ordering cmpFst c (x1, y1) (x2, y2) = c x1 x2 cmpSnd :: (b -> b -> Ordering) -> (a, b) -> (a, b) -> Ordering cmpSnd c (x1, y1) (x2, y2) = c y1 y2 {-| used for type-level annotations giving documentation -} type (:?) a (b :: k) = a -- Helper function, reduces a list two elements at a time with a partial operation foldPair :: (a -> a -> Maybe a) -> [a] -> [a] foldPair f [] = [] foldPair f [a] = [a] foldPair f (a:(b:xs)) = case f a b of Nothing -> a : (foldPair f (b : xs)) Just c -> foldPair f (c : xs) class PartialMonoid x where -- Satisfies equations: -- pmappend x pmempty = Just x -- pmappend pempty x = Just x -- (pmappend y z) >>= (\w -> pmappend x w) = (pmappend x y) >>= (\w -> pmappend w z) emptyM :: x appendM :: x -> x -> Maybe x normalise :: (Ord t, PartialMonoid t) => [t] -> [t] normalise = nub . reduce . sort where reduce = foldPair appendM normaliseNoSort :: (Ord t, PartialMonoid t) => [t] -> [t] normaliseNoSort = nub . reduce where reduce = foldPair appendM normaliseBy :: Ord t => (t -> t -> Maybe t) -> [t] -> [t] normaliseBy plus = nub . (foldPair plus) . sort #if __GLASGOW_HASKELL__ < 800 instance Monoid x => Monad ((,) x) where return a = (mempty, a) (x, a) >>= k = let (x', b) = k a in (mappend x x', b) #endif -- Data-type generic reduce traversal reduceCollect :: (Data s, Data t, Uniplate t, Biplate t s) => (s -> Maybe a) -> t -> [a] reduceCollect k x = execWriter (transformBiM (\y -> do case k y of Just x -> tell [x] Nothing -> return () return y) x) -- Data-type generic comonad-style traversal with zipper (contextual traversal) everywhere :: (Zipper a -> Zipper a) -> Zipper a -> Zipper a everywhere k z = everywhere' z where everywhere' = enterRight . enterDown . k enterDown z = case (down' z) of Just dz -> let dz' = everywhere' dz in case (up $ dz') of Just uz -> uz Nothing -> dz' Nothing -> z enterRight z = case (right z) of Just rz -> let rz' = everywhere' rz in case (left $ rz') of Just lz -> lz Nothing -> rz' Nothing -> z zfmap :: Data a => (a -> a) -> Zipper (d a) -> Zipper (d a) zfmap f x = zeverywhere (mkT f) x