diff options
Diffstat (limited to 'src/Language/Haskell/Stylish/Util.hs')
| -rw-r--r-- | src/Language/Haskell/Stylish/Util.hs | 71 |
1 files changed, 52 insertions, 19 deletions
diff --git a/src/Language/Haskell/Stylish/Util.hs b/src/Language/Haskell/Stylish/Util.hs index 004c3f1..ed5de91 100644 --- a/src/Language/Haskell/Stylish/Util.hs +++ b/src/Language/Haskell/Stylish/Util.hs @@ -1,23 +1,27 @@ -------------------------------------------------------------------------------- module Language.Haskell.Stylish.Util ( nameToString + , isOperator , indent , padRight , everything , infoPoints , wrap + , wrapRest , withHead - , withLast , withInit + , withTail + , withLast ) where -------------------------------------------------------------------------------- import Control.Arrow ((&&&), (>>>)) +import Data.Char (isAlpha) import Data.Data (Data) import qualified Data.Generics as G -import Data.Maybe (maybeToList) +import Data.Maybe (fromMaybe, listToMaybe, maybeToList) import Data.Typeable (cast) import qualified Language.Haskell.Exts.Annotated as H @@ -33,8 +37,19 @@ nameToString (H.Symbol _ str) = str -------------------------------------------------------------------------------- +isOperator :: H.Name l -> Bool +isOperator = fromMaybe False + . (fmap (not . isAlpha) . listToMaybe) + . nameToString + +-------------------------------------------------------------------------------- indent :: Int -> String -> String -indent len str = replicate len ' ' ++ str +indent len = (indentPrefix len ++) + + +-------------------------------------------------------------------------------- +indentPrefix :: Int -> String +indentPrefix = (`replicate` ' ') -------------------------------------------------------------------------------- @@ -58,21 +73,34 @@ wrap :: Int -- ^ Maximum line width -> Int -- ^ Indentation -> [String] -- ^ Strings to add/wrap -> Lines -- ^ Resulting lines -wrap maxWidth leading ind strs = - let (ls, curr, _) = foldl step ([], leading, length leading) strs - in ls ++ [curr] +wrap maxWidth leading ind = wrap' leading where - -- TODO: In order to optimize this, use a difference list instead of a - -- regular list for 'ls'. - step (ls, curr, width) str - | nextLine = (ls ++ [curr], indent ind str, ind + len) - | otherwise = (ls, curr ++ " " ++ str, width') - where - -- Put it on the next line if it would make the current line too long, - -- AND if it doesn't make the next line too long. - nextLine = width' > maxWidth && ind + len <= maxWidth - len = length str - width' = width + 1 + len + wrap' ss [] = [ss] + wrap' ss (str:strs) + | overflows ss str = + ss : wrapRest maxWidth ind (str:strs) + | otherwise = wrap' (ss ++ " " ++ str) strs + + overflows ss str = length ss > maxWidth || + ((length ss + length str) >= maxWidth && ind + length str <= maxWidth) + + +-------------------------------------------------------------------------------- +wrapRest :: Int + -> Int + -> [String] + -> Lines +wrapRest maxWidth ind = reverse . wrapRest' [] "" + where + wrapRest' ls ss [] + | null ss = ls + | otherwise = ss:ls + wrapRest' ls ss (str:strs) + | null ss = wrapRest' ls (indent ind str) strs + | overflows ss str = wrapRest' (ss:ls) "" (str:strs) + | otherwise = wrapRest' ls (ss ++ " " ++ str) strs + + overflows ss str = (length ss + length str + 1) >= maxWidth -------------------------------------------------------------------------------- @@ -84,12 +112,17 @@ withHead f (x : xs) = f x : xs -------------------------------------------------------------------------------- withLast :: (a -> a) -> [a] -> [a] withLast _ [] = [] -withLast f (x : []) = [f x] +withLast f [x] = [f x] withLast f (x : xs) = x : withLast f xs -------------------------------------------------------------------------------- withInit :: (a -> a) -> [a] -> [a] withInit _ [] = [] -withInit _ (x : []) = [x] +withInit _ [x] = [x] withInit f (x : xs) = f x : withInit f xs + +-------------------------------------------------------------------------------- +withTail :: (a -> a) -> [a] -> [a] +withTail _ [] = [] +withTail f (x : xs) = x : map f xs |