switch to universum prelude

also don't keep adjusted maps around if not necessary

1 files changed, 15 insertions, 16 deletions

diff --git a/lib/Paths.hs b/lib/Paths.hs
index 15dc66b..f4dc3ed 100644
--- a/lib/Paths.hs
+++ b/lib/Paths.hs
@@ -7,15 +7,16 @@
 -- I just hope you are running this on some kind of Unix
 module Paths where
 
-import           Control.DeepSeq       (NFData)
-import           Data.Text             (Text, isPrefixOf)
+import           Universum
+import qualified Universum.Unsafe      as Unsafe
+
 import qualified Data.Text             as T
-import           GHC.Generics          (Generic)
 import           System.FilePath       (splitPath)
 import           System.FilePath.Posix ((</>))
 import           Text.Regex.TDFA
 import           Util                  (PrettyPrint (prettyprint))
 
+
 -- | a normalised path: a number of "upwards" steps, and
 -- a path without any . or .. in it. Also possibly a
 -- fragment, mostly for map links.
@@ -36,9 +37,9 @@ parsePath :: Text -> PathResult
 parsePath text =
   if | T.isInfixOf "{{" text || T.isInfixOf "}}" text -> PathVarsDisallowed
      | rest =~ ("^([^/]*[^\\./]/)*[^/]*[^\\./]$" :: Text) -> OkRelPath (Path up path fragment)
-     | "/_/" `isPrefixOf` text ->  UnderscoreMapLink
-     | "/@/" `isPrefixOf` text ->  AtMapLink
-     | "/" `isPrefixOf` text ->  AbsolutePath
+     | "/_/" `T.isPrefixOf` text ->  UnderscoreMapLink
+     | "/@/" `T.isPrefixOf` text ->  AtMapLink
+     | "/" `T.isPrefixOf` text ->  AbsolutePath
      | otherwise ->  NotAPath
   where
     (_, prefix, rest, _) =
@@ -47,10 +48,10 @@ parsePath text =
     up = length . filter (".." ==) . T.splitOn  "/" $ prefix
     parts = T.splitOn "#" rest
     -- `head` is unsafe, but splitOn will always produce lists with at least one element
-    path = head parts
-    fragment = if length parts >= 2
-      then Just $ T.concat $ tail parts
-      else Nothing
+    path = Unsafe.head parts
+    fragment = case nonEmpty parts of
+      Nothing -> Nothing
+      Just p  -> Just $ T.concat $ tail p
 
 instance PrettyPrint RelPath where
   prettyprint (Path up rest frag) = ups <> rest <> fragment
@@ -63,14 +64,14 @@ instance PrettyPrint RelPath where
 -- at the end of the prefix, i.e. it will never return paths
 -- that lie (naïvely) outside of the prefix.
 normalise :: FilePath -> RelPath ->  FilePath
-normalise prefix (Path 0 path _) = prefix </> T.unpack path
+normalise prefix (Path 0 path _) = prefix </> toString path
 normalise prefix (Path i path _) =
-  concat (take (length dirs - i) dirs) </> T.unpack path
+  concat (take (length dirs - i) dirs) </> toString path
   where dirs = splitPath prefix
 
 normaliseWithFrag :: FilePath -> RelPath -> FilePath
 normaliseWithFrag prefix (Path i path frag) =
-  normalise prefix (Path (i+1) path frag) <> T.unpack (maybe mempty ("#" <>) frag)
+  normalise prefix (Path (i+1) path frag) <> toString (maybe mempty ("#" <>) frag)
 
 -- | does this path contain an old-style pattern for inter-repository
 -- links as was used at rc3 in 2020?
@@ -81,7 +82,5 @@ isOldStyle (Path _ text frag) = path =~ ("{<.+>*}" :: Text)
           _      -> text
 
 getExtension :: RelPath -> Text
-getExtension (Path _ text _) = case length splitted of
-  0 -> ""
-  _ -> last splitted
+getExtension (Path _ text _) = maybe "" last (nonEmpty splitted)
   where splitted = T.splitOn "." text