chore(users/Profpatsch): bring reverse-haskell-deps into shape

Add a cabal file and move into subdir.
Use MyPrelude & fix a few linter warnings.

Change-Id: I19d5ba47be789fc24f8e02ee8721f73c706ae3e9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8465
Reviewed-by: Profpatsch <mail@profpatsch.de>
Autosubmit: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI

users/Profpatsch/reverse-haskell-deps/ReverseHaskellDeps.hs

@@ -1,72 +1,76 @@
 {-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-import qualified Text.HTML.TagSoup as Tag
-import qualified Data.Text as Text
-import Data.Text (Text)
-import qualified Data.List as List
-import Data.Maybe
-import Text.Nicify
-import qualified Text.Read as Read
-import Numeric.Natural
-import Data.Either
-import qualified Data.ByteString as ByteString
-import qualified Data.Text.Encoding
 
-parseNat :: Text.Text -> Maybe Natural
+module Main where
-parseNat = Read.readMaybe . Text.unpack
+
+import Data.ByteString qualified as ByteString
+import Data.Either
+import Data.List qualified as List
+import Data.Maybe
+import Data.Text (Text)
+import Data.Text qualified as Text
+import Data.Text.Encoding qualified
+import MyPrelude
+import Numeric.Natural
+import Text.HTML.TagSoup qualified as Tag
+import Text.Nicify
+import Text.Read qualified as Read
+
+parseNat :: Text -> Maybe Natural
+parseNat = Read.readMaybe . textToString
 
 printNice :: Show a => a -> IO ()
 printNice = putStrLn . nicify . show
 
-type Tag = Tag.Tag Text.Text
+type Tag = Tag.Tag Text
 
 main = do
   reverseHtml <- readStdinUtf8
   printNice $ List.sortOn snd $ packagesAndReverseDeps reverseHtml
-
   where
-    readStdinUtf8 = Data.Text.Encoding.decodeUtf8 <$> ByteString.getContents
+    readStdinUtf8 = bytesToTextUtf8Lenient <$> ByteString.getContents
 
 -- | reads the table provided by https://packdeps.haskellers.com/reverse
 -- figuring out all sections (starting with the link to the package name),
 -- then figuring out the name of the package and the first column,
 -- which is the number of reverse dependencies of the package
+packagesAndReverseDeps :: Text -> [(Text, Natural)]
 packagesAndReverseDeps reverseHtml = do
   let tags = Tag.parseTags reverseHtml
   let sections = Tag.partitions (isJust . reverseLink) tags
-  let sectionNames = map (fromJust . reverseLink . head) sections
+  let sectionName [] = "<unknown section>"
+      sectionName (sect : _) = sect & reverseLink & fromMaybe "<unknown section>"
+  let sectionNames = map sectionName sections
   mapMaybe
-    (\(name :: Text.Text, sect) -> do
+    ( \(name :: Text, sect) -> do
         reverseDeps <- firstNaturalNumber sect
-        pure (sectionPackageName name sect, reverseDeps) :: Maybe (Text.Text, Natural))
+        pure (sectionPackageName name sect, reverseDeps) :: Maybe (Text, Natural)
+    )
     $ zip sectionNames sections
-
-
   where
     reverseLink = \case
-      Tag.TagOpen "a" attrs -> mapFind attrReverseLink attrs
+      Tag.TagOpen "a" attrs -> findMaybe attrReverseLink attrs
       _ -> Nothing
 
     attrReverseLink = \case
-      ("href", lnk) -> if
+      ("href", lnk) ->
+        if
             | "packdeps.haskellers.com/reverse/" `Text.isInfixOf` lnk -> Just lnk
             | otherwise -> Nothing
       _ -> Nothing
 
     sectionPackageName :: Text -> [Tag] -> Text
     sectionPackageName sectionName = \case
-      (_: Tag.TagText name : _) -> name
+      (_ : Tag.TagText name : _) -> name
-      (_: el : _) -> sectionName
+      (_ : el : _) -> sectionName
       xs -> sectionName
 
-
     firstNaturalNumber :: [Tag] -> Maybe Natural
     firstNaturalNumber =
-      mapFind (\case
+      findMaybe
+        ( \case
             Tag.TagText t -> parseNat t
-        _ -> Nothing)
+            _ -> Nothing
-
+        )
-    mapFind :: (a -> Maybe b) -> [a] -> Maybe b
-    mapFind f xs = fromJust . f <$> List.find (isJust . f) xs

users/Profpatsch/reverse-haskell-deps/default.nix

@@ -19,12 +19,13 @@ let
   rev-hs = pkgs.writers.writeHaskell "revers-haskell-deps-hs"
     {
       libraries = [
+        depot.users.Profpatsch.my-prelude
         pkgs.haskellPackages.nicify-lib
         pkgs.haskellPackages.tagsoup
       ];
 
     }
-    ./reverse-haskell-deps.hs;
+    ./ReverseHaskellDeps.hs;
 
 
 in

users/Profpatsch/reverse-haskell-deps/reverse-haskell-deps.cabal

@@ -0,0 +1,16 @@
+cabal-version:      2.4
+name:               reverse-haskell-deps
+version:            0.1.0.0
+author:             Profpatsch
+maintainer:         mail@profpatsch.de
+
+library
+    exposed-modules:          ReverseHaskellDeps.hs
+
+    build-depends:
+        base >=4.15 && <5,
+        my-prelude,
+        tagsoup,
+        nicify-lib
+
+    default-language: Haskell2010

users/Profpatsch/shell.nix

@@ -29,6 +29,7 @@ pkgs.mkShell {
       h.nonempty-containers
       h.deriving-compat
       h.unix
+      h.tagsoup
       h.attoparsec
       h.iCalendar
       h.case-insensitive