Add hlint config and github action

[philderbeast]

What an awesome addition to the Haskell toolset.

I tried configuring the project for linting and found remarkably few suggestions, all currently ignored. I exclude one module that doesn't parse.

Are you up for enabling -XMultilineStrings? If so I can get HLint to parse that module with this change:

$ git diff
diff --git a/.hlint.yaml b/.hlint.yaml
index 8b68b50..52eea92 100644
--- a/.hlint.yaml
+++ b/.hlint.yaml
@@ -26,5 +26,3 @@
 - ignore: {name: "Use record patterns"} # 1 hint
 - ignore: {name: "Use uncurry"} # 2 hints
 - ignore: {name: "Use unless"} # 2 hints
-- arguments:
-    - --ignore-glob=haskell-debugger/GHC/Debugger/Runtime/Thread/Stack.hs
diff --git a/haskell-debugger/GHC/Debugger/Runtime/Thread/Stack.hs b/haskell-debugger/GHC/Debugger/Runtime/Thread/Stack.hs
index 3eeca85..23441df 100644
--- a/haskell-debugger/GHC/Debugger/Runtime/Thread/Stack.hs
+++ b/haskell-debugger/GHC/Debugger/Runtime/Thread/Stack.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE ViewPatterns #-}
+{-# LANGUAGE MultilineStrings #-}
 
 -- | Decoding the stack of a thread at runtime
 module GHC.Debugger.Runtime.Thread.Stack
@@ -181,10 +182,10 @@ bcoBreakPointInfoParser = do
           | otherwise = 0 :: Int
 
     let find_ixs_fv = Remote.raw $
-          "\\x -> let index_at n = GHC.Word.W16# (GHC.Base.indexWord16Array# x (n GHC.Exts.+# " ++ show bRK_FUN_offset ++ "#)) " ++
-                   "in if (index_at 0# Data.Bits..&. 0xFF) == 66{-bci_BRK_FUN-} then \
-                        Just (index_at 1#, index_at 2#, index_at 3#, index_at 4#, index_at 5#) \
-                      else Nothing"
+          "\\x -> let index_at n = GHC.Word.W16# (GHC.Base.indexWord16Array# x (n GHC.Exts.+# " ++ show bRK_FUN_offset ++ """#))
+                    in if (index_at 0# Data.Bits..&. 0xFF) == 66{-bci_BRK_FUN-} then
+                        Just (index_at 1#, index_at 2#, index_at 3#, index_at 4#, index_at 5#)
+                      else Nothing"""
     rs_fv <- expectRight =<< Remote.eval
       (find_ixs_fv `Remote.app` Remote.untypedRef instrs_array_fv)

[alt-romes]

Hi @philderbeast, welcome! Thanks for taking an interest in the project.

I should say that I'm not particularly inclined to enforce linting on the project.

However, I would be happy to keep the .hlint.yaml file if you think that would make it easier for contributors. I can imagine they would see less unnecessary warnings in their code if it is properly configured, and potentially make it easier to write better code.

Review:

• Using MultiLineStrings sounds good, so we can drop the ad-hoc hlint filter
• As per above, could you drop the CI configuration for linting?

[philderbeast]

I've dropped the github workflow and added -XMultilineStrings in one module.

[alt-romes]

Thanks!

The commit message says

- Ignore Stack.hs with parse error

Could you remove that outdated part? Perhaps say: Add multi-line strings to make hlint capable of parsing that module.

[philderbeast]

I like to leave commit history messages to show how I got to the squashed commit but can rewrite the message to only refer to what can now be seen in the commit.

[alt-romes]

Thanks for updating it! Indeed, in this project we'd rather follow the style where a commit message refers only to what the commit is in the end. Alternative styles are also reasonable, but this is the one we're taking for haskell-debugger.

Thanks again! I'll land it once CI passes.

[philderbeast]

I'm not able to reproduce the "Build and Run Integration Tests (9.14.1)" failure locally, either when setting "DEBUGGER=... make test" in the environment or by doing a cabal install haskell-debugger --overwrite-policy=always before running the test.