Attempt to update packaging (#54)

This pull request updates the `pkg-darwin` recipe.

This pull request also attempts to provide a better way to provision a
Haskell package environment, but ends up documenting the current lack of
success with GHC [package environments][package-env] instead.

[package-env]:
https://ghc.gitlab.haskell.org/ghc/doc/users_guide/packages.html#package-environments

Author: HeinrichApfelmus

.gitignore

@@ -10,3 +10,4 @@ dist-newstyle/
 *.sublime-workspace
 node_modules
 /build
+/haskell/vendor/

app/package.json

@@ -1,6 +1,6 @@
 {
   "name": "HyperHaskell",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "main": "src/main.js",
   "devDependencies": {
     "electron": "^31.4.0"

app/src/interpreter.js

@@ -137,8 +137,10 @@ exports.init = () => {
     })
     ghc.on('exit', (code, signal) => {
       // FIXME: Report a more useful error here.
-      // Unfortunatley, we can't read `stderr` once the process is dead.
+      // Unfortuntaley, we can't read `stderr` once the process is dead.
       // Perhaps cache it in some way?
+      // Idea: The interpreter executable can print the error to
+      // the pipeFD descriptor, as opposed to stdout
       error = code ? code.toString() : '0';
       console.log('Interpreter stopped (Exit code ' + error + ')')
       if (spawning) { doReady(error) }

docs/misc.md

@@ -1,24 +1,10 @@
 Misc
-=====
-
-This documentation collects useful miscellanea.
-
-Testing POST requests
----------------------
+====
 
-The `curl` utility is able to send POST requests and receive a response. Example:
-
-    $ curl --data "query=Prelude" http://localhost:8024/setImports
-    {"status":"ok"}
-    $ curl --data "query=3*4::Int" http://localhost:8024/eval
-    {"status":"ok","value":"12"}
-
-Note that `curl` will not, by default, add a newline to the end of the received request; this may screw up the terminal. However, the option `-w '\n'` will add said newline. To make it a default, use the `~/.curlrc` file [[StackOverflow]][12849584].
-
-    echo '-w "\n"' >> ~/.curlrc
-
-  [12849584]: http://stackoverflow.com/questions/12849584/automatically-add-newline-at-end-of-curl-response-body
+This document records snippets of information that are useful for developing HyperHaskell.
 
+Haskell
+=======
 
 How does GHCi evaluate expressions on the prompt?
 -------------------------------------------------
@@ -72,17 +58,6 @@ Fortunately, a Google search reveals that the relevant code is actually containe
 In other words, GHC tries to typecheck the expression at the prompt in different contexts, and uses the first plan that works.
 
 
-How to create an .icns file on OS X?
-------------------------------------
-
-Application icons on OS X are stored in `.icns` files. There is a command line utility called `iconutil` that is supposed to be able to create such files, but unfortunately, it only creates garbled icons for me. No idea why. Online converters seem to work fine.
-
-How to remove color profiles from images on OS X?
--------------------------------------------------
-
-    sips -d profile --deleteColorManagementProperties *filename*
-
-
 Haskell path information
 ------------------------
 
@@ -122,8 +97,10 @@ For my setup, a minimal environment is given by
         HOME=/Users/hgz \
         stack exec -- hyper-haskell-server
 
+JavaScript
+==========
 
-Node.js -- External Processes
+Node.js — External Processes
 -----------------------------
 
 We can run external processes and read their `stdout`. Example:
@@ -135,4 +112,76 @@ We can run external processes and read their `stdout`. Example:
         env : newEnv(),
       }).stdout.trim()
 
-Note that most UNIX utilities will traditionally emit a newline at the end of the output, and we use `trim()` to get rid of it.
+Note that most UNIX utilities will traditionally emit a newline at the end of the output, and we use `trim()` to get rid of it.
+
+
+Cabal and GHC package environments
+----------------------------------
+
+A working installation of the HyperHaskell interpreter backend consists of two things:
+
+1. The interpreter executable `hyper-haskell-server`, linked against a compilation A of the `hyper` package.
+2. A package database that contains this compilation A of the `hyper` package. This database needs to be in scope when running the interpreter excutable.
+
+How to provision these?
+
+As of December 2024, it seemed like GHC [package environments][package-env] might be useful to provision the above setup, but unfortunately, this does not work.
+
+The following command will install the package `hyper` into the package environment `PKG_ENV`:
+
+```
+cabal install --lib hyper --package-env ${PKG_ENV}
+```
+
+The following command will install `hyper-haskell-server` into the directory `DIR` while referring to packages from the package environment `PKG_ENV`:
+
+```
+cabal install hyper-haskell-server --package-env ${PKG_ENV} --installdir=${DIR}
+```
+
+By using the same package environment `PKG_ENV`, we make sure that both the interpreter exectuable and the package environment refer to the same compilation of the `hyper` package.
+
+Unfortunately, the two commands above do not produce a working setup: `cabal install --lib` does [not install dependencies][cabal-issue-6263], and the GHC API as used by `hyper-haskell-server` is unable to handle that; I get error messages of the form
+
+```
+cannot satisfy -package-id hypr-xtr-0.2.0.1-71ddd09d: 
+    hypr-xtr-0.2.0.1-71ddd09d is unusable due to missing dependencies:
+[…]
+```
+
+(The "missing dependency" appears to be present in the package database, and `ghci` is able to handle the situation, but the use of the GHC API by `hyper-haskell-server` is not.)
+
+To summarize, as of December 2024, I can't get GHC package environments to yield a working installation of the HyperHaskell interpreter backend.
+
+  [package-env]: https://ghc.gitlab.haskell.org/ghc/doc/users_guide/packages.html#package-environments
+  [cabal-issue-6263]: https://github.com/haskell/cabal/issues/6263
+
+
+Tools
+=====
+
+Testing POST requests
+---------------------
+
+The `curl` utility is able to send POST requests and receive a response. Example:
+
+    $ curl --data "query=Prelude" http://localhost:8024/setImports
+    {"status":"ok"}
+    $ curl --data "query=3*4::Int" http://localhost:8024/eval
+    {"status":"ok","value":"12"}
+
+Note that `curl` will not, by default, add a newline to the end of the received request; this may screw up the terminal. However, the option `-w '\n'` will add said newline. To make it a default, use the `~/.curlrc` file [[StackOverflow]][12849584].
+
+    echo '-w "\n"' >> ~/.curlrc
+
+  [12849584]: http://stackoverflow.com/questions/12849584/automatically-add-newline-at-end-of-curl-response-body
+
+How to create an .icns file on OS X?
+------------------------------------
+
+Application icons on OS X are stored in `.icns` files. There is a command line utility called `iconutil` that is supposed to be able to create such files, but unfortunately, it only creates garbled icons for me. No idea why. Online converters seem to work fine.
+
+How to remove color profiles from images on OS X?
+-------------------------------------------------
+
+    sips -d profile --deleteColorManagementProperties *filename*

flake.nix

@@ -41,6 +41,7 @@
             pkgs.pkg-config
             pkgs.zlib
 
+            pkgs.nodejs_22
             pkgs.electron
           ] ++ lib.optionals pkgs.stdenv.isDarwin ([
             pkgs.darwin.apple_sdk.frameworks.Cocoa

haskell/hyper-haskell-server/src/HyperHaskell/Interpreter.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE GADTSyntax #-}
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 module HyperHaskell.Interpreter
     ( -- * Interpreter session
@@ -299,6 +300,11 @@ newInterpreter writeReady = do
             putMVar evalThreadId =<< myThreadId
             -- NOTE: The failure branch of `catch` will `mask` asynchronous exceptions.
             let go = forever $ handler `catch` (\UserInterrupt -> pure ())
-            void $ Hint.runInterpreter $ liftIO writeReady >> go
+            (e :: Either Hint.InterpreterError ()) <- Hint.runInterpreter $ do
+                liftIO writeReady
+                go
+            case e of
+                Left e' -> print e'
+                Right _ -> pure ()
 
     pure (Hint run cancel, interpreterLoop)

justfile

@@ -1,7 +1,5 @@
 ELECTRON := "electron"
 
-STACK := "stack --stack-yaml=haskell/stack.yaml --install-ghc"
-
 VERSION := "0.2.3.0"
 
 ######################################################################
@@ -22,14 +20,27 @@ build:
 ######################################################################
 # Release targets
 
-DIR_DARWIN := "build/HyperHaskell-darwin-x64"
-DIR_WIN32 := "build\\HyperHaskell-win32-x64"
+APP_NAME := "HyperHaskell"
+
+DIR_DARWIN := "build/" + APP_NAME + "-darwin-arm64"
+DIR_WIN32 := "build\\" + APP_NAME + "-win32-x64"
 
+# You need to call
+#
+#   npm install --save-dev @electron/packager
+#   npm install electron --save-dev
+#
+# before the following recipe has a chance of working
 pkg-darwin:
-	mkdir -p build && electron-packager app \
-		--out=build/ --overwrite \
-		--platform=darwin --icon=resources/icons/icon.icns \
-		--extend-info=resources/macOS-Info.plist \
+	mkdir -p build \
+		&& npx @electron/packager \
+			app \
+			--out=build \
+			--overwrite \
+			--platform=darwin \
+			--arch=arm64 \
+			--icon=resources/icons/icon.icns \
+			--extend-info=resources/macOS-Info.plist \
 		&& rm {{DIR_DARWIN}}/LICENSE \
 		&& cp resources/LICENSE.electron.txt {{DIR_DARWIN}}/LICENSE.electron.txt \
 		&& rm {{DIR_DARWIN}}/version