merge: pull request #5337 from iyefrat/haskell

Improve `:lang haskell`

core/core-modules.el

@@ -172,7 +172,7 @@ following properties:
   :path  [STRING]       path to category root directory
 
 Example:
-  (doom-module-set :lang 'haskell :flags '(+dante))"
+  (doom-module-set :lang 'haskell :flags '(+lsp))"
   (puthash (cons category module) plist doom-modules))
 
 (defun doom-module-path (category module &optional file)

docs/modules.org

@@ -117,7 +117,7 @@ Modules that bring support for a language or group of languages to Emacs.
 + [[file:../modules/lang/fstar/README.org][fstar]] - F* support
 + [[file:../modules/lang/gdscript/README.org][gdscript]] =+lsp= - TODO
 + [[file:../modules/lang/go/README.org][go]] =+lsp= - TODO
-+ [[file:../modules/lang/haskell/README.org][haskell]] =+dante +ghcide +lsp= - TODO
++ [[file:../modules/lang/haskell/README.org][haskell]] =+lsp= - TODO
 + hy - TODO
 + [[file:../modules/lang/idris/README.org][idris]] - TODO
 + java =+meghanada +eclim +lsp= - TODO

init.example.el

@@ -132,7 +132,7 @@
        ;;fstar             ; (dependent) types and (monadic) effects and Z3
        ;;gdscript          ; the language you waited for
        ;;(go +lsp)         ; the hipster dialect
-       ;;(haskell +dante)  ; a language that's lazier than I am
+       ;;(haskell +lsp)    ; a language that's lazier than I am
        ;;hy                ; readability of scheme w/ speed of python
        ;;idris             ; a language you can depend on
        ;;json              ; At least it ain't XML

modules/lang/haskell/+dante.el

@@ -1,41 +0,0 @@
-;;; lang/haskell/+dante.el -*- lexical-binding: t; -*-
-;;;###if (featurep! +dante)
-
-(use-package! dante
-  :hook (haskell-mode-local-vars . dante-mode)
-  :init
-  (setq dante-load-flags '(;; defaults:
-                           "+c"
-                           "-Wwarn=missing-home-modules"
-                           "-fno-diagnostics-show-caret"
-                           ;; necessary to make attrap-attrap useful:
-                           "-Wall"
-                           ;; necessary to make company completion useful:
-                           "-fdefer-typed-holes"
-                           "-fdefer-type-errors"))
-  :config
-  (when (featurep! :checkers syntax)
-    (flycheck-add-next-checker 'haskell-dante '(warning . haskell-hlint)))
-
-  (set-company-backend! 'dante-mode #'dante-company)
-
-  (defadvice! +haskell--restore-modified-state-a (fn &rest args)
-    "Marks the buffer as falsely modified.
-Dante quietly saves the current buffer (without triggering save hooks) before
-invoking flycheck, unexpectedly leaving the buffer in an unmodified state. This
-is annoying if we depend on save hooks to do work on the buffer (like
-reformatting)."
-    :around #'dante-async-load-current-buffer
-    (let ((modified-p (buffer-modified-p)))
-      (apply fn args)
-      (if modified-p (set-buffer-modified-p t))))
-
-  (when (featurep 'evil)
-    (add-hook 'dante-mode-hook #'evil-normalize-keymaps))
-  (map! :map dante-mode-map
-        :localleader
-        "t" #'dante-type-at
-        "i" #'dante-info
-        "l" #'haskell-process-load-file
-        "e" #'dante-eval-block
-        "a" #'attrap-attrap))

modules/lang/haskell/+lsp.el

@@ -1,11 +0,0 @@
-;;; lang/haskell/+lsp.el -*- lexical-binding: t; -*-
-
-(use-package! lsp-haskell
-  :after lsp-mode
-  :preface (add-hook 'haskell-mode-local-vars-hook #'lsp!)
-  :config
-  (when (featurep! +ghcide)
-    (setq lsp-haskell-server-path "ghcide"
-          lsp-haskell-server-args nil))
-  ;; Does some strange indentation if it pastes in the snippet
-  (setq-hook! 'haskell-mode-hook yas-indent-line 'fixed))

modules/lang/haskell/README.org

@@ -5,152 +5,69 @@
 
 * Table of Contents :TOC:
 - [[#description][Description]]
-  - [[#external-resources][External resources]]
+  - [[#maintainers][Maintainers]]
   - [[#module-flags][Module Flags]]
   - [[#plugins][Plugins]]
 - [[#prerequisites][Prerequisites]]
-  - [[#cabal][Cabal]]
+- [[#features][Features]]
-  - [[#lsp-haskell-language-server][LSP (haskell-language-server)]]
-  - [[#lsp-ghcide][LSP (ghcide)]]
-  - [[#stack][Stack]]
-  - [[#haskell-packages][Haskell packages]]
 - [[#configuration][Configuration]]
-  - [[#using-the-new-style-cabal-repl][Using the new-style cabal REPL]]
-- [[#troubleshooting][Troubleshooting]]
 
 * Description
-This module adds [[https://www.haskell.org/][Haskell]] support, powered by either [[https://github.com/jyp/dante][dante]] (the default) or LSP
+Adds Haskell support to Doom Emacs.
-(haskell-language-server or ghcide).
 
-+ Code completion (~company-ghc~)
+** Maintainers
-+ Look up documentation (~hoogle~)
+This module has no dedicated maintainers.
-+ eldoc support (~dante~)
-+ REPL (~ghci~)
-+ Syntax-checking (~flycheck~)
-+ Code navigation (~dante~)
-+ [[https://github.com/hlissner/doom-snippets/tree/master/haskell-mode][Snippets]]
-
-** External resources
-Here are a few resources I've found indispensable in my Haskell adventures:
-
-+ [[http://learnyouahaskell.com/][Learn you a haskell for great good]]
-+ [[http://haskellbook.com/][Haskell Programming from first principles]]
-+ [[https://github.com/krispo/awesome-haskell][Awesome Haskell]]: an extensive list of haskell resources
-+ [[https://docs.haskellstack.org/en/stable/README/][The Haskell Tool Stack docs]]
 
 ** Module Flags
-+ =+dante= Enables dante; a fork of intero aimed at lightweightedness. It
++ =+lsp= Enable LSP support with for [[https://github.com/haskell/haskell-language-server][haskell-language-server]] (requires the =:tools lsp= module).
-  doesn't depend on =stack=, supports both ~cabal~-only and ~stack~ projects,
-  but lacks eldoc support.
-+ =+ghcide= Enables LSP support with ghcide (requires the ~:tools lsp~ module).
-+ =+lsp= Enables LSP support with haskell-language-server (requires the ~:tools lsp~
-  module).
 
 ** Plugins
 + [[https://github.com/haskell/haskell-mode][haskell-mode]]
-+ =+dante=
++ [[https://github.com/emacs-lsp/lsp-haskell][lsp-haskell]] (=+lsp=, =:tools lsp=)
-  + [[https://github.com/jyp/dante][dante]]
-  + [[https://github.com/jyp/attrap][attrap]]
-+ =+lsp=
-  + [[https://github.com/emacs-lsp/lsp-haskell][lsp-haskell]]
 
 * Prerequisites
-Depending on whether you use Dante, haskell-language-server or ghcide, your
+It is recommended to install the haskell tooling using [[https://www.haskell.org/ghcup/][ghcup]]. Only ghc is needed
-dependencies will differ:
+for basic functionality:
 
-+ Dante users need =cabal=, =ghc= and =ghc-mod=
+#+BEGIN_SRC bash
-+ LSP users need the =haskell-language-server= LSP server OR =ghcide=
+ghcup install ghc
-+ All users will need the =hoogle= package
-
-** Cabal
-To use Dante, you need =cabal= (the haskell package builder) and =ghci= (the
-compiler, syntax checker & repl):
-
-*** MacOS
-#+BEGIN_SRC sh
-brew install cabal-install ghc
 #+END_SRC
 
-*** Arch Linux
+but =+lsp= users should also install the language server:
-#+BEGIN_SRC sh
-sudo pacman -S cabal-install ghc
-#+END_SRC
-
-*** openSUSE
-#+BEGIN_SRC sh :dir /sudo::
-sudo zypper install cabal-install ghc
-#+END_SRC
-
-** LSP (haskell-language-server)
-You will need =stack= and =git= installed.
-
-You will find a comprehensive [[https://github.com/haskell/haskell-language-server#installation][instructions for haskell-language-server on its project page]], but if you are using [[https://www.haskell.org/ghcup/][ghcup]]:
 
 #+BEGIN_SRC bash
 ghcup install hls
 #+END_SRC
 
-** LSP (ghcide)
+Installing [[https://www.haskell.org/cabal/][cabal]] or [[https://docs.haskellstack.org/en/stable/README/][stack]] as well is recommended, and can be done through
-See https://github.com/digital-asset/ghcide for install instructions.
+=ghcup=.
 
-** Stack
+=haskell-mode= provides support for [[https://github.com/ndmitchell/hoogle][hoogle]], which can be installed through
-To use LSP, you need =stack=:
+system package manager, cabal, or stack.
 
-*** MacOS
+=haskell-language-server= provides support for [[https://github.com/ndmitchell/hlint/][hlint]], and haskell code
-#+BEGIN_SRC sh
+formatters such as [[https://github.com/lspitzner/brittany][brittany]], [[https://github.com/ennocramer/floskell][floskell]], [[https://github.com/tweag/ormolu][ormolu]], [[https://github.com/fourmolu/fourmolu][fourmolu]], and [[https://github.com/haskell/stylish-haskell][stylish-haskell]],
-brew install haskell-stack
+which can be installed through system package manager, cabal, or stack.
-stack setup
-#+END_SRC
-*** Arch Linux
-#+BEGIN_SRC sh
-sudo pacman -S stack
-# Replace pacaur with your AUR package manager of choice
-pacaur -S ncurses5-compat-lib
-stack setup
-#+END_SRC
 
-*** openSUSE
+* Features
-#+BEGIN_SRC sh :dir /sudo::
+This module intergrates the haskell packages into Doom by providing things such
-sudo zypper install stack
+as repl support, project root recognition, etc. It also provide the following
-stack setup
+keybindings:
-#+END_SRC
 
-** Haskell packages
+| Keybinding        | Description                                   |
-You'll need to install the following packages using ~stack~ or ~cabal~:
+|-------------------+-----------------------------------------------|
-
+| =<localleader> b= | Build the current cabal project               |
-+ (Dante users) =ghc-mod=
+| =<localleader> c= | Visit the =.cabal= file of the current buffer |
-  #+BEGIN_SRC sh
+| =<localleader> h= | Toggle visibility of the form at point        |
-  stack install ghc-mod
+| =<localleader> H= | hides all top level functions                 |
-  # or
-  cabal install ghc-mod
-  #+END_SRC
-+ =hoogle=
-  #+BEGIN_SRC sh
-  cabal update
-  cabal install happy haskell-src-exts   # ghc-mod/hoogle dependencies
-  cabal ghc-mod hoogle
-  # or
-  stack install ghc-mod
-  stack install hoogle
-  #+END_SRC
-
-And ensure the binaries for these packages are in your ~PATH~, e.g.
-
-#+BEGIN_SRC sh
-# place this in your profile file, like ~/.bash_profile or ~/.zshenv
-export PATH="~/.local/bin:$PATH"
-#+END_SRC
 
 * Configuration
-** Using the new-style cabal REPL
+After installing your preferred formatter, make sure to set
-=haskell-mode= will typically detect what REPL to run based on your project
+=lsp-haskell-formatting-provider= to it.
-(e.g. stack, (old-style) cabal or ghc). If you want the new-style cabal REPL you
-must set ~haskell-process-type~ manually:
 
-#+BEGIN_SRC emacs-lisp
+Make sure to configure the lsp to use your perfered formatter, e.g.:
-(setq haskell-process-type 'cabal-new-repl)
+#+BEGIN_SRC elisp
+;; ~/.doom.d/config.el
+(after!
+  (setq lsp-haskell-formatting-provider "brittany"))
 #+END_SRC
-
-* Troubleshooting
-+ Stack users: a ~dist/setup-config~ file in your project may cause [[https://github.com/DanielG/ghc-mod/wiki#known-issues-related-to-stack][ghc-mod to
-  not work]].

modules/lang/haskell/config.el

@@ -43,10 +43,10 @@
         "H" #'haskell-hide-toggle-all))
 
 
-;;
+(use-package! lsp-haskell
-;;; Backends
+  :when (featurep! +lsp)
-
+  :after lsp-mode
-(cond ((featurep! +dante)  (load! "+dante"))
+  :preface (add-hook 'haskell-mode-local-vars-hook #'lsp!)
-      ((or (featurep! +lsp)
+  :config
-           (featurep! +ghcide))
+  ;; Does some strange indentation if it pastes in the snippet
-       (load! "+lsp")))
+  (setq-hook! 'haskell-mode-hook yas-indent-line 'fixed))

modules/lang/haskell/doctor.el

@@ -5,8 +5,22 @@
              (featurep! :tools lsp))
          "This module requires (:tools lsp)")
 
-(when (featurep! +dante)
+(unless (executable-find "cabal")
-  (unless (executable-find "cabal")
+  (warn! "Couldn't find cabal. haskell-mode may have issues."))
-    (warn! "Couldn't find cabal, haskell-mode may have issues"))
+
-  (unless (executable-find "hlint")
+(unless (executable-find "hoogle")
-    (warn! "Couldn't find hlint. Flycheck may have issues in haskell-mode")))
+  (warn! "Couldn't find hoogle. Documentation searching will not work."))
+
+(unless (or (featurep! +lsp)
+            (executable-find "hlint"))
+  (warn! "Couldn't find hlint. Flycheck may have issues in haskell-mode.
+  Install it or enable +lsp."))
+
+(when (and (featurep! :editor format)
+           (not (executable-find "brittany")))
+      (warn! "Couldn't find brittany. Code formatting will not work.
+  Install it or enable +lsp."))
+
+(when (and (featurep! +lsp)
+           (not (executable-find "haskell-language-server-wrapper")))
+  (warn! "Couldn't find haskell-language-server."))

modules/lang/haskell/packages.el

@@ -3,10 +3,6 @@
 
 (package! haskell-mode :pin "98ba3922360199d5260d47f417f096730ad057c5")
 
-(when (featurep! +dante)
+(when (and (featurep! +lsp)
-  (package! dante :pin "8741419333fb85ed2c1d71f5902688f5201b0a40")
-  (package! attrap :pin "a5bc695af27349ae6fe4541a581e6fd449d2a026"))
-(when (or (and (featurep! +lsp)
            (not (featurep! :tools lsp +eglot)))
-          (featurep! +ghcide))
   (package! lsp-haskell :pin "4e62cf897dd9e9fcef25c6e8e483490a07a5d439"))