feat(emacs): Haskell

users/crumb/programs/emacs/modules/lang/syd-lang-clojure.el

@@ -51,11 +51,13 @@
       #'cider-eval-region))
   :custom ((cider-show-error-buffer nil))
   :general
+  ;; DEPRECATED: Remove once a `map!' equivalent is implemented.
   (:keymaps 'cider-repl-mode-map
    :states '(normal insert)
    "C-k" #'cider-repl-backward-input
    "C-j" #'cider-repl-forward-input
    "C-s" #'cider-repl-previous-matching-input)
+  ;; DEPRECATED: Remove once a `map!' equivalent is implemented.
   (:keymaps 'clojure-mode-map
    :states '(normal visual motion emacs insert)
    :major-modes t

users/crumb/programs/emacs/modules/lang/syd-lang-haskell.el

@@ -0,0 +1,69 @@
+;;; syd-lang-haskell.el -*- lexical-binding: t; -*-
+
+(require 'syd-handle-repl)
+(require 'syd-handle-lookup)
+
+(defun syd-haskell-open-repl ()
+  "Open a Haskell REPL."
+  (interactive)
+  (require 'inf-haskell)
+  (run-haskell))
+
+(defun syd-haskell-evil-open-above ()
+  "Opens a line above the current, following Haskell-mode's indentation"
+  (interactive)
+  (evil-beginning-of-line)
+  (haskell-indentation-newline-and-indent)
+  (evil-previous-line)
+  (haskell-indentation-indent-line)
+  (evil-append-line nil))
+
+(defun syd-haskell-evil-open-below ()
+  "Opens a line below the current, following Haskell-mode's indentation"
+  (interactive)
+  (evil-append-line nil)
+  (haskell-indentation-newline-and-indent))
+
+(use-package haskell-mode
+  :mode (("\\.l?hs'" . haskell-literate-mode)
+         ("\\.hs'" . haskell-mode))
+  :custom (; Show errors in REPL, not popup buffers.
+           (haskell-interactive-popup-errors nil)
+           (haskell-process-suggest-remove-import-line t)
+           (haskell-process-auto-import-loaded-modules t))
+  :general
+  ;; DEPRECATED: Remove once a `map!' equivalent is implemented.
+  (:keymaps 'haskell-mode-map
+   :states '(normal visual motion emacs insert)
+   :major-modes t
+   :prefix syd-localleader-key
+   :non-normal-prefix syd-alt-localleader-key
+   "c" #'haskell-cabal-visit-file
+   "h s" #'haskell-hoogle-start-server
+   "h q" #'haskell-hoogle-kill-server)
+  (general-def :keymaps 'interactive-haskell-mode-map
+   :states '(normal insert)
+   "C-j" #'haskell-interactive-mode-history-next
+   "C-k" #'haskell-interactive-mode-history-previous)
+  :config
+  (set-repl-handler! '(haskell-mode haskell-cabal-mode literate-haskell-mode)
+    #'syd-haskell-open-repl
+    ;; Haskell-mode provides IDE features by communicating with a persistent
+    ;; REPL process à la Lisp.
+    :persist t)
+  (add-to-list 'completion-ignored-extensions ".hi")
+  
+  ;; Don't kill REPL popup on ESC/C-g
+  (set-popup-rule! "^\\*haskell\\*" :quit nil)
+  (syd-add-hook 'haskell-mode-local-vars-hook
+    ;; Folding of Haskell sections.
+    #'haskell-collapse-mode
+    #'interactive-haskell-mode))
+
+(use-package lsp-haskell
+  :defer t
+  :init
+  (add-hook 'haskell-mode-local-vars-hook #'lsp 'append)
+  (add-hook 'haskell-literate-mode-local-vars-hook #'lsp 'append))
+
+(provide 'syd-lang-haskell)

users/crumb/programs/emacs/modules/syd-lang.el

@@ -4,5 +4,6 @@
 (require 'syd-lang-emacs-lisp)
 (require 'syd-lang-clojure)
 (require 'syd-lang-nix)
+(require 'syd-lang-haskell)
 
 (provide 'syd-lang)

users/crumb/programs/emacs/modules/syd-projects.el

@@ -79,6 +79,9 @@
       ;; REVIEW: Is it safe to make this be async?  We require that the command
       ;; has finished before Git initialises.
       (skeletor-shell-command "nix run github:jlesquembre/clj-nix#deps-lock"
-                              dir))))
+                              dir)))
+  (skeletor-define-template "haskell-flake"
+    :title "Haskell (Flake)"
+    :license-file-name "LICENSE"))
 
 (provide 'syd-projects)

users/crumb/programs/emacs/modules/syd-tooling.el

@@ -1,5 +1,17 @@
 ;;; syd-tooling.el -*- lexical-binding: t; -*-
 
+(defun syd-lsp-lookup-documentation ()
+  (interactive)
+  (when-let* ((buf (get-buffer "*lsp-help*")))
+    (kill-buffer buf))
+  (call-interactively #'lsp-describe-thing-at-point)
+  (let ((buf (get-buffer "*lsp-help*")))
+    (when (get-buffer-window-list buf)
+      ;; Bury the buffer so the popup system has full control over how it's
+      ;; selected.
+      (bury-buffer buf)
+      buf)))
+
 (use-package lsp-mode
   :init
   ;; We'll bind things ourselves.
@@ -25,7 +37,13 @@
     (user-error (concat "Ignoring a call to `lsp-install-server'"
                         " — tell the caller to use Nix!")))
   (set-popup-rule! (rx line-start "*lsp-" (or "help" "install"))
-    :size 0.35 :quit t :select nil))
+    :size 13 :quit t :select nil)
+
+  ;; DEPRECATED: Remove once syd-strategies is working.
+  (syd-add-hook 'lsp-mode
+    (defun syd-lsp-set-handlers-h ()
+      (setq-local syd-lookup-documentation-handlers
+                  (list #'syd-lsp-lookup-documentation)))))
 
 (use-package envrc
   ;; REVIEW: Can we load this any later/better?

users/crumb/programs/emacs/project-skeletons/haskell-flake/.envrc

@@ -0,0 +1 @@
+use flake

users/crumb/programs/emacs/project-skeletons/haskell-flake/__PROJECT-NAME__.cabal

@@ -0,0 +1,63 @@
+cabal-version:   3.0
+name:            __PROJECT-NAME__
+version:         0.1.0.0
+synopsis:        __DESCRIPTION__
+description:     __DESCRIPTION__
+license:         GPL-3.0-only
+license-file:    LICENSE
+author:          __USER-NAME__
+maintainer:      __USER-MAIL-ADDRESS__
+
+-- copyright:
+category:        Language
+build-type:      Simple
+extra-doc-files:
+
+common common
+  ghc-options: -Wno-typed-holes -fdefer-typed-holes
+
+  default-extensions:
+    BlockArguments
+    DataKinds
+    DeriveDataTypeable
+    DeriveGeneric
+    DeriveTraversable
+    DerivingVia
+    FlexibleContexts
+    GADTs
+    GeneralisedNewtypeDeriving
+    LambdaCase
+    MultiWayIf
+    NoFieldSelectors
+    OverloadedLabels
+    OverloadedRecordDot
+    OverloadedStrings
+    PartialTypeSignatures
+    PatternSynonyms
+    StandaloneDeriving
+    TypeApplications
+    TypeFamilies
+
+  default-language:   GHC2021
+
+library
+  import: common
+
+  -- cabal-fmt: expand sydml/src/ -Main
+  exposed-modules:
+
+  default-language: GHC2021
+
+  build-depends:
+    , base                       ^>=4.19.1.0
+    , containers
+    , hashable
+    , mtl
+    , lens
+    , pretty-simple
+    , text                       >=2.0       && <2.2
+    , transformers
+    , unordered-containers
+
+  hs-source-dirs: src
+

users/crumb/programs/emacs/project-skeletons/haskell-flake/flake.nix

@@ -0,0 +1,36 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, ... }@inputs:
+    inputs.flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        hlib = pkgs.haskell.lib.compose;
+        hpkgs = pkgs.haskell.packages.ghc98.extend (final: prev: {
+          __PROJECT-NAME__ =
+            hlib.dontCheck (final.callCabal2nix "__PROJECT-NAME__" ./. {});
+        });
+      in {
+        packages = rec {
+          __PROJECT-NAME__ = hpkgs.__PROJECT-NAME__;
+          default = __PROJECT-NAME__;
+        };
+
+        devShells.default = hpkgs.shellFor {
+          packages = p: [
+            p.__PROJECT-NAME__
+          ];
+          nativeBuildInputs = [
+            hpkgs.cabal-fmt
+            hpkgs.fourmolu
+            hpkgs.haskell-language-server
+            hpkgs.cabal-install
+            hpkgs.hasktags
+          ];
+          withHoogle = true;
+        };
+      });
+}

users/crumb/programs/git.nix

@@ -1,6 +1,7 @@
 { config, lib, pkgs, ... }:
 
 let
+  # TODO: Move somewhere else.
   my-email = "lomiskiam@gmail.com";
   my-name = "Madeleine Sydney";
 in lib.mkMerge [

users/crumb/programs/haskell.nix

@@ -0,0 +1,46 @@
+{ config, lib, pkgs, ... }:
+
+{
+  # Convenient shorthand for quickly opening Haskell REPLs.
+  programs.bash.profileExtra = ''
+    # Start a GHCi REPL with the given packages made available.
+    ghci-with-packages () {
+      nix-shell -p "haskellPackages.ghcWithPackages (p: with p; [ $@ ])" \
+        --run ghci
+    }
+
+    # Run GHC with the given packages made available.
+    ghc-with-packages () {
+      getopt -o "p" -- "$@"
+      while true; do
+        case "$1" in
+          -p)
+            packages="$1"
+            shift 2
+            ;;
+          --)
+            shift
+            break
+            ;;
+        esac
+      done
+
+      if [ $? -ne 0 ]; then
+       echo "Invalid options provided"
+       exit 1
+      fi
+
+      eval set -- "$options"
+
+      nix-shell -p "haskellPackages.ghcWithPackages (p: with p; [ $packages ])" \
+        --run "ghc $@"
+    }
+  '';
+
+  # Some global Cabal configuration.
+  xdg.configFile.".cabal/config".text = ''
+    -- Globally-enable Nix integration.  See
+    -- https://cabal.readthedocs.io/en/3.4/nix-integration.html
+    nix: True
+  '';
+}