From cffe715e3017b8ab9a956b1dab967f83d72a3b49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Madeleine=20Sydney=20=C5=9Alaga?= <msyds@deertopia.net>
Date: Sat, 29 Aug 2026 03:03:18 -0600
Subject: [PATCH] feat(emacs): haskell-ts-mode

---
 modules/home/haskell.nix                      | 16 ++++-
 .../home/users/msyds/emacs/lisp/syd/comint.el |  3 +-
 .../users/msyds/emacs/lisp/syd/haskell.el     | 61 ++++++++++++++++++-
 .../home/users/msyds/emacs/lisp/syd/tabs.el   |  6 +-
 .../home/users/msyds/emacs/nix/treesit.nix    | 35 +++++++++--
 5 files changed, 110 insertions(+), 11 deletions(-)

diff --git a/modules/home/haskell.nix b/modules/home/haskell.nix
index dda3918..460ce8b 100644
--- a/modules/home/haskell.nix
+++ b/modules/home/haskell.nix
@@ -12,8 +12,20 @@ in {
       builtins.readFile ./haskell/ghc-with-packages.sh;
 
     home.file.".ghc/ghci.conf".text = ''
-      :set prompt "\x1b[38;5;5mλ>\x1b[0m "
-      :set prompt-cont "\x1b[38;5;5m|>\x1b[0m "
+      :{
+      ghci_set_prompt :: IO String
+      ghci_set_prompt = do
+        term <- System.Environment.Blank.getEnvDefault "TERM" ""
+        let (prompt,promptCont) =
+              if Data.List.isPrefixOf "xterm-" term
+                then ("\x1b[38;5;5mλ>\x1b[0m ", "\x1b[38;5;5m|>\x1b[0m ")
+                else ("λ> ", "|> ")
+        pure . unlines $
+          [ ":set prompt " ++ show prompt
+          , ":set prompt-cont " ++ show promptCont
+          ]
+      :}
+      :cmd ghci_set_prompt
       :set -interactive-print=Text.Pretty.Simple.pPrint
       :m + Text.Show.Functions
       :unset +r
diff --git a/modules/home/users/msyds/emacs/lisp/syd/comint.el b/modules/home/users/msyds/emacs/lisp/syd/comint.el
index 01cc347..40e475b 100755
--- a/modules/home/users/msyds/emacs/lisp/syd/comint.el
+++ b/modules/home/users/msyds/emacs/lisp/syd/comint.el
@@ -18,7 +18,8 @@
     :states '(normal insert)
     "C-k" #'comint-previous-input
     "C-j" #'comint-next-input
-    "C-s" #'consult-history)
+    "C-s" #'consult-history
+    "<return>" #'comint-send-input)
   (general-def
     :keymaps 'comint-mode-map
     :states 'insert
diff --git a/modules/home/users/msyds/emacs/lisp/syd/haskell.el b/modules/home/users/msyds/emacs/lisp/syd/haskell.el
index b27fbf5..a732174 100644
--- a/modules/home/users/msyds/emacs/lisp/syd/haskell.el
+++ b/modules/home/users/msyds/emacs/lisp/syd/haskell.el
@@ -9,6 +9,18 @@
   (require 'inf-haskell)
   (run-haskell))
 
+(defun syd-haskell-ts-open-repl ()
+  "Open a Haskell REPL."
+  (interactive)
+  (haskell-ts-run)
+  (pop-to-buffer haskell-ts-ghci-buffer-name))
+
+(defun syd-haskell-ts-eval-region (beg end)
+  (haskell-ts--send-region beg end))
+
+(defun syd-haskell-ts-load-buffer ()
+  (haskell-ts-load-file))
+
 (defun syd-haskell-evil-open-above ()
   "Opens a line above the current, following Haskell-mode's indentation"
   (interactive)
@@ -38,7 +50,9 @@
   :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))
+           (haskell-process-auto-import-loaded-modules t)
+           (haskell-ts-inferior-history-file
+            (file-name-concat syd-data-dir "haskell-ts-inferior-history")))
   :general
   (:keymaps 'haskell-mode-map
    :states '(normal visual motion emacs insert)
@@ -62,13 +76,56 @@
   (add-to-list 'haskell-font-lock-quasi-quote-modes '("wats" . wat-mode))
   (add-to-list 'haskell-font-lock-quasi-quote-modes '("expr" . wat-mode)))
 
+(use-package consult-hoogle
+  :config
+  (syd-push shackle-rules
+            `("*hoogle-search*"
+              :select t :size 0.5 :popup t :align bottom)))
+
+(use-package haskell-ts-mode
+  :straight (:type git
+             :host github
+             :repo "dschrempf/haskell-ts-mode")
+  :custom ((haskell-ts-font-lock-level 4)
+           (haskell-ts-ghci "ghci")
+           (haskell-ts-inferior-prompt-regexp
+            (rx bol (or "λ> " "|> "))))
+  :general
+  (:keymaps 'haskell-ts-mode-map
+   :states '(normal motion)
+   :major-modes t
+   :prefix syd-localleader-key
+   :non-normal-prefix syd-alt-localleader-key
+   "h s" #'syd-haskell-hoogle-start-server
+   "h q" #'haskell-hoogle-kill-server
+   "c" #'haskell-cabal-visit-file)
+  :config
+  (add-to-list 'completion-ignored-extensions ".hi")
+  (syd-add-hook 'haskell-ts-mode-hook
+    (defun syd-haskell-configure-indent-h ()
+      (setq-local tab-width 2)
+      ;; (setq-local indent-line-function #'tab-to-tab-stop)
+      (indent-tabs-mode -1))
+    (defun syd-haskell-configure-evil-h ()
+      (setq-local evil-symbol-word-search nil)))
+  (syd-handle '(haskell-ts-mode)
+    :repl #'syd-haskell-ts-open-repl
+    :eval-region #'syd-haskell-ts-eval-region
+    :load-buffer #'syd-haskell-ts-load-buffer)
+  (syd-defadvice syd-haskell-hide-repl-h (old &rest rs)
+    :around #'haskell-ts-show-repl
+    (save-window-excursion
+      (apply old rs))))
+
 (use-package lsp-haskell
   :defer t
   :custom ((lsp-haskell-server-path "haskell-language-server"))
   :init
   (add-hook 'haskell-mode-hook #'lsp-deferred 'append)
   (add-hook 'haskell-literate-mode-hook #'lsp-deferred 'append)
-  (syd-add-hook '(haskell-mode-hook haskell-literate-mode-hook)
+  (add-hook 'haskell-ts-mode-hook #'lsp-deferred 'append)
+  (syd-add-hook '(haskell-ts-mode-hook
+                  haskell-mode-hook haskell-literate-mode-hook)
     (defun syd-haskell-configure-lsp-h ()
       ;; it often highlights list literals and quasiquotes which
       ;; gets reaaaally annoying.
diff --git a/modules/home/users/msyds/emacs/lisp/syd/tabs.el b/modules/home/users/msyds/emacs/lisp/syd/tabs.el
index d5d7d31..a219bfb 100644
--- a/modules/home/users/msyds/emacs/lisp/syd/tabs.el
+++ b/modules/home/users/msyds/emacs/lisp/syd/tabs.el
@@ -1,7 +1,11 @@
 ;;; -*- lexical-binding: t -*-
 (require 'syd/base)
 
-;; Disable tabs by default.
+;; Tabs, not spaces.
 (setq-default indent-tabs-mode nil)
+(setq-default tab-width 2)
+
+(use-package kakapo-mode
+  :hook ((prog-mode . kakapo-mode)))
 
 (provide 'syd/tabs)
diff --git a/modules/home/users/msyds/emacs/nix/treesit.nix b/modules/home/users/msyds/emacs/nix/treesit.nix
index a0b4e8c..f1b4994 100644
--- a/modules/home/users/msyds/emacs/nix/treesit.nix
+++ b/modules/home/users/msyds/emacs/nix/treesit.nix
@@ -6,9 +6,34 @@ in {
     enable = lib.mkEnableOption "Treesitter grammars";
   };
 
-  config = lib.mkIf cfg.enable {
-    sydnix.emacs.emacsPackages = epkgs: [
-      epkgs.treesit-grammars.with-all-grammars
-    ];
-  };
+  config = lib.mkIf cfg.enable
+    # https://github.com/dschrempf/haskell-ts-mode/blob/1c236f00dc214e546124a5dac90902ba62500c15/flake.nix#L40-L55
+    (let
+      grammars = pkgs.tree-sitter-grammars.overrideScope (ts-final: ts-prev: {
+        tree-sitter-haskell = ts-prev.tree-sitter-haskell.overrideAttrs (prev:
+          let rev = "1ad6077a1fb776c255836e00aeb6da57ba564b6a";
+          in {
+            version = "unstable-2026-07-07-${builtins.substring 0 7 rev}";
+            src = pkgs.fetchFromGitHub {
+              owner = "dschrempf";
+              repo = "tree-sitter-haskell";
+              inherit rev;
+              hash = "sha256-kC6HwImFRx5HUY7NDLAA0I/DaSstQ94dWxA9+lMx2gI=";
+            };
+            nativeBuildInputs = (prev.nativeBuildInputs or [ ]) ++ [
+              pkgs.nodejs
+              pkgs.tree-sitter
+            ];
+            preBuild = ''
+              tree-sitter generate
+            '';
+          });
+      });
+    in {
+      sydnix.emacs.emacsPackages = epkgs: [
+        (epkgs.treesit-grammars.with-grammars (_ps:
+          grammars.allGrammars
+        ))
+      ];
+    });
 }