Add scheme module

Adds scheme module with geiser.

modules/lang/scheme/config.el

@@ -0,0 +1,46 @@
+;;; lang/scheme/config.el -*- lexical-binding: t; -*-
+
+(add-hook 'scheme-mode-hook #'rainbow-delimiters-mode)
+
+(defun +scheme/impls ()
+  `( ,@(when (featurep! +racket)  '(racket))
+     ,@(when (featurep! +guile)   '(guile))
+     ,@(when (featurep! +chicken) '(chicken))
+     ,@(when (featurep! +mit)     '(mit))
+     ,@(when (featurep! +chibi)   '(chibi))
+     ,@(when (featurep! +chez)    '(chez)) ()))
+
+(def-package! geiser
+  :mode ("\\.scm\\'" . scheme-mode)
+  :mode ("\\.ss\\'"  . scheme-mode)
+  :commands (geiser)
+  :init
+  (setq geiser-active-implementations #'+scheme/impls)
+  (set-repl-handler! 'scheme-mode '+scheme/repl)
+  (set-eval-handler! 'scheme-mode #'geiser-eval-region)
+  (set-lookup-handlers! 'scheme-mode
+    :definition #'geiser-edit-symbol-at-point
+    :documentation #'geiser-doc-symbol-at-point)
+  :config
+  (map! (:localleader
+          (:map scheme-mode-map
+            "'" #'geiser-mode-switch-to-repl
+            "s" #'geiser-set-scheme
+
+            (:prefix ("e" . "eval")
+              "b" #'geiser-eval-buffer
+              "B" #'geiser-eval-buffer-and-go
+              "e" #'geiser-eval-definition
+              "E" #'geiser-eval-definition-and-go
+              "r" #'geiser-eval-region
+              "R" #'geiser-eval-region-and-go)
+
+            (:prefix ("h" . "help")
+              "d" 'geiser-autodoc)
+
+            (:prefix ("r" . "repl")
+              "b" #'geiser-switch-to-repl
+              "q" #'geiser-repl-exit
+              "r" #'geiser-restart-repl
+              "R" #'geiser-reload
+              "c" #'geiser-repl-clear-buffer)))))