Add pretty-symbols-alist support to scala

Closes #2705

Co-authored-by: Ashkan <ashkan.aleali@gmail.com>

modules/lang/scala/config.el

@@ -16,7 +16,34 @@
     comment-line-break-function #'+scala-comment-indent-new-line-fn)
 
   (when (featurep! +lsp)
-    (add-hook 'scala-mode-local-vars-hook #'lsp!)))
+    (add-hook 'scala-mode-local-vars-hook #'lsp!))
+
+  (set-pretty-symbols! 'scala-mode
+    ;; Functional
+    :def "def"
+    :composition  "compose"
+    ;; HKT
+    :lambda       "Lambda"
+    ;; Types
+    :null         "none"
+    :null         "None"
+    :true         "true"
+    :false        "false"
+    :int          "Int"
+    :str          "String"
+    :float        "Float"
+    :bool         "Boolean"
+    :list         "List"
+    ;; Flow
+    :for          "for"
+    :not          "!"
+    :and          "&&"
+    :or           "||"
+    :yield        "yield"
+    ;; Other
+    :union        "union"
+    :intersect    "intersect"
+    :diff         "diff"))
 
 
 (use-package! sbt-mode

modules/ui/pretty-code/config.el

@@ -20,6 +20,7 @@
     :float         "ℝ"
     :str           "𝕊"
     :bool          "𝔹"
+    :list          "𝕃"
     ;; Flow
     :not           "￢"
     :in            "∈"
@@ -31,6 +32,9 @@
     :return        "⟼"
     :yield         "⟻"
     ;; Other
+    :union         "⋃"
+    :intersect     "∩"
+    :diff          "∖"
     :tuple         "⨂"
     :pipe          "" ;; FIXME: find a non-private char
     :dot           "•")