Add support for Lua

extensions/lua-mode/lem-lua-mode.asd

@@ -0,0 +1,5 @@
+(defsystem "lem-lua-mode"
+  :depends-on ("lem" "yason")
+  :serial t
+  :components ((:file "lua-mode")
+               (:file "lsp-config")))

extensions/lua-mode/lsp-config.lisp

@@ -0,0 +1,12 @@
+(defpackage :lem-lua-mode/lsp-config
+  (:use :cl :lem-lsp-mode :lem-lsp-base/type))
+
+(in-package :lem-lua-mode/lsp-config)
+
+(define-language-spec (lua-spec lem-lua-mode:lua-mode)
+  :language-id "lua"
+  ;; I have no idea what a correct file may identify a root of a Lua project
+  :root-uri-patterns '(".git")
+  :command '("lua-language-server")
+  :readme-url "https://github.com/luals/lua-language-server"
+  :connection-mode :stdio)

extensions/lua-mode/lua-mode.lisp

@@ -0,0 +1,82 @@
+(defpackage :lem-lua-mode
+  (:use :cl
+        :lem
+        :lem/completion-mode
+        :lem/language-mode
+        :lem/language-mode-tools)
+  (:import-from :lem/tmlanguage :load-tmlanguage)
+  (:export :*lua-mode-hook* :lua-mode))
+
+(in-package :lem-lua-mode)
+
+
+;; From: https://www.lua.org/manual/5.1/manual.html#2.1
+(defvar *lua-keywords*
+  '("and"       "break"     "do"       "else"     "elseif"
+    "end"       "false"     "for"       "function"  "if"
+    "in"        "local"     "nil"       "not"       "or"
+    "repeat"    "return"    "then"      "true"      "until"     "while"))
+
+(defvar *lua-boolean-literals*
+  '("true" "false"))
+
+(defvar *lua-null-literal*
+  '("nil"))
+
+(defvar *lua-operators*
+  '( "+"     "-"     "*"     "/"     "%"     "^"     "#"
+    "==" "~=" "<="    ">="    "<"     ">"     "="
+    "("     ")" "{"     "}"     "["     "]"
+    ";"     ":"     ","     "."     ".."    "..."))
+
+(defvar *lua-builtin-regex*
+  "\\b(assert|collectgarbage|dofile|error|getfenv|getmetatable|ipairs|loadfile|loadstring|module|next|pairs|pcall|print|rawequal|rawget|rawset|require|select|setfenv|setmetatable|tonumber|tostring|type|unpack|xpcall|coroutine\\.(create|resume|running|status|wrap|yield)|string\\.(byte|char|dump|find|format|gmatch|gsub|len|lower|match|rep|reverse|sub|upper)|table\\.(concat|insert|maxn|remove|sort)|math\\.(abs|acos|asin|atan1?|ceil|cosh?|deg|exp|floor|fmod|frexp|ldexp|log|log10|max|min|modf|pow|rad|random|randomseed|sinh?|sqrt|tanh?)|io\\.(close|flush|input|lines|open|output|popen|read|tmpfile|type|write)|os\\.(clock|date|difftime|execute|exit|getenv|remove|rename|setlocale|time|tmpname)|package\\.(cpath|loaded|loadlib|path|preload|seeall)|debug\\.(debug|[gs]etfenv|[gs]ethook|getinfo|[gs]etlocal|[gs]etmetatable|getregistry|[gs]etupvalue|traceback))\\b")
+
+(defun tokens (boundary strings)
+  (let ((alternation
+          `(:alternation ,@(sort (copy-list strings) #'> :key #'length))))
+    (if boundary
+        `(:sequence ,boundary ,alternation ,boundary)
+        alternation)))
+
+(defun make-tmlanguage-lua ()
+  (let* ((patterns (make-tm-patterns
+                    (make-tm-line-comment-region "--")
+                    (make-tm-string-region "\"")
+                    (make-tm-string-region "'")
+                    (make-tm-match *lua-builtin-regex*
+                                   :name 'syntax-function-name-attribute)
+                    (make-tm-match (tokens :word-boundary
+                                           (append *lua-boolean-literals*
+                                                   *lua-null-literal*))
+                                   :name 'syntax-constant-attribute)
+                    (make-tm-match (tokens :word-boundary *lua-keywords*)
+                                   :name 'syntax-keyword-attribute)
+                    (make-tm-match (tokens nil *lua-operators*)
+                                   :name 'syntax-builtin-attribute))))
+    (make-tmlanguage :patterns patterns)))
+
+
+(defvar *lua-syntax-table*
+  (let ((table (make-syntax-table
+                :space-chars '(#\space #\tab #\newline)
+                :symbol-chars '(#\_)
+                :paren-pairs '((#\( . #\))
+                               (#\{ . #\})
+                               (#\[ . #\]))
+                :string-quote-chars '(#\" #\')
+                :line-comment-string "\-\-"
+                :block-comment-pairs '(("--[[" . "]]"))))
+        (tmlanguage (make-tmlanguage-lua)))
+    (set-syntax-parser table tmlanguage)
+    table))
+
+(define-major-mode lua-mode language-mode
+    (:name "Lua"
+     :syntax-table *lua-syntax-table*
+     :mode-hook *lua-mode-hook*)
+  (setf (variable-value 'enable-syntax-highlight) t
+        (variable-value 'tab-width) 2
+        (variable-value 'line-comment) "--"))
+
+(define-file-type ("lua") lua-mode)

lem.asd

@@ -250,7 +250,8 @@
                "lem-documentation-mode"
                "lem-elisp-mode"
                "lem-markdown-mode"
-               "lem-color-preview"))
+               "lem-color-preview"
+               "lem-lua-mode"))
 
 (defsystem "lem/legit"
   :serial t