;;; ztl-mode.el --- Major mode for ZTL programs

;;;###autoload
(add-to-list 'auto-mode-alist '("\\.ztl\\'" . ztl-mode))

(defconst ztl-mode-syntax-table
  (let ((syn-table (make-syntax-table)))
    (modify-syntax-entry ?! "< b" syn-table) ; Line comment (extend to end of line)
    (modify-syntax-entry ?\[ "(]" syn-table)
    (modify-syntax-entry ?\] ")[" syn-table)
    (modify-syntax-entry ?\" "\"" syn-table)
    syn-table))

(defvar ztl-keywords
  '("fn" "to" "in" "is" "as" "use" "set" "if" "else" "for" "loop"
    "while" "push" "pop" "return" "const" "type" "this" "eq" "ne"
    "mod" "not" "and" "or" "xor" "band" "bor" "bxor" "srl" "sll"))

(defvar ztl-types
  '("char" "str" "i8" "i16" "i32" "i64" "i128" "f8" "f16" "f32"
    "f64" "f128" "9p" "9pmsg"))

(defvar ztl-font-lock-keywords
  `(
    ;; Comments
    ("!.*$" 0 font-lock-comment-face) 
    ("!!\\(.*?\\)!!" 0 font-lock-comment-face)

    ;; Keywords
    (,(concat "\\<" (regexp-opt ztl-keywords) "\\>") 0 font-lock-keyword-face)

    ;; Types
    (,(concat "\\<" (regexp-opt ztl-types) "\\>") 0 font-lock-type-face)

    ;; Constants
    ("\\_<\\(true\\|false\\)\\>" 1 font-lock-constant-face)

    ;; Structs (PascalCased)
    ("\\_<\\([A-Z][a-zA-Z0-9_]+\\)\\>" 1 font-lock-type-face)

    ;; Function definitions
    ("\\_<fn\\>\\s-+\\(\\w+\\)\\s-*(" (1 font-lock-function-name-face))

    ;; Function calls
    ("\\_<\\(\\w+\\)\\s-*(\\>" (1 font-lock-function-name-face))
))

(define-derived-mode ztl-mode prog-mode "ZTL"
  "Major mode for ZTL programming."
  :syntax-table ztl-mode-syntax-table
  (setq font-lock-multiline t)
  (setq-local comment-start "!! ")
  (setq-local comment-end "!!")
  (setq-local comment-start-skip "!!+\\s-*")
  (set (make-local-variable 'font-lock-defaults)
       '(ztl-font-lock-keywords)))

(provide 'ztl-mode)