Sunday, March 4

Unrealscript mode for Emacs

Edit: I've since abandoned this mode and moved to a simpler (but less buggy) version not based on cc-mode that lives here

;;; unrealscript-mode.el --- unrealscript mode derived from cc-mode

;; Author: 2007 John Connors
;; Maintainer: John Connors <johnc at yagc dot co dot uk>
;; Created: March 2007
;; Version: See cc-mode.el
;; Keywords: unrealscript cc-mode languages oop

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; Note: The interface used in this file requires CC Mode 5.30 or
;; later.

;;; Code:

(require 'cc-mode)

;; These are only required at compile time to get the sources for the
;; language constants. (The cc-fonts require and the font-lock
;; related constants could additionally be put inside an
;; (eval-after-load "font-lock" ...) but then some trickery is
;; necessary to get them compiled.)
(require 'cc-langs)
(require 'cc-fonts))

;; Make our mode known to the language constant system. Use Java
;; mode as the fallback for the constants we don't change here.
;; This needs to be done also at compile time since the language
;; constants are evaluated then.
(c-add-language 'unrealscript-mode 'java-mode))

;; unrealscript has no boolean but a string and a vector type.
(c-lang-defconst c-primitive-type-kwds
'("bool" "name" "object" "actor" "string" "vector")
(delete "boolean"
;; Use append to not be destructive on the
;; return value below.
;; Due to the fallback to Java, we need not give
;; a language to `c-lang-const'.
(c-lang-const c-primitive-type-kwds)

(c-lang-defconst c-type-modifier-keywds
'("config" "deprecated" "edfindable" "editconstarray"
"editinline" "export" "noexport" "globalconfig"
"localized" "const" "editconst" "input" "travel"
"skip" "export")
(c-lang-const c-type-modifier-keywds)

;; "Keywords introducing extra declaration specifiers in the region
;; between the header and the body \(i.e. the \"K&R-region\") in
;; declarations."

(c-lang-defconst c-postfix-decl-spec-kwds
'("abstract" "native" "nativereplication" "nousercreate" "within"
"perobjectconfig" "transient" "noexport" "dependson" "exportstructs"
"cacheexempt" "hidedropdown" "parseconfig" "dontcollapsecategories"
"collapsecategories" "hidecategories" "showcategories" "placeable"
"notplaceable" "instanced")
(c-lang-const c-postfix-decl-spec-kwds)

;; "Keywords that may be followed by a comma separated list of type
;; identifiers, where each optionally can be prefixed by keywords. (Can
;; also be used for the special case when the list can contain only one
;; element.)"
(c-lang-defconst c-type-list-kwds
(cons "within"
(c-lang-const c-type-list-kwds)))

;; Function declarations begin with "function" in this language.
;; There's currently no special keyword list for that in CC Mode, but
;; treating it as a modifier works fairly well.
(c-lang-defconst c-modifier-kwds
(c-lang-const c-modifier-kwds)))

(c-lang-defconst c-block-decls-with-vars
(c-lang-const c-other-block-decl-kwds)))

;; "Keywords that may be followed by a parenthesis expression that doesn't
;; contain type identifiers."
(c-lang-defconst c-paren-nontype-kwds
'("state" "var")
(c-lang-const c-paren-nontype-kwds)

;; "Keywords that may be followed by a parenthesis expression containing
;; type identifiers separated by arbitrary tokens."
(c-lang-defconst c-paren-type-kwds
'("config" "dependson")
(c-lang-const c-paren-type-kwds)))

;; ;; No cpp in this language, but there's still a "#exec" directive to
;; ;; fontify. (The definitions for the extra keywords above are enough
;; ;; to incorporate them into the fontification regexps for types and
;; ;; keywords, so no additional font-lock patterns are required.)
;; (c-lang-defconst c-cpp-matchers
;; unrealscript
;; ;; Use the eval form for `font-lock-keywords' to be able to use
;; ;; the `c-preprocessor-face-name' variable that maps to a
;; ;; suitable face depending on the (X)Emacs version.
;; '(eval . (list "^\\s *\\(#exec\\)\\>\\(.*\\)"
;; (list 1 c-preprocessor-face-name)
;; '(2 font-lock-string-face))))

(defcustom unrealscript-font-lock-extra-types nil
"*List of extra types (aside from the type keywords) to recognize in Unrealscript mode.
Each list item should be a regexp matching a single identifier."

(defconst unrealscript-font-lock-keywords-1
(c-lang-const c-matchers-1 unrealscript)
"Minimal highlighting for UNREALSCRIPT mode.")

(defconst unrealscript-font-lock-keywords-2
(c-lang-const c-matchers-2 unrealscript)
"Fast normal highlighting for UNREALSCRIPT mode.")

(defconst unrealscript-font-lock-keywords-3
(c-lang-const c-matchers-3 unrealscript)
"Accurate normal highlighting for UNREALSCRIPT mode.")

(defvar unrealscript-font-lock-keywords unrealscript-font-lock-keywords-3
"Default expressions to highlight in UNREALSCRIPT mode.")

(defvar unrealscript-mode-syntax-table nil
"Syntax table used in unrealscript-mode buffers.")
(or unrealscript-mode-syntax-table
(setq unrealscript-mode-syntax-table
(funcall (c-lang-const c-make-mode-syntax-table unrealscript))))

(defvar unrealscript-mode-abbrev-table nil
"Abbreviation table used in unrealscript-mode buffers.")

(c-define-abbrev-table 'unrealscript-mode-abbrev-table
;; Keywords that if they occur first on a line might alter the
;; syntactic context, and which therefore should trig reindentation
;; when they are completed.
'(("else" "else" c-electric-continued-statement 0)
("while" "while" c-electric-continued-statement 0)))

(defvar unrealscript-mode-map (let ((map (c-make-inherited-keymap)))
;; Add bindings which are only useful for UNREALSCRIPT
"Keymap used in unrealscript-mode buffers.")

(easy-menu-define unrealscript-menu unrealscript-mode-map "UNREALSCRIPT Mode Commands"
;; Can use `unrealscript' as the language for `c-mode-menu'
;; since its definition covers any language. In
;; this case the language is used to adapt to the
;; nonexistence of a cpp pass and thus removing some
;; irrelevant menu alternatives.
(cons "UNREALSCRIPT" (c-lang-const c-mode-menu unrealscript)))

(add-to-list 'auto-mode-alist '("\\.uc\\'" . unrealscript-mode))

(defun unrealscript-mode ()
"Major mode for editing UNREALSCRIPT UnrealScript is a
Java-like object-orientated programming (OOP) language created by
Epic Games for programming in-game content for the UnrealEngine.

The hook `
c-mode-common-hook' is run with no args at mode
initialization, then `

Key bindings:

(c-initialize-cc-mode t)
(set-syntax-table unrealscript-mode-syntax-table)
(setq major-mode 'unrealscript-mode
mode-name "UnrealScript"
local-abbrev-table unrealscript-mode-abbrev-table
abbrev-mode t)
(use-local-map c-mode-map)
;; `c-init-language-vars' is a macro that is expanded at compile
;; time to a large `setq' with all the language variables and their
;; customized values for our language.
(c-init-language-vars unrealscript-mode)
;; `c-common-init' initializes most of the components of a CC Mode
;; buffer, including setup of the mode menu, font-lock, etc.
;; There's also a lower level routine `c-basic-common-init' that
;; only makes the necessary initialization to get the syntactic
;; analysis and similar things working.
(c-common-init 'unrealscript-mode)
(easy-menu-add unrealscript-menu)
(run-hooks 'c-mode-common-hook)
(run-hooks 'unrealscript-mode-hook)
(setq font-lock-keywords-case-fold-search t)

(provide 'unrealscript-mode)


SamB said...

I'm noticing that, besides all the missing keywords, this mode doesn't fontify lines starting with # (probably related to basing it on java-mode).

Of course, I've also noticed the lack of imenu/speedbar support, but that seems to involve some rather icky regular expressions, so I can't really complain there :-).

And one minor nit: there's no defvar/defcustom for the mode hook, which makes it a bit less discoverable than it could be.

John Connors said...

It was my first crack at an Emacs Mode (or Elisp, really).

I actually rewrote the whole thing sometime later, without the java mode dependency.