;;; modula2.el --- Modula-2 editing support package

;; Author: Michael Schmidt <michael@pbinfo.UUCP> 
;;	Tom Perrine <Perrin@LOGICON.ARPA>
;; Maintainer: FSF
;; Keywords: languages

;; This file is part of GNU Emacs.

;; The authors distributed this without a copyright notice
;; back in 1988, so it is in the public domain.  The original included
;; the following credit:

;; Author Mick Jordan
;; amended Peter Robinson

;;; Commentary:

;; A major mode for editing Modula-2 code.  It provides convenient abbrevs
;; for Modula-2 keywords, knows about the standard layout rules, and supports
;; a native compile command.

;;; Code:

(defgroup modula2 nil
  "Major mode for editing Modula-2 code."
  :prefix "m2-"
  :group 'languages)

;;; Added by Tom Perrine (TEP)
(defvar m2-mode-syntax-table nil
  "Syntax table in use in Modula-2 buffers.")

(defcustom m2-compile-command "m2c"
  "Command to compile Modula-2 programs."
  :type 'string
  :group 'modula2)

(defcustom m2-link-command "m2l"
  "Command to link Modula-2 programs."
  :type 'string
  :group 'modula2)

(defcustom m2-link-name nil
  "Name of the Modula-2 executable."
  :type '(choice (const nil) string)
  :group 'modula2)

(defcustom m2-end-comment-column 75
  "*Column for aligning the end of a comment, in Modula-2."
  :type 'integer
  :group 'modula2)

(if m2-mode-syntax-table
    ()
  (let ((table (make-syntax-table)))
    (modify-syntax-entry ?\\ "\\" table)
    (modify-syntax-entry ?\( ". 1" table)
    (modify-syntax-entry ?\) ". 4" table)
    (modify-syntax-entry ?* ". 23" table)
    (modify-syntax-entry ?+ "." table)
    (modify-syntax-entry ?- "." table)
    (modify-syntax-entry ?= "." table)
    (modify-syntax-entry ?% "." table)
    (modify-syntax-entry ?< "." table)
    (modify-syntax-entry ?> "." table)
    (modify-syntax-entry ?\' "\"" table)
    (setq m2-mode-syntax-table table)))

;;; Added by TEP
(defvar m2-mode-map nil
  "Keymap used in Modula-2 mode.")

(if m2-mode-map ()
  (let ((map (make-sparse-keymap)))
    (define-key map "\^i" 'm2-tab)
    (define-key map "\C-cb" 'm2-begin)
    (define-key map "\C-cc" 'm2-case)
    (define-key map "\C-cd" 'm2-definition)
    (define-key map "\C-ce" 'm2-else)
    (define-key map "\C-cf" 'm2-for)
    (define-key map "\C-ch" 'm2-header)
    (define-key map "\C-ci" 'm2-if)
    (define-key map "\C-cm" 'm2-module)
    (define-key map "\C-cl" 'm2-loop)
    (define-key map "\C-co" 'm2-or)
    (define-key map "\C-cp" 'm2-procedure)
    (define-key map "\C-c\C-w" 'm2-with)
    (define-key map "\C-cr" 'm2-record)
    (define-key map "\C-cs" 'm2-stdio)
    (define-key map "\C-ct" 'm2-type)
    (define-key map "\C-cu" 'm2-until)
    (define-key map "\C-cv" 'm2-var)
    (define-key map "\C-cw" 'm2-while)
    (define-key map "\C-cx" 'm2-export)
    (define-key map "\C-cy" 'm2-import)
    (define-key map "\C-c{" 'm2-begin-comment)
    (define-key map "\C-c}" 'm2-end-comment)
    (define-key map "\C-j"  'm2-newline)
    (define-key map "\C-c\C-z" 'suspend-emacs)
    (define-key map "\C-c\C-v" 'm2-visit)
    (define-key map "\C-c\C-t" 'm2-toggle)
    (define-key map "\C-c\C-l" 'm2-link)
    (define-key map "\C-c\C-c" 'm2-compile)
    (setq m2-mode-map map)))

(defcustom m2-indent 5 
  "*This variable gives the indentation in Modula-2-Mode."
  :type 'integer
  :group 'modula2)
  
;;;###autoload
(defun modula-2-mode ()
  "This is a mode intended to support program development in Modula-2.
All control constructs of Modula-2 can be reached by typing C-c
followed by the first character of the construct.
\\<m2-mode-map>
  \\[m2-begin] begin         \\[m2-case] case
  \\[m2-definition] definition    \\[m2-else] else
  \\[m2-for] for           \\[m2-header] header
  \\[m2-if] if            \\[m2-module] module
  \\[m2-loop] loop          \\[m2-or] or
  \\[m2-procedure] procedure     Control-c Control-w with
  \\[m2-record] record        \\[m2-stdio] stdio
  \\[m2-type] type          \\[m2-until] until
  \\[m2-var] var           \\[m2-while] while
  \\[m2-export] export        \\[m2-import] import
  \\[m2-begin-comment] begin-comment \\[m2-end-comment] end-comment
  \\[suspend-emacs] suspend Emacs     \\[m2-toggle] toggle
  \\[m2-compile] compile           \\[m2-next-error] next-error
  \\[m2-link] link

   `m2-indent' controls the number of spaces for each indentation.
   `m2-compile-command' holds the command to compile a Modula-2 program.
   `m2-link-command' holds the command to link a Modula-2 program."
  (interactive)
  (kill-all-local-variables)
  (use-local-map m2-mode-map)
  (setq major-mode 'modula-2-mode)
  (setq mode-name "Modula-2")
  (make-local-variable 'comment-column)
  (setq comment-column 41)
  (make-local-variable 'm2-end-comment-column)
  (set-syntax-table m2-mode-syntax-table)
  (make-local-variable 'paragraph-start)
  (setq paragraph-start (concat "$\\|" page-delimiter))
  (make-local-variable 'paragraph-separate)
  (setq paragraph-separate paragraph-start)
  (make-local-variable 'paragraph-ignore-fill-prefix)
  (setq paragraph-ignore-fill-prefix t)
;  (make-local-variable 'indent-line-function)
;  (setq indent-line-function 'c-indent-line)
  (make-local-variable 'require-final-newline)
  (setq require-final-newline t)
  (make-local-variable 'comment-start)
  (setq comment-start "(* ")
  (make-local-variable 'comment-end)
  (setq comment-end " *)")
  (make-local-variable 'comment-column)
  (setq comment-column 41)
  (make-local-variable 'comment-start-skip)
  (setq comment-start-skip "/\\*+ *")
  (make-local-variable 'comment-indent-function)
  (setq comment-indent-function 'c-comment-indent)
  (make-local-variable 'parse-sexp-ignore-comments)
  (setq parse-sexp-ignore-comments t)
  (make-local-variable 'font-lock-defaults)
  (setq font-lock-defaults
	'((m3-font-lock-keywords
	   m3-font-lock-keywords-1 m3-font-lock-keywords-2)
	  nil nil ((?_ . "w") (?. . "w") (?< . ". 1") (?> . ". 4")) nil
	  ;; Obsoleted by Emacs 19.35 parse-partial-sexp's COMMENTSTOP.
	  ;(font-lock-comment-start-regexp . "(\\*")
	  ))
  (run-hooks 'm2-mode-hook))

;; Regexps written with help from Ron Forrester <ron@orcad.com>
;; and Spencer Allain <sallain@teknowledge.com>.
(defconst m3-font-lock-keywords-1
  '(
    ;;
    ;; Module definitions.
    ("\\<\\(INTERFACE\\|MODULE\\|PROCEDURE\\)\\>[ \t]*\\(\\sw+\\)?"
     (1 font-lock-keyword-face) (2 font-lock-function-name-face nil t))
    ;;
    ;; Import directives.
    ("\\<\\(EXPORTS\\|FROM\\|IMPORT\\)\\>"
     (1 font-lock-keyword-face)
     (font-lock-match-c-style-declaration-item-and-skip-to-next
      nil (goto-char (match-end 0))
      (1 font-lock-constant-face)))
    ;;
    ;; Pragmas as warnings.
    ;; Spencer Allain <sallain@teknowledge.com> says do them as comments...
    ;; ("<\\*.*\\*>" . font-lock-warning-face)
    ;; ... but instead we fontify the first word.
    ("<\\*[ \t]*\\(\\sw+\\)" 1 font-lock-warning-face prepend)
    )
  "Subdued level highlighting for Modula-3 modes.")

(defconst m3-font-lock-keywords-2
  (append m3-font-lock-keywords-1
   (eval-when-compile
     (let ((m3-types
	    (regexp-opt
	     '("INTEGER" "BITS" "BOOLEAN" "CARDINAL" "CHAR" "FLOAT" "REAL"
	       "LONGREAL" "REFANY" "ADDRESS" "ARRAY" "SET" "TEXT"
	       "MUTEX" "ROOT" "EXTENDED")))
	   (m3-keywords
	    (regexp-opt
	     '("AND" "ANY" "AS" "BEGIN" "BRANDED" "BY" "CASE" "CONST" "DIV"
	       "DO" "ELSE" "ELSIF" "EVAL" "EXCEPT" "EXIT" "FINALLY"
	       "FOR" "GENERIC" "IF" "IN" "LOCK" "LOOP" "METHODS" "MOD" "NOT"
	       "OBJECT" "OF" "OR" "OVERRIDES" "READONLY" "RECORD" "REF"
	       "REPEAT" "RETURN" "REVEAL" "THEN" "TO" "TRY"
	       "TYPE" "TYPECASE" "UNSAFE" "UNTIL" "UNTRACED" "VAR" "VALUE"
	       "WHILE" "WITH")))
	   (m3-builtins
	    (regexp-opt
	     '("ABS" "ADR" "ADRSIZE" "BITSIZE" "BYTESIZE" "CEILING"
	       "DEC" "DISPOSE" "FIRST" "FLOOR" "INC" "ISTYPE" "LAST"
	       "LOOPHOLE" "MAX" "MIN" "NARROW" "NEW" "NUMBER" "ORD"
	       "ROUND" "SUBARRAY" "TRUNC" "TYPECODE" "VAL")))
	   )
       (list
	;;
	;; Keywords except those fontified elsewhere.
	(concat "\\<\\(" m3-keywords "\\)\\>")
	;;
	;; Builtins.
	(cons (concat "\\<\\(" m3-builtins "\\)\\>") 'font-lock-builtin-face)
	;;
	;; Type names.
	(cons (concat "\\<\\(" m3-types "\\)\\>") 'font-lock-type-face)
	;;
	;; Fontify tokens as function names.
	'("\\<\\(END\\|EXCEPTION\\|RAISES?\\)\\>[ \t{]*"
	  (1 font-lock-keyword-face)
	  (font-lock-match-c-style-declaration-item-and-skip-to-next
	   nil (goto-char (match-end 0))
	   (1 font-lock-function-name-face)))
	;;
	;; Fontify constants as references.
	'("\\<\\(FALSE\\|NIL\\|NULL\\|TRUE\\)\\>" . font-lock-constant-face)
	))))
  "Gaudy level highlighting for Modula-3 modes.")

(defvar m3-font-lock-keywords m3-font-lock-keywords-1
  "Default expressions to highlight in Modula-3 modes.")

;; We don't actually have different keywords for Modula-2.  Volunteers?
(defconst m2-font-lock-keywords-1 m3-font-lock-keywords-1
  "Subdued level highlighting for Modula-2 modes.")

(defconst m2-font-lock-keywords-2 m3-font-lock-keywords-2
  "Gaudy level highlighting for Modula-2 modes.")

(defvar m2-font-lock-keywords m2-font-lock-keywords-1
  "Default expressions to highlight in Modula-2 modes.")

(defun m2-newline ()
  "Insert a newline and indent following line like previous line."
  (interactive)
  (let ((hpos (current-indentation)))
    (newline)
    (indent-to hpos)))

(defun m2-tab ()
  "Indent to next tab stop."
  (interactive)
  (indent-to (* (1+ (/ (current-indentation) m2-indent)) m2-indent)))

(defun m2-begin ()
  "Insert a BEGIN keyword and indent for the next line."
  (interactive)
  (insert "BEGIN")
  (m2-newline)
  (m2-tab))

(defun m2-case ()
  "Build skeleton CASE statement, prompting for the <expression>."
  (interactive)
  (let ((name (read-string "Case-Expression: ")))
    (insert "CASE " name " OF")
    (m2-newline)
    (m2-newline)
    (insert "END (* case " name " *);"))
  (end-of-line 0)
  (m2-tab))

(defun m2-definition ()
  "Build skeleton DEFINITION MODULE, prompting for the <module name>."
  (interactive)
  (insert "DEFINITION MODULE ")
  (let ((name (read-string "Name: ")))
    (insert name ";\n\n\n\nEND " name ".\n"))
  (previous-line 3))

(defun m2-else ()
  "Insert ELSE keyword and indent for next line."
  (interactive)
  (m2-newline)
  (backward-delete-char-untabify m2-indent ())
  (insert "ELSE")
  (m2-newline)
  (m2-tab))

(defun m2-for ()
  "Build skeleton FOR loop statement, prompting for the loop parameters."
  (interactive)
  (insert "FOR ")
  (let ((name (read-string "Loop Initialiser: ")) limit by)
    (insert name " TO ")
    (setq limit (read-string "Limit: "))
    (insert limit)
    (setq by (read-string "Step: "))
    (if (not (string-equal by ""))
	(insert " BY " by))
    (insert " DO")
    (m2-newline)
    (m2-newline)
    (insert "END (* for " name " to " limit " *);"))
  (end-of-line 0)
  (m2-tab))

(defun m2-header ()
  "Insert a comment block containing the module title, author, etc."
  (interactive)
  (insert "(*\n    Title: \t")
  (insert (read-string "Title: "))
  (insert "\n    Created:\t")
  (insert (current-time-string))
  (insert "\n    Author: \t")
  (insert (user-full-name))
  (insert (concat "\n\t\t<" (user-login-name) "@" (system-name) ">\n"))
  (insert "*)\n\n"))

(defun m2-if ()
  "Insert skeleton IF statement, prompting for <boolean-expression>."
  (interactive)
  (insert "IF ")
  (let ((thecondition (read-string "<boolean-expression>: ")))
    (insert thecondition " THEN")
    (m2-newline)
    (m2-newline)
    (insert "END (* if " thecondition " *);"))
  (end-of-line 0)
  (m2-tab))

(defun m2-loop ()
  "Build skeleton LOOP (with END)."
  (interactive)
  (insert "LOOP")
  (m2-newline)
  (m2-newline)
  (insert "END (* loop *);")
  (end-of-line 0)
  (m2-tab))

(defun m2-module ()
  "Build skeleton IMPLEMENTATION MODULE, prompting for <module-name>."
  (interactive)
  (insert "IMPLEMENTATION MODULE ")
  (let ((name (read-string "Name: ")))
    (insert name ";\n\n\n\nEND " name ".\n")
    (previous-line 3)
    (m2-header)
    (m2-type)
    (newline)
    (m2-var)
    (newline)
    (m2-begin)
    (m2-begin-comment)
    (insert " Module " name " Initialisation Code "))
  (m2-end-comment)
  (newline)
  (m2-tab))

(defun m2-or ()
  (interactive)
  (m2-newline)
  (backward-delete-char-untabify m2-indent)
  (insert "|")
  (m2-newline)
  (m2-tab))

(defun m2-procedure ()
  (interactive)
  (insert "PROCEDURE ")
  (let ((name (read-string "Name: " ))
	args)
    (insert name " (")
    (insert (read-string "Arguments: ") ")")
    (setq args (read-string "Result Type: "))
    (if (not (string-equal args ""))
	(insert " : " args))
    (insert ";")
    (m2-newline)
    (insert "BEGIN")
    (m2-newline)
    (m2-newline)
    (insert "END ")
    (insert name)
    (insert ";")
    (end-of-line 0)
    (m2-tab)))

(defun m2-with ()
  (interactive)
  (insert "WITH ")
  (let ((name (read-string "Record-Type: ")))
    (insert name)
    (insert " DO")
    (m2-newline)
    (m2-newline)
    (insert "END (* with " name " *);"))
  (end-of-line 0)
  (m2-tab))

(defun m2-record ()
  (interactive)
  (insert "RECORD")
  (m2-newline)
  (m2-newline)
  (insert "END (* record *);")
  (end-of-line 0)
  (m2-tab))

(defun m2-stdio ()
  (interactive)
  (insert "
FROM TextIO IMPORT 
   WriteCHAR, ReadCHAR, WriteINTEGER, ReadINTEGER,
   WriteCARDINAL, ReadCARDINAL, WriteBOOLEAN, ReadBOOLEAN,
   WriteREAL, ReadREAL, WriteBITSET, ReadBITSET,
   WriteBasedCARDINAL, ReadBasedCARDINAL, WriteChars, ReadChars,
   WriteString, ReadString, WhiteSpace, EndOfLine;

FROM SysStreams IMPORT sysIn, sysOut, sysErr;

"))

(defun m2-type ()
  (interactive)
  (insert "TYPE")
  (m2-newline)
  (m2-tab))

(defun m2-until ()
  (interactive)
  (insert "REPEAT")
  (m2-newline)
  (m2-newline)
  (insert "UNTIL ")
  (insert (read-string "<boolean-expression>: ") ";")
  (end-of-line 0)
  (m2-tab))

(defun m2-var ()
  (interactive)
  (m2-newline)
  (insert "VAR")
  (m2-newline)
  (m2-tab))

(defun m2-while ()
  (interactive)
  (insert "WHILE ")
  (let ((name (read-string "<boolean-expression>: ")))
    (insert name " DO" )
    (m2-newline)
    (m2-newline)
    (insert "END (* while " name " *);"))
  (end-of-line 0)
  (m2-tab))

(defun m2-export ()
  (interactive)
  (insert "EXPORT QUALIFIED "))

(defun m2-import ()
  (interactive)
  (insert "FROM ")
  (insert (read-string "Module: "))
  (insert " IMPORT "))

(defun m2-begin-comment ()
  (interactive)
  (if (not (bolp))
      (indent-to comment-column 0))
  (insert "(*  "))

(defun m2-end-comment ()
  (interactive)
  (if (not (bolp))
      (indent-to m2-end-comment-column))
  (insert "*)"))

(defun m2-compile ()
  (interactive)
  (compile (concat m2-compile-command " " (buffer-name))))

(defun m2-link ()
  (interactive)
  (if m2-link-name
      (compile (concat m2-link-command " " m2-link-name))
    (compile (concat m2-link-command " "
		     (setq m2-link-name (read-string "Name of executable: "
						     (buffer-name)))))))

(defun m2-execute-monitor-command (command)
  (let* ((shell shell-file-name)
	 (csh (equal (file-name-nondirectory shell) "csh")))
    (call-process shell nil t t "-cf" (concat "exec " command))))

(defun m2-visit ()
  (interactive)
  (let ((deffile nil)
	(modfile nil)
	modulename)
    (save-excursion
      (setq modulename
	    (read-string "Module name: "))
      (switch-to-buffer "*Command Execution*")
      (m2-execute-monitor-command (concat "m2whereis " modulename))
      (goto-char (point-min))
      (condition-case ()
	  (progn (re-search-forward "\\(.*\\.def\\) *$")
		 (setq deffile (buffer-substring (match-beginning 1)
						 (match-end 1))))
	(search-failed ()))
      (condition-case ()
	  (progn (re-search-forward "\\(.*\\.mod\\) *$")
		 (setq modfile (buffer-substring (match-beginning 1)
						 (match-end 1))))
	(search-failed ()))
      (if (not (or deffile modfile))
	  (error "I can find neither definition nor implementation of %s"
		 modulename)))
    (cond (deffile
	    (find-file deffile)
	    (if modfile
		(save-excursion
		  (find-file modfile))))
	  (modfile
	   (find-file modfile)))))

(defun m2-toggle ()
  "Toggle between .mod and .def files for the module."
  (interactive)
  (cond ((string-equal (substring (buffer-name) -4) ".def")
	 (find-file-other-window
	  (concat (substring (buffer-name) 0 -4) ".mod")))
	((string-equal (substring (buffer-name) -4) ".mod")
	 (find-file-other-window
	  (concat (substring (buffer-name) 0 -4)  ".def")))
	((string-equal (substring (buffer-name) -3) ".mi")
	 (find-file-other-window
	  (concat (substring (buffer-name) 0 -3)  ".md")))
	((string-equal (substring (buffer-name) -3) ".md")
	 (find-file-other-window
	  (concat (substring (buffer-name) 0 -3)  ".mi")))))

(provide 'modula2)

;;; modula2.el ends here