;; Perl code editing commands for GNU Emacs;;   Copyright (C) 1990  William F. Mann;; Adapted from C code editing commands 'c-mode.el', Copyright 1987 by the;; Free Software Foundation, under terms of its General Public License.;; This file may be made part of GNU Emacs at the option of the FSF, or;; of the perl distribution at the option of Larry Wall.;; This code is distributed in the hope that it will be useful,;; but WITHOUT ANY WARRANTY.  No author or distributor;; accepts responsibility to anyone for the consequences of using it;; or for whether it serves any particular purpose or works at all,;; unless he says so in writing.  Refer to the GNU Emacs General Public;; License for full details.;; Everyone is granted permission to copy, modify and redistribute;; this code, but only under the conditions described in the;; GNU Emacs General Public License.   A copy of this license is;; supposed to have been given to you along with GNU Emacs so you;; can know your rights and responsibilities.  It should be in a;; file named COPYING.  Among other things, the copyright notice;; and this notice must be preserved on all copies.;; To enter perl-mode automatically, add (autoload 'perl-mode "perl-mode");; to your .emacs file and change the first line of your perl script to:;; #!/usr/bin/perl --	 # -*-Perl-*-;; With argments to perl:;; #!/usr/bin/perl -P-	 # -*-Perl-*-;; To handle files included with do 'filename.pl';, add something like;; (setq auto-mode-alist (append (list (cons "\\.pl$" 'perl-mode));;                               auto-mode-alist));; to your .emacs file; otherwise the .pl suffix defaults to prolog-mode.;; This code is based on the 18.53 version c-mode.el, with extensive;; rewriting.  Most of the features of c-mode survived intact.;; I added a new feature which adds functionality to TAB; it is controlled;; by the variable perl-tab-to-comment.  With it enabled, TAB does the;; first thing it can from the following list:  change the indentation;;; move past leading white space; delete an empty comment; reindent a;; comment; move to end of line; create an empty comment; tell you that;; the line ends in a quoted string, or has a # which should be a \#.;; If your machine is slow, you may want to remove some of the bindings;; to electric-perl-terminator.  I changed the indenting defaults to be;; what Larry Wall uses in perl/lib, but left in all the options.;; I also tuned a few things:  comments and labels starting in column;; zero are left there by indent-perl-exp; perl-beginning-of-function;; goes back to the first open brace/paren in column zero, the open brace;; in 'sub ... {', or the equal sign in 'format ... ='; indent-perl-exp;; (meta-^q) indents from the current line through the close of the next;; brace/paren, so you don't need to start exactly at a brace or paren.;; It may be good style to put a set of redundant braces around your;; main program.  This will let you reindent it with meta-^q.;; Known problems (these are all caused by limitations in the elisp;; parsing routine (parse-partial-sexp), which was not designed for such;; a rich language; writing a more suitable parser would be a big job):;; 1)  Regular expression delimitors do not act as quotes, so special;;       characters such as `'"#:;[](){} may need to be backslashed;;       in regular expressions and in both parts of s/// and tr///.;; 2)  The globbing syntax <pattern> is not recognized, so special;;       characters in the pattern string must be backslashed.;; 3)  The q, qq, and << quoting operators are not recognized; see below.;; 4)  \ (backslash) always quotes the next character, so '\' is;;       treated as the start of a string.  Use "\\" as a work-around.;; 5)  To make variables such a $' and $#array work, perl-mode treats;;       $ just like backslash, so '$' is the same as problem 5.;; 6)  Unfortunately, treating $ like \ makes ${var} be treated as an;;       unmatched }.  See below.;; 7)  When ' (quote) is used as a package name separator, perl-mode;;       doesn't understand, and thinks it is seeing a quoted string.;; Here are some ugly tricks to bypass some of these problems:  the perl;; expression /`/ (that's a back-tick) usually evaluates harmlessly,;; but will trick perl-mode into starting a quoted string, which;; can be ended with another /`/.  Assuming you have no embedded;; back-ticks, this can used to help solve problem 3:;;;;     /`/; $ugly = q?"'$?; /`/;;;;; To solve problem 6, add a /{/; before each use of ${var}:;;     /{/; while (<${glob_me}>) ...;;;; Problem 7 is even worse, but this 'fix' does work :-(;;     $DB'stop#';;         [$DB'line#';;          ] =~ s/;9$//;(defvar perl-mode-abbrev-table nil  "Abbrev table in use in perl-mode buffers.")(define-abbrev-table 'perl-mode-abbrev-table ())(defvar perl-mode-map ()  "Keymap used in Perl mode.")(if perl-mode-map    ()  (setq perl-mode-map (make-sparse-keymap))  (define-key perl-mode-map "{" 'electric-perl-terminator)  (define-key perl-mode-map "}" 'electric-perl-terminator)  (define-key perl-mode-map ";" 'electric-perl-terminator)  (define-key perl-mode-map ":" 'electric-perl-terminator)  (define-key perl-mode-map "\e\C-a" 'perl-beginning-of-function)  (define-key perl-mode-map "\e\C-e" 'perl-end-of-function)  (define-key perl-mode-map "\e\C-h" 'mark-perl-function)  (define-key perl-mode-map "\e\C-q" 'indent-perl-exp)  (define-key perl-mode-map "\177" 'backward-delete-char-untabify)  (define-key perl-mode-map "\t" 'perl-indent-command))(autoload 'c-macro-expand "cmacexp"  "Display the result of expanding all C macros occurring in the region.The expansion is entirely correct because it uses the C preprocessor."  t)(defvar perl-mode-syntax-table nil  "Syntax table in use in perl-mode buffers.")(if perl-mode-syntax-table    ()  (setq perl-mode-syntax-table (make-syntax-table (standard-syntax-table)))  (modify-syntax-entry ?\n ">" perl-mode-syntax-table)  (modify-syntax-entry ?# "<" perl-mode-syntax-table)  (modify-syntax-entry ?$ "/" perl-mode-syntax-table)  (modify-syntax-entry ?% "." perl-mode-syntax-table)  (modify-syntax-entry ?& "." perl-mode-syntax-table)  (modify-syntax-entry ?\' "\"" perl-mode-syntax-table)  (modify-syntax-entry ?* "." perl-mode-syntax-table)  (modify-syntax-entry ?+ "." perl-mode-syntax-table)  (modify-syntax-entry ?- "." perl-mode-syntax-table)  (modify-syntax-entry ?/ "." perl-mode-syntax-table)  (modify-syntax-entry ?< "." perl-mode-syntax-table)  (modify-syntax-entry ?= "." perl-mode-syntax-table)  (modify-syntax-entry ?> "." perl-mode-syntax-table)  (modify-syntax-entry ?\\ "\\" perl-mode-syntax-table)  (modify-syntax-entry ?` "\"" perl-mode-syntax-table)  (modify-syntax-entry ?| "." perl-mode-syntax-table))(defconst perl-indent-level 4  "*Indentation of Perl statements with respect to containing block.")(defconst perl-continued-statement-offset 4  "*Extra indent for lines not starting new statements.")(defconst perl-continued-brace-offset -4  "*Extra indent for substatements that start with open-braces.This is in addition to perl-continued-statement-offset.")(defconst perl-brace-offset 0  "*Extra indentation for braces, compared with other text in same context.")(defconst perl-brace-imaginary-offset 0  "*Imagined indentation of an open brace that actually follows a statement.")(defconst perl-label-offset -2  "*Offset of Perl label lines relative to usual indentation.")(defconst perl-tab-always-indent t  "*Non-nil means TAB in Perl mode should always indent the current line,regardless of where in the line point is when the TAB command is used.")(defconst perl-tab-to-comment t  "*Non-nil means that for lines which don't need indenting, TAB willeither indent an existing comment, move to end-of-line, or if at end-of-linealready, create a new comment.")(defconst perl-nochange ";?#\\|\f\\|\\s(\\|\\(\\w\\|\\s_\\)+:"  "*Lines starting with this regular expression will not be auto-indented.")(defun perl-mode ()  "Major mode for editing Perl code.Expression and list commands understand all Perl brackets.Tab indents for Perl code.Comments are delimited with # ... \\n.Paragraphs are separated by blank lines only.Delete converts tabs to spaces as it moves back.\\{perl-mode-map}Variables controlling indentation style: perl-tab-always-indent    Non-nil means TAB in Perl mode should always indent the current line,    regardless of where in the line point is when the TAB command is used. perl-tab-to-comment    Non-nil means that for lines which don't need indenting, TAB will    either delete an empty comment, indent an existing comment, move     to end-of-line, or if at end-of-line already, create a new comment. perl-nochange    Lines starting with this regular expression will not be auto-indented. perl-indent-level    Indentation of Perl statements within surrounding block.    The surrounding block's indentation is the indentation    of the line on which the open-brace appears. perl-continued-statement-offset    Extra indentation given to a substatement, such as the    then-clause of an if or body of a while. perl-continued-brace-offset    Extra indentation given to a brace that starts a substatement.    This is in addition to perl-continued-statement-offset. perl-brace-offset    Extra indentation for line if it starts with an open brace. perl-brace-imaginary-offset    An open brace following other text is treated as if it were    this far to the right of the start of its line. perl-label-offset    Extra indentation for line that is a label.Various indentation styles:       K&R  BSD  BLK  GNU  LW  perl-indent-level                5    8    0    2    4  perl-continued-statement-offset  5    8    4    2    4  perl-continued-brace-offset      0    0    0    0   -4  perl-brace-offset               -5   -8    0    0    0  perl-brace-imaginary-offset      0    0    4    0    0  perl-label-offset               -5   -8   -2   -2   -2Turning on Perl mode calls the value of the variable perl-mode-hook with no args, if that value is non-nil."  (interactive)  (kill-all-local-variables)  (use-local-map perl-mode-map)  (setq major-mode 'perl-mode)  (setq mode-name "Perl")  (setq local-abbrev-table perl-mode-abbrev-table)  (set-syntax-table perl-mode-syntax-table)  (make-local-variable 'paragraph-start)  (setq paragraph-start (concat "^$\\|" page-delimiter))  (make-local-variable 'paragraph-separate)  (setq paragraph-separate paragraph-start)  (make-local-variable 'paragraph-ignore-fill-prefix)  (setq paragraph-ignore-fill-prefix t)  (make-local-variable 'indent-line-function)  (setq indent-line-function 'perl-indent-line)  (make-local-variable 'require-final-newline)  (setq require-final-newline t)  (make-local-variable 'comment-start)  (setq comment-start "# ")  (make-local-variable 'comment-end)  (setq comment-end "")  (make-local-variable 'comment-column)  (setq comment-column 32)  (make-local-variable 'comment-start-skip)  (setq comment-start-skip "\\(^\\|\\s-\\);?#+ *")  (make-local-variable 'comment-indent-hook)  (setq comment-indent-hook 'perl-comment-indent)  (make-local-variable 'parse-sexp-ignore-comments)  (setq parse-sexp-ignore-comments nil)  (run-hooks 'perl-mode-hook));; This is used by indent-for-comment;; to decide how much to indent a comment in Perl code;; based on its context.(defun perl-comment-indent ()  (if (and (bolp) (not (eolp)))      0					;Existing comment at bol stays there.    (save-excursion      (skip-chars-backward " \t")      (max (1+ (current-column))	;Else indent at comment column	   comment-column))))		; except leave at least one space.(defun electric-perl-terminator (arg)  "Insert character.  If at end-of-line, and not in a comment or a quote,correct the line's indentation."  (interactive "P")  (let ((insertpos (point)))    (and (not arg)			; decide whether to indent	 (eolp)	 (save-excursion	   (beginning-of-line)	   (and (not			; eliminate comments quickly		 (re-search-forward comment-start-skip insertpos t)) 		(or (/= last-command-char ?:)		    ;; Colon is special only after a label ....		    (looking-at "\\s-*\\(\\w\\|\\s_\\)+$"))		(let ((pps (parse-partial-sexp 			    (perl-beginning-of-function) insertpos)))		  (not (or (nth 3 pps) (nth 4 pps) (nth 5 pps))))))	 (progn				; must insert, indent, delete	   (insert-char last-command-char 1)	   (perl-indent-line)	   (delete-char -1))))  (self-insert-command (prefix-numeric-value arg)));; not used anymore, but may be useful someday:;;(defun perl-inside-parens-p ();;  (condition-case ();;      (save-excursion;;	(save-restriction;;	  (narrow-to-region (point);;			    (perl-beginning-of-function));;	  (goto-char (point-max));;	  (= (char-after (or (scan-lists (point) -1 1) (point-min))) ?\()));;    (error nil)))(defun perl-indent-command (&optional arg)  "Indent current line as Perl code, or optionally, insert a tab character.With an argument, indent the current line, regardless of other options.If perl-tab-always-indent is nil and point is not in the indentationarea at the beginning of the line, simply insert a tab.Otherwise, indent the current line.  If point was within the indentationarea it is moved to the end of the indentation area.  If the line wasalready indented properly and point was not within the indentation area,and if perl-tab-to-comment is non-nil (the default), then do the firstpossible action from the following list:  1) delete an empty comment  2) move forward to start of comment, indenting if necessary  3) move forward to end of line  4) create an empty comment  5) move backward to start of comment, indenting if necessary."  (interactive "P")  (if arg				; If arg, just indent this line      (perl-indent-line "\f")    (if (and (not perl-tab-always-indent)	     (<= (current-column) (current-indentation)))	(insert-tab)      (let (bof lsexp delta (oldpnt (point)))	(beginning-of-line)