(perl-font-lock-syntactic-keywords): New var, to recognize ${ $' and PODs.

(perl-font-lock-syntactic-face-function): New function.
(perl-mode): Use them.
(perl-continuation-line-p): New function, from perl-calculate-indent.
(perl-calculate-indent): Use it, to properly handle continuation
lines of continuation lines.

2 files changed, 60 insertions, 23 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index f69a26bec8b..1fc30e7bf36 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,13 @@
+2001-06-10  Stefan Monnier  <monnier@cs.yale.edu>
+
+        * progmodes/perl-mode.el (perl-font-lock-syntactic-keywords):
+        New var, to recognize ${ $' and PODs.
+        (perl-font-lock-syntactic-face-function): New function.
+        (perl-mode): Use them.
+        (perl-continuation-line-p): New function, from perl-calculate-indent.
+        (perl-calculate-indent): Use it, to properly handle continuation
+        lines of continuation lines.
+
 2001-06-10  Eli Zaretskii  <eliz@is.elta.co.il>
 
         * server.el (server-process, server-buffer-clients): Doc fix.
diff --git a/lisp/progmodes/perl-mode.el b/lisp/progmodes/perl-mode.el
index 98d2035112a..33ff6364390 100644
--- a/lisp/progmodes/perl-mode.el
+++ b/lisp/progmodes/perl-mode.el
@@ -72,14 +72,16 @@
 ;; 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 '$' work correctly, $' is not recognized as a variable.
+;;     Use "$'" or $POSTMATCH instead.
+;; 7)  When ' (quote) is used as a package name separator, perl-mode
+;;       doesn't understand, and thinks it is seeing a quoted string.
+;;
+;; If you don't use font-lock, additional problems will appear:
 ;; 5)  To make variables such a $' and $#array work, perl-mode treats
-;;       $ just like backslash, so '$' is the same as problem 5.
+;;       $ just like backslash, so '$' is not treated correctly.
 ;; 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,
@@ -116,7 +118,7 @@
     (define-key map "\177" 'backward-delete-char-untabify)
     (define-key map "\t" 'perl-indent-command)
     map)
-  "Keymap used in `perl-mode'.")
+  "Keymap used in Perl mode.")
 
 (autoload 'c-macro-expand "cmacexp"
   "Display the result of expanding all C macros occurring in the region.
@@ -211,6 +213,17 @@ The expansion is entirely correct because it uses the C preprocessor."
 (defvar perl-font-lock-keywords perl-font-lock-keywords-1
   "Default expressions to highlight in Perl mode.")
 
+(defvar perl-font-lock-syntactic-keywords
+  ;; Turn POD into b-style comments
+  '(("^\\(=\\)\\(head1\\|pod\\)\\([ \t]\\|$\\)" (1 "< b"))
+    ("^=cut[ \t]*\\(\n\\)" (1 "> b"))
+    ;; Catch ${ so that ${var} doesn't screw up indentation.
+    ("\\(\\$\\)[{']" (1 "."))))
+
+(defun perl-font-lock-syntactic-face-function (state)
+  (if (nth 3 state)
+      font-lock-string-face
+    (if (nth 7 state) font-lock-doc-face font-lock-comment-face)))
 
 (defcustom perl-indent-level 4
   "*Indentation of Perl statements with respect to containing block."
@@ -327,11 +340,15 @@ Turning on Perl mode runs the normal hook `perl-mode-hook'."
   (make-local-variable 'parse-sexp-ignore-comments)
   (setq parse-sexp-ignore-comments t)
   ;; Tell font-lock.el how to handle Perl.
-  (make-local-variable 'font-lock-defaults)
   (setq font-lock-defaults '((perl-font-lock-keywords
                               perl-font-lock-keywords-1
                               perl-font-lock-keywords-2)
-                             nil nil ((?\_ . "w"))))
+                             nil nil ((?\_ . "w")) nil
+                             (font-lock-syntactic-keywords
+                              . perl-font-lock-syntactic-keywords)
+                             (font-lock-syntactic-face-function
+                              . perl-font-lock-syntactic-face-function)
+                             (parse-sexp-lookup-properties . t)))
   ;; Tell imenu how to handle Perl.
   (make-local-variable 'imenu-generic-expression)
   (setq imenu-generic-expression perl-imenu-generic-expression)
@@ -480,6 +497,24 @@ changed by, or (parse-state) if line starts in a quoted string."
         (goto-char (- (point-max) pos)))
     shift-amt))
 
+(defun perl-continuation-line-p (limit)
+  "Move to end of previous line and return non-nil if continued."
+  ;; Statement level.  Is it a continuation or a new statement?
+  ;; Find previous non-comment character.
+  (perl-backward-to-noncomment)
+  ;; Back up over label lines, since they don't
+  ;; affect whether our line is a continuation.
+  (while (or (eq (preceding-char) ?\,)
+             (and (eq (preceding-char) ?:)
+                  (memq (char-syntax (char-after (- (point) 2)))
+                        '(?w ?_))))
+    (if (eq (preceding-char) ?\,)
+        (perl-backward-to-start-of-continued-exp limit)
+      (beginning-of-line))
+    (perl-backward-to-noncomment))
+  ;; Now we get the answer.
+  (not (memq (preceding-char) '(?\; ?\} ?\{))))
+
 (defun perl-calculate-indent (&optional parse-start)
   "Return appropriate indentation for current line as Perl code.
 In usual case returns an integer: the column to indent to.
@@ -528,26 +563,18 @@ Returns (parse-state) if line starts inside a string."
              (current-column))
             (t
              ;; Statement level.  Is it a continuation or a new statement?
-             ;; Find previous non-comment character.
-             (perl-backward-to-noncomment)
-             ;; Back up over label lines, since they don't
-             ;; affect whether our line is a continuation.
-             (while (or (eq (preceding-char) ?\,)
-                        (and (eq (preceding-char) ?:)
-                             (memq (char-syntax (char-after (- (point) 2)))
-                                   '(?w ?_))))
-               (if (eq (preceding-char) ?\,)
-                   (perl-backward-to-start-of-continued-exp containing-sexp)
-                 (beginning-of-line))
-               (perl-backward-to-noncomment))
-             ;; Now we get the answer.
-             (if (not (memq (preceding-char) '(?\; ?\} ?\{)))
+             (if (perl-continuation-line-p containing-sexp)
                  ;; This line is continuation of preceding line's statement;
                  ;; indent  perl-continued-statement-offset  more than the
                  ;; previous line of the statement.
                  (progn
                    (perl-backward-to-start-of-continued-exp containing-sexp)
-                   (+ perl-continued-statement-offset (current-column)
+                   (+ (if (save-excursion
+                            (perl-continuation-line-p containing-sexp))
+                          ;; If the continued line is itself a continuation
+                          ;; line, then align, otherwise add an offset.
+                          0 perl-continued-statement-offset)
+                      (current-column)
                       (if (save-excursion (goto-char indent-point)
                                           (looking-at "[ \t]*{"))
                           perl-continued-brace-offset 0)))