Re: shell mode syntax higlighting problem with here documents

[Nicholas Sushkin <nsushkin@openfinance.com>]

Stefan, I am trying to test in Emacs 21.3.1 your revision 1.169, but getting 
"Invalid escape character syntax" in the statement below. Is my emacs too 
old or it's really a bug? 

Thanks

(defvar sh-skeleton-pair-default-alist '((?( _ ?)) (?\))
          (?[ ?\s _ ?\s ?]) (?\])
          (?{ _ ?}) (?\}))
  "Value to use for `skeleton-pair-default-alist' in Shell-Script mode.")




On Wednesday 19 October 2005 23:48, Stefan Monnier wrote: 

> > #!/bin/bash
> > cat << EOF | \
> >     tee -a bug.txt
> >
> > This is a test case for a bug in bash shell mode text highlighting
> > EOF
>
> If people who hack on SH scripts with lots of heredoc thingies could try
> the patch below, it would help.  It's relative to the Emacs-CVS code. It
> seems "safe" and appears to do the right thing with the above example,
> but I'd like to get some positive feedback before installing it,
>
>
>         Stefan
>
>
> --- orig/lisp/progmodes/sh-script.el
> +++ mod/lisp/progmodes/sh-script.el
> @@ -869,7 +869,18 @@
>  (defconst sh-st-symbol (string-to-syntax "_"))
>  (defconst sh-here-doc-syntax (string-to-syntax "|")) ;; generic string
>
> -(defconst sh-here-doc-open-re
> "<<-?\\s-*\\\\?\\(\\(?:['\"][^'\"]+['\"]\\|\\sw\\)+\\).*\\(\n\\)")
> +(defconst sh-escaped-line-re
> +  (concat
> +   "\\(?:"
> +   ;; First the real regexp.
> +  
> "\\(?:.*[^\\\n]\\)?\\(?:\\(?:\\\\\\\\\\)*\\\\\n\\(?:.*[^\\\n]\\)?\\)*" + 
>  ;; Then a failsafe fallback: in case the search boundary prevents us
> from +   ;; finding the actual end of line.
> +   "\\|.*\\)"))
> +
> +(defconst sh-here-doc-open-re
> +  (concat "<<-?\\s-*\\\\?\\(\\(?:['\"][^'\"]+['\"]\\|\\sw\\)+\\)"
> +          sh-escaped-line-re "\\(\n\\)"))
>
>  (defvar sh-here-doc-markers nil)
>  (make-variable-buffer-local 'sh-here-doc-markers)
> @@ -883,7 +894,9 @@
>           ;; A rough regexp that should find the opening <<EOF back.
>  	 (sre (concat "<<\\(-?\\)\\s-*['\"\\]?"
>  		      ;; Use \s| to cheaply check it's an open-heredoc.
> -		      eof-re "['\"]?\\([ \t|;&)<>].*\\)?\\s|"))
> +		      eof-re "['\"]?\\([ \t|;&)<>]"
> +                      sh-escaped-line-re
> +                      "\\)?\\s|"))
>  	 ;; A regexp that will find other EOFs.
>  	 (ere (concat "^" (if indented "[ \t]*") eof-re "\n"))
>  	 (start (save-excursion
> @@ -922,7 +935,8 @@
>  START is the position of <<.
>  STRING is the actual word used as delimiter (f.ex. \"EOF\").
>  INDENTED is non-nil if the here document's content (and the EOF mark)
> can -be indented (i.e. a <<- was used rather than just <<)."
> +be indented (i.e. a <<- was used rather than just <<).
> +Point is at the beginning of the next line."
>    (unless (or (memq (char-before start) '(?< ?>))
>  	      (sh-in-comment-or-string start))
>      ;; We're looking at <<STRING, so we add "^STRING$" to the syntactic
> @@ -933,6 +947,20 @@
>  	(setq sh-here-doc-re
>  	      (concat sh-here-doc-open-re "\\|^\\([ \t]*\\)"
>  		      (regexp-opt sh-here-doc-markers t) "\\(\n\\)"))))
> +    (let ((ppss (save-excursion (syntax-ppss (1- (point))))))
> +      (if (nth 4 ppss)
> +          ;; The \n not only starts the heredoc but also closes a
> comment. +          ;; Let's close the comment just before the \n.
> +          (put-text-property (1- (point)) (point) 'syntax-table '(12)))
> ;">" +      (if (or (> (count-lines start (point)) 1) (nth 5 ppss))
> +          ;; If the sh-escaped-line-re part of sh-here-doc-re has
> matched +          ;; several lines, make sure we refontify them
> together. +          ;; Furthermore, if (nth 5 ppss) is non-nil (i.e. the
> \n is +          ;; escaped), it means we haven't actually found the
> right \n. +          ;; Don't bother fixing it now, but place a multiline
> property so +          ;; that when jit-lock-context-* refontifies the
> rest of the +          ;; buffer, it also refontifies the current line
> with it. +          (put-text-property start (point) 'font-lock-multiline
> t))) sh-here-doc-syntax))
>
>  (defun sh-font-lock-here-doc (limit)

-- 
Nicholas Sushkin, Senior Software Engineer
Open Finance, Chelsea Piers Pier 62 Suite 316, New York NY 10011
Tel +1 646 723 2790 Fax +1 646 723 2789 nsushkin@openfinance.com