Regular expression too big

[Greg Detre]

hello,

i sent this identical message via M-x report-bug, but just 
in case it didn't work, here it is in pure email form

many thanks,
  greg

p.s. emacs rocs


To: address@hidden
CC: address@hidden
Subject: Regular expression too big
--text follows this line--


Hello,

I'm writing a new mode for Emacs that involves a massive
regular expression, auto-generated from a list of files in
the directory. If the number of files is too large (c. 1500,
depending on the length of the filenames), then the regular
expression that gets built is too big, and Emacs flashes up
an error: Invalid regexp: "regular expression too big".

So it looks as though this is a known issue, and that the
solution was just to hardcode a ceiling on regexp size. This
is a showstopper for us. At the moment, the only workaround
that we can think of would be to chop the regexp into
multiple pieces, run them separately, and then somehow
combine the results. As you can imagine, this is going to be
much slower, and much much uglier.

Is there anything that can be done to extend the allowed
size of the regexp?

Many thanks,
   Greg Detre
   address@hidden




In GNU Emacs 22.0.50.1 (i486-pc-linux-gnu, GTK+ Version 2.10.3)
 of 2006-09-19 on rothera, modified by Debian
 (Debian emacs-snapshot package, version 1:20060915-1)
X server distributor `The X.Org Foundation', version 
11.0.70101000
configured using `configure  '--build' 'i486-linux-gnu' 
'--host' 'i486-linux-gnu' '--prefix=/usr' 
'--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' 
'--localstatedir=/var' '--infodir=/usr/share/info' 
'--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/22.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/22.0.50/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/22.0.50/leim' 
'--with-x=yes' '--with-x-toolkit=gtk' 
'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 
'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  partial-completion-mode: t
  pc-selection-mode: t
  delete-selection-mode: t
  show-paren-mode: t
  shell-dirtrack-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n
C-n C-n C-n C-n C-o C-j C-l C-g M-l u n i x SPC c u
r l <return> U n i x SPC c u r l <return> <return>
<up> <up> <S-left> <S-down> <S-left> C-M-2 C-S-z C-S-z
C-S-z <down> <down> <up> <up> U n i x SPC c u r l <return>
<return> <up> <up> <S-down> <S-left> C-M-1 <down> <right>
<C-return> <M-return> <help-echo> <help-echo> <help-echo>
<select-window> <select-window> <select-window> <select-window>
<help-echo> <select-window> <select-window> <M-return>
<select-window> M-x r e p o <tab> r t SPC e <tab>
<return>

Recent messages:
Error during redisplay: (invalid-regexp Regular expression 
too big) [10 times]
Mark set
and: Invalid regexp: "Regular expression too big"Error 
during redisplay: (invalid-regexp Regular expression too big)
Mark set
Wrote /home/greg/docs/freex/unix curl.freex
Added unix curl.freex to db
and: Invalid regexp: "Regular expression too big"Error 
during redisplay: (invalid-regexp Regular expression too big)
Mark set
and: Invalid regexp: "Regular expression too big"Error 
during redisplay: (invalid-regexp Regular expression too big)
Loading emacsbug...done

--


---
Greg Detre
cell: 617 642 3902
email: address@hidden
web: http://www.gregdetre.co.uk