terex is the new regular expression engine now and replaces PCRE (GRegex)

* terex is based on Henry Spencer's regular expression engine for Tcl.
  It is a hybrid NFA/DFA design which has better worst-time runtimes than
  the backtracking PCRE. Memory usage is also limited and can no longer
  increase catastrophically.
* It should no longer be possible to crash SciTECO with pathological
  searches.
* Since it reliably supports partial matches (REG_EXPECT) we can
  now enable the new backwards-search algorithm by default.
  This used to be broken because of a glib bug, which I already
  fixed. It would however take a long time until this ends up
  on the majority of glib installations.
* Regexp executions can still be quite slow if you are looking
  for a pattern at the end of a huge file, which can hang the editor,
  but this can now at least theoretically be solved by adding
  hooks into terex to poll for interruptions.
* We can now also get rid of a TECO-pattern to regexp translation
  step by directly generating terex tokens (TODO).
* Performance-wise terex appears to be slower than PCRE for simple
  forward searches even when linking everything with optimzations (FIXME).
* Having a stand-alone regular expression engine is also a huge
  step in getting rid of glib.

See also: https://git.fmsbw.de/terex/about/

1 files changed, 2 insertions, 1 deletions

diff --git a/Makefile.am b/Makefile.am
index 8284bc1..e956878 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -5,7 +5,8 @@ ACLOCAL_AMFLAGS = -I m4
 if REPLACE_MALLOC
 MAYBE_DLMALLOC = contrib/dlmalloc
 endif
-SUBDIRS = lib $(MAYBE_DLMALLOC) contrib/rb3ptr src doc tests
+SUBDIRS = lib $(MAYBE_DLMALLOC) contrib/rb3ptr contrib/terex \
+          src doc tests
 
 dist_scitecodata_DATA = fallback.teco_ini