1tre-config.h contains additional defines that their configure puts in
2config.h.
3
4We have remapped the POSIX entry points with a tre_ suffix: without
5it there was confusion with entry points in OS libraries on some OSes
6(e.g. macOS).
7
8alloca has been disabled: the declarations used do not work on
9Windows, and most likely not on FreeBSD.
10
11The way we compile it, TRE works internally in one of three modes
12
13STR_BYTE, using bytes
14STR_MBS , using wchar_t for matching, I/O in MBCS
15STR_WIDE, using wchar_t
16
17We've added interfaces tre_regcompb, tre_regncompb, tre_regexecb,
18tre_regnexecb and regaexecb to force STR_BYTE.  Unless forced, bytes
19are used in a single-byte locale and wchar_t in a MBCS.  We need to
20force for useBytes=TRUE, for support for UTF-8 encoded strings
21in a single-byte locale (principally on Windows) and when dealing with
22raw vectors. You do need to ensure that regcomp and regexec use the
23same type.
24
25The offsets in the regmatch_t structure are in characters for
26STR_WIDE, bytes for the other two modes.
27
28On Windows (MinGW?), iswctype is missing 'blank'.
29
30REG_LITERAL was not matching "" in some cases, hence a change at
31line 1652 of tre-parse.c.
32
33We fixed stack trampling in tre_tnfa_run_approx() and converted
34tre_ast_to_tnfa() from recursion to iteration over a TRE stack.
35
36We commented out in tre-match-approx.c
37
38/* These seem compiler/OS-specific, but unexplained
39On Linux the first is intended to be used only with GCC.
40#define __USE_STRING_INLINES
41#undef __NO_INLINE__
42*/
43
44since it failed on clang
45https://stat.ethz.ch/pipermail/r-devel/2010-February/056728.html
46
47Nov 2011: incorporated minor fixes from https://github.com/GerHobbelt/libtre
48(see https://laurikari.net/tre/website-issues-and-future-plans/#comments).
49
50Oct 2014: fixed R bug PR#16009 by copying the class member of a LITERAL
51in tre_copy_ast.
52
53Nov 2014: changed tre_version() to report this is a modified version.
54
55Apr 2020: incorporated a patch to tre-parse.c from
56https://github.com/laurikari/tre/issues/55
57