2008/8/1 Tomi Belan wrote as "Limited regex support in newlib cripples
syntax highlighting in nano"
Cygwin regex.h implementation doesn't support some special sequences,
for example \< (beginning of word), \> (end of word) and \b (word
boundary). This causes a usability bug with the nano editor, which
uses these sequences extensively in most of its syntax highlighting
rules.
Posix regex is much faster then perl-style pcre regex. Syntax
highlighter usually prefer fast over complete. So the term "crippled"
should be used with care.
See e.g. http://swtch.com/~rsc/regexp/regexp1.html - Regular
Expression Matching Can Be Simple And Fast (but is slow in Java, Perl,
PHP, Python, Ruby, ...) - which complains about the typical POSIX
spencer implementation also.