define extensible boundary syntax
define extensible boundary syntax

The Unicode folks seem to want an extensible boundary syntax with \b,
but we've abandoned \b for boundary, so it's now <|x> for various
values of x.  (And <!|x> is the negation, so no need for <|X>.)
<?wb> is now <|w>.

prammer/specs,perl6/specs,perl6/specs,tokuhirom/specs,prammer/specs,tokuhirom/specs,prammer/specs,tokuhirom/specs