Re: Regex parenthesis handling bug

[Thien-Thi Nguyen]

   From: Rob Browning <address@hidden>
   Date: Wed, 24 Oct 2001 18:20:27 -0500

   we should support some way for detecting what's available so that you
   can write conditional code, or at least ask for what you specifically
   need and have things fail otherwise.

boot-9.scm supports `provided?' as well as a module system.  a previous
version of `provided?' is semi-supported based on an env var.

thi