This site is a static rendering of the Trac instance that was used by R7RS-WG1 for its work on R7RS-small (PDF), which was ratified in 2013. For more information, see Home. For a version of this page that may be more recent, see CondExpandShinn in WG2's repo for R7RS-large.


2013-11-28 15:29:11

In the small language you can test library availability with:

(define-library (foo bar) ... (cond-expand ((library (scheme regexp)) ...) (else ...)))

but you might want to be sure that the regexp-unicode feature was available, like this:

(define-library (foo bar) ... (cond-expand ((library-provides (scheme regexp) regexp-unicode) ...) (else ...)))