hylang/hy — pull request #461 by algernon (2014-01-18 15:29:34+00:00)
Title: hy/core/macros.hy: Add an (if-not) macro

Sometimes it is better to start with the false condition, sometimes that
makes the code clearer. For that, the (if-not) macro, which simply
reverses the order of the condition blocks, can be of great use.

Signed-off-by: Gergely Nagy