[sedachv]

> Also note that lack of hygiene is actually a useful feature - it allows macros to capture variables from code passed to it as well as the environment they expand it. Some cool stuff can be done that way (some uncool foot-shooting too, though).

Doug Hoyte's excellent book _Let Over Lambda_ has a lot of examples.

[TeMPOraL]

Oh yes. This book is very fun, in the "what on Earth did he just do here" kind of way.