D.6 Use existing utility functions (don’t write your own)
Look carefully for existing utility functions before
re-implementation. Check the following places before implementation
of any utility:
- Run
(apropos "thing") in the repl.
- Search the
hyperspec
(with Emacs slime properly configured you can tab-complete to plumb
the existing definitions in the hyperspec). The hyperspec is a
reference, good for lookup and bad for browsing.
- Check the
Alexandria
and
Serapeum
packages for general utilities and the
UIOP package for
filesystem and OS utilities.
- Check the “GT” package (see Basic Utilities).