Interpret-Facing names a function, with lambda list (FACING):
Given a FACING string, return an angle in radians.
This supports a string that is a floating-point number of radians that can be parsed by ORG.MAPCAR.PARSE-NUMBER::PARSE-NUMBER (not in this manual) or one of the cardinal eight directions as a string: N NE E SE S SW W NW.
Facing directions used to be only the cardinal directions; now, an arbitrary rotation in radians is possible.
TODO: Throw a 400-type exception when junk is passed in.
Defined in file src/infinity/new-commands-20.lisp.