An Open Location Code library for Common Lisp.

Open Location Code is a location encoding system for addresses,
independent of street names and building numbers.

See <https://plus.codes>.


The methods requested by the Open Location Code specification
are implemented as follows:

encode (LATITUDE LONGITUDE)  ==>  FULL-CODE
     Convert a latitude and longitude into a 10 digit Open
     Location Code.

encode (LATITUDE LONGITUDE PRECISION)  ==>  FULL-CODE
     Convert a latitude and longitude into an arbitrary
     length Open Location Code.

decode (CODE)  ==>  CODE-AREA
     Decode an Open Location Code into, at a minimum, the
     latitude and longitude of the south-west corner and
     the area's height and width.

validp (CODE)  ==>  boolean
     Determine if a string is a valid sequence of Open
     Location Code characters.

fullp (CODE)  ==>  boolean
     Determine if a string is a valid full Open Location
     Code.

shortp (CODE)  ==>  boolean
     Determine if a string is a valid short Open Location
     Code.

shorten (FULL-CODE LATITUDE LONGITUDE)  ==>  SHORT-CODE
     Remove four or six digits from the front of an Open
     Location Code given a reference location.

recover (SHORT-CODE LATITUDE LONGITUDE)  ==>  FULL-CODE
     Recover a full Open Location Code from a short code
     and a reference location.

See <https://github.com/google/open-location-code/> for more
documentation and sample implementations.