see http://www.lispworks.com/documentation/HyperSpec/Body/22_cca.htm

(format t "~,5f" 1) errors with "The value of MEZZANO.FORMAT::PADCHAR is 5, which is not of type CHARACTER." which would be correct for ~,5d but not ~,5f.

(format t "~,5f" 1.0) prints 1.0 instead of 1.00000

(format t "~15,5f" 1.0) prints 1.0 instead of

        1.0000

(format t "~15,5,,,'+f" 1) errors with Too Many Parameters instead of printing ++++++++1.00000