Actually, that works even if you don't change read-default-float-format. I think + should coerce single-floats to double-floats when appropriate, though.
CL-USER> (+ 1203981239.123d0 129381723987498237492138461293238947239847293848923)
==> 1.2938172398749823d50
CL-USER> (+ 1203981239.123f0 129381723987498237492138461293238947239847293848923)
debugger invoked on a SIMPLE-TYPE-ERROR ...
(note ...f0 vs ...d0)
Admittedly, this is not a problem I'd expect to encounter in real life, so I'm not losing much sleep over it. CL is weird and I accept that ;)
Admittedly, this is not a problem I'd expect to encounter in real life, so I'm not losing much sleep over it. CL is weird and I accept that ;)