Encode a signed
RealFloat according to
FPFormat and
optionally requested precision.
This corresponds to the
show{E,F,G}Float operations provided
by
base's
Numeric module.
NOTE: The functions in
base-4.12 changed the
serialisation in case of a
Just 0 precision; this version of
text still provides the serialisation as implemented in
base-4.11. The next major version of
text will
switch to the more correct
base-4.12 serialisation.