Module Norn_float_text.Float_print
Floats to a number of digits, the same text on every system.
OCaml's Printf writes a float with the C library's printf, whose text differs between systems: under mingw-w64, msvcrt writes three exponent digits, keeps 17 digits and rounds from those, and rounds an exact tie away from zero. g and f lay out the digits Float_text computes from a float's exact decimal value, rounded once, to nearest, ties to even, as C's printf does where it is correctly rounded. A NaN is nan whatever its sign, and the infinities inf and -inf; a negative zero keeps its sign.
val g : int -> float -> stringg p x is x as C's %.*g writes it, with p significant digits, at least 1: positional for a decimal exponent from -4 to below p, otherwise with an exponent of at least two digits, without trailing zeros, as 135.562, 1e+16 and 1.5e-05 at six.
val f : int -> float -> stringf decimals x is x as C's %.*f writes it, with decimals digits after the point, at least 0: 0.12 for 0.125 at two.