# NAME

Math::Ryu - perl interface to Ryu (float-to-string conversion).

# DEPENDENCIES

``````   This module uses the Ryu C implementation,  which is included with
Ryu code - but, should you wish to grab it, it's available at:
https://github.com/ulfjack/ryu/tree/master/ryu``````

# DESCRIPTION

``````   Convert an NV to a decimal string, such that no information is
lost, yet keeping the string as short as possible.

NOTE:
NVs whose size is greater than 8 bytes are not currently catered for.``````

# SYNOPSIS

``````   use Math::Ryu qw(:all);

my \$str = d2s(0.1);
print \$str;           # 1E-1

\$str = d2s(1.4 / 10);
print \$str;           # 1.3999999999999999E-1

\$str = d2s(sqrt 2);
print \$str;           # 1.4142135623730951E0

# Also do the reverse of s2d()
my \$d = s2d('1E-1');
printf "%.17g\n", \$d; # 0.10000000000000001``````

# FUNCTIONS

``````   \$nv = s2d(\$str);
Converts the string (\$str) to a vloating point value (\$nv)
and return \$nv.

\$str = d2s(\$nv);
\$nv holds a floating point numeric value.
\$str is a string in floating point format, that accurately
and succinctly represents the value held by \$nv.
\$str, when correctly assigned back to a perl number, will
always be equivalent to \$nv.
This in stark contrast to perl's interpolation which does not
guarantee that the condition ("\$nv" == \$nv) is true, even for
non-nan values of \$nv. (Eg if \$nv is sqrt 2.0 or 1.4/10 .)
Also, \$str will contain as few digits as possible, without
compromising that accuracy.

\$str = d2fixed(\$nv, \$digits);
\$str is a \$digits-decimal fixed point representation of \$nv.
For example, d2sfixed(1 / 10000, 6) returns '0.000100'.

\$str = d2exp(\$nv, \$digits);
\$str is a \$digits-decimal floating point representation of \$nv.
For example, d2exp(1 / 10000, 6) returns '1.000000e-04'.

\$str = d2s_buffered(\$nv);                       # Not very useful
Returns the same as d2s(\$nv).

(\$str, \$len) = d2s_buffered_n(\$nv);             # Not very useful
\$str is the same as returned by d2s(\$nv).
\$len is length(\$str).

\$str = d2fixed_buffered(\$nv, \$digits);           # Not very useful
Returns the same as d2fixed(\$nv, \$digits).

(\$str, \$len) = d2fixed_buffered_n(\$nv, \$digits); # Not very useful
\$str is the same as returned by d2fixed(\$nv, \$digits).
\$len is length(\$str).

\$str = d2exp_buffered(\$nv, \$digits);             # Not very useful
Returns the same as d2exp(\$nv, \$digits).

(\$str, \$len) = d2exp_buffered_n(\$nv, \$digits);   # Not very useful
\$str is the same as returned by d2exp(\$nv, \$digits).
\$len is length(\$str).``````

# TODO

``    Cover larger precision NV types (ie long double and __float128)``

``````    This perl module is free software; you may redistribute it
and/or modify it under the same terms as Perl itself.
However, the ".c" and ".h" files that ship with this distro
are Copyright 2018 Ulf Adams, and can only be used under the
the terms of version 2.0 the Apache License, or of version 1.0
``    Sisyphus <sisyphus at(@) cpan dot (.) org>``