@JRubyMethod(name = "to_r")
public IRubyObject to_r(ThreadContext context) {
long[] exp = new long[1];
double f = frexp(value, exp);
f = ldexp(f, DBL_MANT_DIG);
long n = exp[0] - DBL_MANT_DIG;
Ruby runtime = context.runtime;
IRubyObject rf = RubyNumeric.dbl2num(runtime, f);
IRubyObject rn = RubyFixnum.newFixnum(runtime, n);
return f_mul(context, rf, f_expt(context, RubyFixnum.newFixnum(runtime, FLT_RADIX), rn));
}
/** float_rationalize */
@JRubyMethod(name = "rationalize", optional = 1)
public IRubyObject rationalize(ThreadContext context, IRubyObject[] args) {
if (f_negative_p(context, this))
return f_negate(context, ((RubyFloat) f_abs(context, this)).rationalize(context, args));
Ruby runtime = context.runtime;
RubyFixnum one = RubyFixnum.one(runtime);
RubyFixnum two = RubyFixnum.two(runtime);
IRubyObject eps, a, b;
if (args.length != 0) {
eps = f_abs(context, args[0]);
a = f_sub(context, this, eps);
b = f_add(context, this, eps);
} else {
long[] exp = new long[1];
double f = frexp(value, exp);
f = ldexp(f, DBL_MANT_DIG);
long n = exp[0] - DBL_MANT_DIG;
IRubyObject rf = RubyNumeric.dbl2num(runtime, f);
IRubyObject rn = RubyFixnum.newFixnum(runtime, n);
if (f_zero_p(context, rf) || !(f_negative_p(context, rn) || f_zero_p(context, rn)))
return RubyRational.newRationalRaw(runtime, f_lshift(context, rf, rn));
a =
RubyRational.newRationalRaw(
runtime,
f_sub(context, f_mul(context, two, rf), one),
f_lshift(context, one, f_sub(context, one, rn)));
b =
RubyRational.newRationalRaw(
runtime,
f_add(context, f_mul(context, two, rf), one),
f_lshift(context, one, f_sub(context, one, rn)));
}
if (invokedynamic(context, a, OP_EQUAL, b).isTrue()) return f_to_r(context, this);
IRubyObject[] ary = new IRubyObject[2];
ary[0] = a;
ary[1] = b;
IRubyObject[] ans = nurat_rationalize_internal(context, ary);
return RubyRational.newRationalRaw(runtime, ans[0], ans[1]);
}
