method

to_r

ruby latest stable - Class: Float

to_r()

public

Returns the value as a rational.

2.0.to_r    #=> (2/1)
2.5.to_r    #=> (5/2)
-0.75.to_r  #=> (-3/4)
0.0.to_r    #=> (0/1)
0.3.to_r    #=> (5404319552844595/18014398509481984)

NOTE: 0.3.to_r isn’t the same as “0.3”.to_r. The latter is equivalent to “3/10”.to_r, but the former isn’t so.

0.3.to_r   == 3/10r  #=> false
"0.3".to_r == 3/10r  #=> true

See also Float#rationalize.

static VALUE
float_to_r(VALUE self)
{
    VALUE f, n;

    float_decode_internal(self, &f, &n);
#if FLT_RADIX == 2
    {
        long ln = FIX2LONG(n);

        if (ln == 0)
            return rb_rational_new1(f);
        if (ln > 0)
            return rb_rational_new1(rb_int_lshift(f, n));
        ln = -ln;
        return rb_rational_new2(f, rb_int_lshift(ONE, INT2FIX(ln)));
    }
#else
    f = rb_int_mul(f, rb_int_pow(INT2FIX(FLT_RADIX), n));
    if (RB_TYPE_P(f, T_RATIONAL))
        return f;
    return rb_rational_new1(f);
#endif
}

to_r

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