method

**

v2_2_9 - Show latest stable - 0 notes - Class: Rational

**(p1) public

Performs exponentiation.

Rational(2)    ** Rational(3)    #=> (8/1)
Rational(10)   ** -2             #=> (1/100)
Rational(10)   ** -2.0           #=> 0.01
Rational(-4)   ** Rational(1,2)  #=> (1.2246063538223773e-16+2.0i)
Rational(1, 2) ** 0              #=> (1/1)
Rational(1, 2) ** 0.0            #=> 1.0

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static VALUE
nurat_expt(VALUE self, VALUE other)
{
    if (k_numeric_p(other) && k_exact_zero_p(other))
        return f_rational_new_bang1(CLASS_OF(self), ONE);

    if (k_rational_p(other)) {
        get_dat1(other);

        if (f_one_p(dat->den))
            other = dat->num; /* c14n */
    }

    /* Deal with special cases of 0**n and 1**n */
    if (k_numeric_p(other) && k_exact_p(other)) {
        get_dat1(self);
        if (f_one_p(dat->den)) {
            if (f_one_p(dat->num)) {
                return f_rational_new_bang1(CLASS_OF(self), ONE);
            }
            else if (f_minus_one_p(dat->num) && k_integer_p(other)) {
                return f_rational_new_bang1(CLASS_OF(self), INT2FIX(f_odd_p(other) ? -1 : 1));
            }
            else if (f_zero_p(dat->num)) {
                if (FIX2INT(f_cmp(other, ZERO)) == -1) {
                    rb_raise_zerodiv();
                }
                else {
                    return f_rational_new_bang1(CLASS_OF(self), ZERO);
                }
            }
        }
    }

    /* General case */
    if (RB_TYPE_P(other, T_FIXNUM)) {
        {
            VALUE num, den;

            get_dat1(self);

            switch (FIX2INT(f_cmp(other, ZERO))) {
              case 1:
                num = f_expt(dat->num, other);
                den = f_expt(dat->den, other);
                break;
              case -1:
                num = f_expt(dat->den, f_negate(other));
                den = f_expt(dat->num, f_negate(other));
                break;
              default:
                num = ONE;
                den = ONE;
                break;
            }
            if (RB_FLOAT_TYPE_P(num)) { /* infinity due to overflow */
                if (RB_FLOAT_TYPE_P(den)) return DBL2NUM(NAN);
                return num;
            }
            return f_rational_new2(CLASS_OF(self), num, den);
        }
    }
    else if (RB_TYPE_P(other, T_BIGNUM)) {
        rb_warn("in a**b, b may be too big");
        return f_expt(f_to_f(self), other);
    }
    else if (RB_TYPE_P(other, T_FLOAT) || RB_TYPE_P(other, T_RATIONAL)) {
        return f_expt(f_to_f(self), other);
    }
    else {
        return rb_num_coerce_bin(self, other, id_expt);
    }
}

**

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