Пример #1
0
  @JRubyMethod(name = "round", compat = CompatVersion.RUBY1_9)
  public IRubyObject round19(ThreadContext context, IRubyObject arg) {
    int ndigits = RubyNumeric.num2int(arg);
    if (ndigits > 0) return RubyKernel.new_float(this, this);
    if (ndigits == 0) return this;
    ndigits = -ndigits;
    Ruby runtime = context.getRuntime();
    if (ndigits < 0) throw runtime.newArgumentError("ndigits out of range");
    IRubyObject f = Numeric.int_pow(context, 10, ndigits);

    if (this instanceof RubyFixnum && f instanceof RubyFixnum) {
      long x = ((RubyFixnum) this).getLongValue();
      long y = ((RubyFixnum) f).getLongValue();
      boolean neg = x < 0;
      if (neg) x = -x;
      x = (x + y / 2) / y * y;
      if (neg) x = -x;
      return RubyFixnum.newFixnum(runtime, x);
    } else {
      IRubyObject h = f.callMethod(context, "/", RubyFixnum.two(runtime));
      IRubyObject r = callMethod(context, "%", f);
      IRubyObject n = callMethod(context, "-", r);
      if (!r.callMethod(context, "<", h).isTrue()) n = n.callMethod(context, "+", f);
      return n;
    }
  }
Пример #2
0
  @JRubyMethod(name = "round", compat = CompatVersion.RUBY1_9)
  public IRubyObject round19(ThreadContext context, IRubyObject arg) {
    int ndigits = RubyNumeric.num2int(arg);
    if (ndigits > 0) return RubyKernel.new_float(this, this);
    if (ndigits == 0) return this;
    Ruby runtime = context.runtime;

    long bytes = (this instanceof RubyFixnum) ? 8 : RubyFixnum.fix2long(callMethod("size"));
    /* If 10**N/2 > this, return 0 */
    /* We have log_256(10) > 0.415241 and log_256(1/2)=-0.125 */
    if (-0.415241 * ndigits - 0.125 > bytes) {
      return RubyFixnum.zero(runtime);
    }

    IRubyObject f = Numeric.int_pow(context, 10, -ndigits);

    if (this instanceof RubyFixnum && f instanceof RubyFixnum) {
      long x = ((RubyFixnum) this).getLongValue();
      long y = ((RubyFixnum) f).getLongValue();
      boolean neg = x < 0;
      if (neg) x = -x;
      x = (x + y / 2) / y * y;
      if (neg) x = -x;
      return RubyFixnum.newFixnum(runtime, x);
    } else if (f instanceof RubyFloat) {
      return RubyFixnum.zero(runtime);
    } else {
      IRubyObject h = f.callMethod(context, "/", RubyFixnum.two(runtime));
      IRubyObject r = callMethod(context, "%", f);
      IRubyObject n = callMethod(context, "-", r);
      String op = callMethod(context, "<", RubyFixnum.zero(runtime)).isTrue() ? "<=" : "<";
      if (!r.callMethod(context, op, h).isTrue()) n = n.callMethod(context, "+", f);
      return n;
    }
  }