public static RubyNumeric intervalStepSize(
ThreadContext context,
IRubyObject from,
IRubyObject to,
IRubyObject step,
boolean excludeLast) {
Ruby runtime = context.runtime;
if (from instanceof RubyFixnum && to instanceof RubyFixnum && step instanceof RubyFixnum) {
long diff = ((RubyFixnum) step).getLongValue();
if (diff == 0) {
return RubyFloat.newFloat(runtime, Double.POSITIVE_INFINITY);
}
long delta = ((RubyFixnum) to).getLongValue() - ((RubyFixnum) from).getLongValue();
if (diff < 0) {
diff = -diff;
delta = -delta;
}
if (excludeLast) {
delta--;
}
if (delta < 0) {
return runtime.newFixnum(0);
}
long result = delta / diff;
return new RubyFixnum(runtime, result >= 0 ? result + 1 : 0);
} else if (from instanceof RubyFloat || to instanceof RubyFloat || step instanceof RubyFloat) {
double n =
floatStepSize(
from.convertToFloat().getDoubleValue(),
to.convertToFloat().getDoubleValue(),
step.convertToFloat().getDoubleValue(),
excludeLast);
if (Double.isInfinite(n)) {
return runtime.newFloat(n);
} else {
return runtime.newFloat(n).convertToInteger();
}
} else {
String cmpString = ">";
RubyFixnum zero = RubyFixnum.zero(runtime);
IRubyObject comparison = zero.coerceCmp(context, "<=>", step);
switch (RubyComparable.cmpint(context, comparison, step, zero)) {
case 0:
return RubyFloat.newFloat(runtime, Float.POSITIVE_INFINITY);
case 1:
cmpString = "<";
break;
}
if (from.callMethod(context, cmpString, to).isTrue()) {
return RubyFixnum.zero(runtime);
}
IRubyObject diff = to.callMethod(context, "-", from);
IRubyObject result = diff.callMethod(context, "div", step);
if (!excludeLast
|| from.callMethod(context, "+", result.callMethod(context, "*", step))
.callMethod(context, cmpString, to)
.isTrue()) {
result = result.callMethod(context, "+", RubyFixnum.newFixnum(runtime, 1));
}
return (RubyNumeric) result;
}
}
