Compares this object to another Comparable
Returns a value like a Comparator when comparing this to other.
That is, it returns a negative integer if this is ordered before other,
a positive integer if this is ordered after other,
and zero if this and other are ordered together.
The other argument must be a value that is comparable to this object.
Source
int compareTo(Comparable other) {
// For now, only allow compares to other intervals.
if (other is Interval) {
// Equality, less and greater tests.
if (this == other) return 0;
if (this < other) return -1;
if (this > other) return 1;
} else {
throw new ArgumentError('$other is not comparable to Interval.');
}
}