/// <summary>
/// Constructs a new span with a specific start and end location.
/// </summary>
/// <param name="start">The beginning of the span.</param>
/// <param name="end">The end of the span.</param>
public SourceSpan(SourceLocation start, SourceLocation end)
{
ValidateLocations(start, end);
this._start = start;
this._end = end;
}
/// <summary>
/// Compares two specified location values.
/// </summary>
/// <param name="left">One location to compare.</param>
/// <param name="right">The other location to compare.</param>
/// <returns>0 if the locations are equal, -1 if the left one is less than the right one, 1 otherwise.</returns>
public static int Compare(SourceLocation left, SourceLocation right)
{
if (left < right) return -1;
if (right > left) return 1;
return 0;
}
private static void ValidateLocations(SourceLocation start, SourceLocation end)
{
if (start.IsValid && end.IsValid) {
if (start > end) {
throw new ArgumentException("Start and End must be well ordered");
}
} else {
if (start.IsValid || end.IsValid) {
throw new ArgumentException("Start and End must both be valid or both invalid");
}
}
}