/// <summary>
/// A Debian-like parsing of version numbers that encodes the
/// operation into the string. For example, "> 2.3.4" would be
/// true if the ExtendedVersion object was 2.3.5 but not 2.3.3 or 2.3.4.
///
/// The following operations are allowed:
/// "<", "<=", "=", ">", ">="
///
/// There may be any number of spaces between the op and the version.
/// </summary>
public bool Compare(string operation)
{
// Pull out the parts using substrings.
string op;
string ver;
if (operation.StartsWith(">="))
{
op = ">=";
ver = operation.Substring(2).Trim();
}
else if (operation.StartsWith("<="))
{
op = "<=";
ver = operation.Substring(2).Trim();
}
else if (operation.StartsWith("<"))
{
op = "<";
ver = operation.Substring(1).Trim();
}
else if (operation.StartsWith(">"))
{
op = ">";
ver = operation.Substring(1).Trim();
}
else if (operation.StartsWith("="))
{
op = "=";
ver = operation.Substring(1).Trim();
}
else
{
return(false);
}
// Check the op
var v = new ExtendedVersion(ver);
switch (op)
{
case "<":
return(this < v);
case "<=":
return(this <= v);
case "=":
return(this == v);
case ">":
return(this > v);
case ">=":
return(this >= v);
default:
throw new Exception("Cannot identify operation: " + op);
}
}
/// <summary>
/// Determines if the first is less than the second one. There are
/// some conditions where a version is neither less than or greater
/// than another version, specifcally with version parts that have
/// text in it.
/// </summary>
public static bool operator <(ExtendedVersion v1,
ExtendedVersion v2)
{
// Make sure v1 has the less parts, for simplicicity.
bool swapped = false;
if (v1.numerics.Length > v2.numerics.Length)
{
ExtendedVersion v3 = v2;
v2 = v1;
v1 = v3;
swapped = true;
}
// Go through the various parts
for (int i = 0;
i < v1.numerics.Length;
i++)
{
// Get the parts
int num1 = v1.numerics[i];
string str1 = v1.strings[i];
int num2 = v2.numerics[i];
string str2 = v2.strings[i];
// Make sure strings match. If they do not, then the versions
// will never match.
if (str1 != str2)
{
return(swapped);
}
// Compare the numbers. If num1 is less than num2, then the
// rest of the version will be less. If it is the reverse,
// return it.
if (num1 < num2)
{
return(!swapped);
}
if (num1 > num2)
{
return(swapped);
}
}
// We never got something that explicitly was less or invalid,
// so assume false (equals).
return(swapped);
}
