/// <summary>
/// Called by ParseMetric(String str). Strips the assign()s until it find the value
/// </summary>
/// <param name="name">name of the metric (e.g., "default" or "euclidean")</param>
/// <returns>The value for X . Y metric</returns>
private static double ParseMetric(Specification S, string name, Object O, string str)
{
// first check if 'O' could be the final value of the metric specification
G25.rsep.FunctionApplication FA = O as G25.rsep.FunctionApplication;
if ((FA == null) || (FA.FunctionName == "negate") || (FA.FunctionName == "nop"))
{
return ParseMetricValue(S, O, str);
}
// This FA should be of the form X.Y=value
// First argument must be a XdotY function application, and the function name should be "assign"
G25.rsep.FunctionApplication XdotY = FA.Arguments[0] as G25.rsep.FunctionApplication;
if ((FA.NbArguments != 2) || (FA.FunctionName != "assign") ||
(XdotY == null) || (XdotY.NbArguments != 2) ||
(XdotY.FunctionName != "ip")) throw new G25.UserException("Invalid metric specification '" + str + "'");
// get value by recursing
double value = ParseMetric(S, name, FA.Arguments[1], str);
// get, check names of basis vectors
string basisVectorName1 = XdotY.Arguments[0] as String;
string basisVectorName2 = XdotY.Arguments[1] as String;
if ((basisVectorName1 == null) || (basisVectorName2 == null))
throw new G25.UserException("Invalid basis vector names in metric specification '" + str + "'");
int basisVectorIdx1 = S.BasisVectorNameToIndex(basisVectorName1);
int basisVectorIdx2 = S.BasisVectorNameToIndex(basisVectorName2);
S.SetMetric(name, basisVectorIdx1, basisVectorIdx2, value);
return value;
}