public T To <T> () where T : struct
{
BaseTerm e = ChainEnd();
try
{
return((e is ValueTerm)
? (T)Convert.ChangeType(e.functor, typeof(T))
: e.Eval().To <T> ());
}
catch
{
if (e is NamedVariable)
{
IO.Error("Unable to convert unbound variable {0} to type {1}",
((NamedVariable)e).Name, typeof(T).UnderlyingSystemType.Name);
}
else if (e is Variable)
{
IO.Error("Unable to convert an unbound variable to type {0}",
typeof(T).UnderlyingSystemType.Name);
}
else if (e is ListTerm)
{
IO.Error("Unable to convert list {0} to type {1}",
e, typeof(T).UnderlyingSystemType.Name);
}
else
{
IO.Error("Unable to convert '{0}' to type {1}",
e.FunctorToString, typeof(T).UnderlyingSystemType.Name);
}
return(default(T)); // IO.Error throws error, but compiler insists on a return value
}
}