/// <summary>
/// Gets all constraint types for the given <paramref name="typeParameterSymbol"/>.
/// </summary>
/// <param name="typeParameterSymbol">The typeParameterSymbol to act on.</param>
/// <param name="includeInterfaces">(Optional) True to include, false to exclude the interfaces.</param>
/// <returns/>
public static IEnumerable <ITypeSymbol> GetAllConstraintTypes(this ITypeParameterSymbol typeParameterSymbol, bool includeInterfaces = true)
{
typeParameterSymbol.ThrowOnNull(nameof(typeParameterSymbol));
var constraintTypes = includeInterfaces
? GetAllConstraintTypesImplementation(typeParameterSymbol)
: GetAllConstraintTypesImplementation(typeParameterSymbol)
.Where(type => type.TypeKind != TypeKind.Interface);
return(constraintTypes.Distinct());
//---------------------------------Local Functions--------------------------------------------------------
IEnumerable <ITypeSymbol> GetAllConstraintTypesImplementation(ITypeParameterSymbol typeParameter, int recursionLevel = 0)
{
const int maxRecursionLevel = 40;
if (recursionLevel > maxRecursionLevel || typeParameter.ConstraintTypes.Length == 0)
{
yield break;
}
foreach (ITypeSymbol constraintType in typeParameter.ConstraintTypes)
{
if (constraintType is ITypeParameterSymbol constraintTypeParameter)
{
var nextOrderTypeParams = GetAllConstraintTypesImplementation(constraintTypeParameter, recursionLevel + 1);
foreach (ITypeSymbol type in nextOrderTypeParams)
{
yield return(type);
}
}
else
{
yield return(constraintType);
}
}
}
}
