private static bool TryGenerateForEnumerable(Type type, ref EqualityFunction <T> result)
{
if (type.CustomAttributes.OfType <NotEnumerableComparisonAttribute>().Any())
{
return(false);
}
Type enumerableInterface =
type.GetInterfaces()
.Concat(new[] { type })//this one handles the case where type is IEnumerable itself
.Where(x => x.IsGenericType && x.GetGenericTypeDefinition() == typeof(IEnumerable <>))
.FirstOrDefault();
if (enumerableInterface == null)
{
return(false);
}
Type itemType = enumerableInterface.GetGenericArguments().Single();
ParameterExpression left = Expression.Parameter(type, "x");
ParameterExpression right = Expression.Parameter(type, "y");
result = Expression.Lambda <EqualityFunction <T> >(
Expression.Call(
instance: null,
method: NotEquals.GetSequenceNotEqualMethod(itemType, type),
arguments: new[] { left, right }
),
left,
right
).Compile();
return(true);
}
private static bool TryGenerateForIEquatable(Type type, ref EqualityFunction <T> result)
{
Type equatableInterface = typeof(IEquatable <>).MakeGenericType(type);
bool implements = type.GetInterfaces().Any(x => x == equatableInterface);
if (!implements)
{
return(false);
}
if (type.GetCustomAttributes <EquatableDependsOnLazyComparisonAttribute>().Any())
{
return(false);
}
ParameterExpression left = Expression.Parameter(type, "x");
ParameterExpression right = Expression.Parameter(type, "y");
MethodInfo compareMethod = NotEquals.GetEquatableCompareMethod(type);
result = Expression.Lambda <EqualityFunction <T> >(
Expression.Call(
instance: null,
method: NotEquals.GetEquatableCompareMethod(type),
arguments: new[] { left, right }
),
parameters: new[] { left, right }
).Compile();
return(true);
}