public static Type GetCustomEqualityComparerTypeFor([NotNull] Type itemType, IEqualityComparisonConfiguration equalityComparisonConfiguration = null)
{
equalityComparisonConfiguration = equalityComparisonConfiguration ?? EqualityComparisonConfiguration.Default;
if (itemType == null)
{
throw new ArgumentNullException(nameof(itemType));
}
// NOTE: Don't change 'if' blocks order.
Type elementType;
if (itemType.IsArray)
{
if (itemType.GetArrayRank() == 1)
{
elementType = itemType.GetElementType() ?? throw new InvalidOperationException($"Unexpected error occured. Can't get element type for '{itemType}'.");
if (elementType.IsEnum)
{
return(typeof(EnumArrayEqualityComparer <>).MakeGenericType(elementType));
}
if (elementType.IsGenericAssignable(typeof(IEquatable <>)))
{
if (equalityComparisonConfiguration.PreferBuiltInEquatableImplementation)
{
return(elementType.IsValueType
? typeof(EquatableValueTypeArrayEqualityComparer <>).MakeGenericType(elementType)
: typeof(EquatableReferenceTypeArrayEqualityComparer <>).MakeGenericType(elementType));
}
if (elementType.IsValueType)
{
return(TryGetUnmanagedTypeArrayEqualityComparerType(elementType, out var comparerType)
? comparerType
: typeof(EquatableValueTypeArrayEqualityComparer <>).MakeGenericType(elementType));
}
return(typeof(EquatableReferenceTypeArrayEqualityComparer <>).MakeGenericType(elementType));
}
if (elementType.IsNullable(out var nullableUnderlyingType))
{
return(typeof(NullableValueTypeArrayEqualityComparer <>).MakeGenericType(nullableUnderlyingType));
}
return(typeof(ReferenceTypeArrayEqualityComparer <>).MakeGenericType(elementType));
}
return(typeof(MultiDimensionalArrayEqualityComparer));
}
if (itemType.IsGenericAssignable(typeof(List <>), out var listType))
{
elementType = listType.GetGenericArguments()[0];
if (elementType.IsNullable(out var nullabelUnderlyingType))
{
return(typeof(NullableValueTypeListEqualityComparer <>).MakeGenericType(nullabelUnderlyingType));
}
if (elementType.IsValueType)
{
return(typeof(ValueTypeListEqualityComparer <>).MakeGenericType(elementType));
}
return(typeof(ReferenceTypeListEqualityComparer <>).MakeGenericType(elementType));
}
if (itemType.IsGenericAssignable(typeof(IReadOnlyDictionary <,>), out var dictionaryType))
{
var kvpGenericArgs = dictionaryType.GetGenericArguments();
var keyType = kvpGenericArgs[0];
var valueType = kvpGenericArgs[1];
return(typeof(DictionaryEqualityComparer <, ,>).MakeGenericType(keyType, valueType, itemType));
}
if (itemType.IsCollection(out elementType))
{
if (elementType.IsNullable(out var nullabelUnderlyingType))
{
return(typeof(NullableValueTypeCollectionEqualityComparer <>).MakeGenericType(nullabelUnderlyingType));
}
if (elementType.IsValueType)
{
return(typeof(ValueTypeCollectionEqualityComparer <>).MakeGenericType(elementType));
}
return(typeof(ReferenceTypeCollectionEqualityComparer <>).MakeGenericType(elementType));
}
return(typeof(ObjectStructureEqualityComparer <>).MakeGenericType(itemType));
}
public ObjectStructureEqualityComparer([NotNull] IEnumerable <PropertyInfo> properties, [CanBeNull] IEqualityComparisonConfiguration configuration = null)
: this((properties ?? throw new ArgumentNullException(nameof(properties))).Select(p => (p as MemberInfo, p.PropertyType)), configuration)
public static LambdaExpression CreateEqualsExpression([NotNull] Type itemType, IEqualityComparisonConfiguration configuration = null)
{
if (itemType == null)
{
throw new ArgumentNullException(nameof(itemType));
}
configuration = configuration ?? EqualityComparisonConfiguration.Default;
LambdaExpression elementTypeComparer;
if (itemType.IsEnum)
{
elementTypeComparer = CreateForEnums(itemType);
}
else if (itemType == typeof(string))
{
elementTypeComparer = CreateForStrings(configuration.StringComparisonMode);
}
else if (itemType.IsBuiltInPrimitive() ||
itemType.IsAssignableFrom(typeof(IEquatable <>).MakeGenericType(itemType)))
{
elementTypeComparer = CreateForPrimitiveType(itemType);
}
else if (itemType.IsNullable(out Type nullableUnderlyingType))
{
elementTypeComparer = nullableUnderlyingType.IsEnum
? CreateForNullableEnums(itemType)
: CreateForDefaultEqualityComparer(itemType);
}
else if (itemType.IsCollection(out Type elementType) ||
itemType.IsReadOnlyDictionary(out _, out elementType))
{
elementTypeComparer = GetEqualsExpressionForCollection(itemType, elementType);
}
public ObjectStructureEqualityComparer(IEqualityComparisonConfiguration configuration) : this(typeof(T).GetPublicInstanceProperties(), configuration)
{
}
