// The 'rightParameter' argument is not used but by having the same signature for both methods allows for a few optimizations in other places.
public static Expression CreateGetHashCodeExpression <TProperty>(
PropertyInfo property,
AutoEqualityPropertyAttribute attribute,
Expression leftParameter,
Expression rightParameter)
{
if (property.PropertyType == typeof(string) || property.PropertyType.IsEnum)
{
// Short-cut to have compiler write this expression for us.
var getHashCodeFunc = (Expression <Func <TProperty, int> >)((obj) => GetComparer <TProperty>(attribute).GetHashCode(obj));
return(Expression.Invoke(
getHashCodeFunc,
Expression.Property(leftParameter, property)
));
}
// Call the instance 'GetHashCode' method by default.
var getHashCodeMethod = property.PropertyType.GetMethod(nameof(GetHashCode));
// ReSharper disable once AssignNullToNotNullAttribute - getHashCodeMethod is never null
return(Expression.Call(
Expression.Property(leftParameter, property),
getHashCodeMethod
));
}
private static IEqualityComparer <TProperty> GetComparer <TProperty>(AutoEqualityPropertyAttribute attribute)
{
if (typeof(TProperty) == typeof(string))
{
return((IEqualityComparer <TProperty>)StringComparers[attribute.StringComparison]);
}
return(EqualityComparer <TProperty> .Default);
}
public static Expression CreateEqualsExpression <TProperty>(
PropertyInfo property,
AutoEqualityPropertyAttribute attribute,
Expression leftParameter,
Expression rightParameter)
{
if (property.PropertyType == typeof(string) || property.PropertyType.IsEnum)
{
// Short-cut to have compiler write this expression for us.
var equalsFunc = (Expression <Func <TProperty, TProperty, bool> >)((x, y) => GetComparer <TProperty>(attribute).Equals(x, y));
return(Expression.Invoke(
equalsFunc,
Expression.Property(leftParameter, property),
Expression.Property(rightParameter, property)
));
}
var equalsMethod = GetEqualsMethod(property.PropertyType);
return(Expression.Call(Expression.Property(leftParameter, property), equalsMethod, Expression.Property(rightParameter, property)));
}
