public static ConditionalExpression GetNullCheckedConversion(Expression nullableValue, Expression nonNullResult)
{
var nullValue = DefaultValueConstantExpressionFactory.CreateFor(nullableValue);
var fallbackValue = DefaultValueConstantExpressionFactory.CreateFor(nonNullResult);
var value = Expression.Condition(
Expression.NotEqual(nullableValue, nullValue),
nonNullResult,
fallbackValue);
return(value);
}
public static bool TryConvert(
MethodCallExpression methodCall,
IQueryProjectionModifier modifier,
out Expression converted)
{
if (modifier.Settings.SupportsGetValueOrDefault || IsNotGetValueOrDefaultCall(methodCall))
{
converted = null;
return(false);
}
// ReSharper disable once AssignNullToNotNullAttribute
converted = Expression.Condition(
methodCall.Object.GetIsNotDefaultComparison(),
Expression.Convert(methodCall.Object, methodCall.Type),
DefaultValueConstantExpressionFactory.CreateFor(methodCall));
return(true);
}
protected override MemberBinding VisitMemberBinding(MemberBinding binding)
{
if (binding.BindingType != MemberBindingType.Assignment)
{
return(base.VisitMemberBinding(binding));
}
var memberBinding = (MemberAssignment)binding;
if (memberBinding.Expression.Type.CanBeNull())
{
return(base.VisitMemberBinding(binding));
}
var bindingValueOrNull = Expression.Condition(
_conditional.Test,
memberBinding.Expression,
DefaultValueConstantExpressionFactory.CreateFor(memberBinding.Expression));
return(memberBinding.Update(bindingValueOrNull));
}
