Comments on: LINQ query operators and null lists http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/ Strong opinions, weakly held Tue, 18 Jun 2013 19:00:00 +0000 hourly 1 http://wordpress.org/?v=3.4.2 By: Wes McClure http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2067 Wes McClure Thu, 10 Dec 2009 06:09:53 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2067 Yeah, my biggest pet peeve is ForEach exploding with null sources... why not just ignore it? I try to always silently ignore null sources in extension methods unless it really doesn't make sense. Wouldn't it be nice if regular instance methods worked like python by taking the instance as a parameter so we could silently deal with nulls there too! Yeah, my biggest pet peeve is ForEach exploding with null sources… why not just ignore it? I try to always silently ignore null sources in extension methods unless it really doesn’t make sense.

Wouldn’t it be nice if regular instance methods worked like python by taking the instance as a parameter so we could silently deal with nulls there too!

]]> By: superbecio http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2066 superbecio Wed, 09 Dec 2009 15:10:15 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2066 I don't agree with the fact that methods returning collections should never return null, rather I prefer to use that special value as a signal for user canceled operations. I don’t agree with the fact that methods returning collections should never return null, rather I prefer to use that special value as a signal for user canceled operations.

]]> By: bogardj http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2065 bogardj Wed, 09 Dec 2009 14:19:15 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2065 @Tommy, @Mike Nice! Thanks for the tip! @Tommy, @Mike

Nice! Thanks for the tip!

]]> By: Mike http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2064 Mike Wed, 09 Dec 2009 13:44:44 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2064 Save yourself a few lines of code by using a null-coalescing operator return source ?? Enumerable.Empty<TSource>(); Save yourself a few lines of code by using a null-coalescing operator

return source ?? Enumerable.Empty();

]]> By: Tommy Carlier http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2063 Tommy Carlier Wed, 09 Dec 2009 13:42:14 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2063 You could make that shorter by using the coalescing operator: public static IEnumerable<TSource> NullToEmpty<TSource>( this IEnumerable<TSource> source) { return source ?? Enumerable.Empty<TSource>(); } You could make that shorter by using the coalescing operator:

public static IEnumerable NullToEmpty(
this IEnumerable source)
{
return source ?? Enumerable.Empty();
}

]]> By: Vitaly Stakhov http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2062 Vitaly Stakhov Wed, 09 Dec 2009 06:41:16 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2062 Conceptually you're trying to see if there is an element in 'null' collection. Sometimes it's like division by zero. If Microsoft ignored null collections, that would be similar to mark all classes in the project as [Serializable] (yes, there are benefits - you don't get SerializationException, but objects that are not expected to be serialized actually will be). So, my point is to leave constraints as tough as possible. Anyway, there is always a choice either to define/use NullOrEmpty or not. If nulls were ignored by extension methods the choice would not exist. There could be an option in linq inself to ignore or not though. Conceptually you’re trying to see if there is an element in ‘null’ collection. Sometimes it’s like division by zero.

If Microsoft ignored null collections, that would be similar to mark all classes in the project as [Serializable] (yes, there are benefits – you don’t get SerializationException, but objects that are not expected to be serialized actually will be).

So, my point is to leave constraints as tough as possible. Anyway, there is always a choice either to define/use NullOrEmpty or not. If nulls were ignored by extension methods the choice would not exist.

There could be an option in linq inself to ignore or not though.

]]> By: John Farrell http://lostechies.com/jimmybogard/2009/12/08/linq-query-operators-and-null-lists/#comment-2061 John Farrell Wed, 09 Dec 2009 05:00:35 +0000 /blogs/jimmy_bogard/archive/2009/12/08/linq-query-operators-and-null-lists.aspx#comment-2061 Nice, this the most useful 4 lines of code I've seen in a while. Nice, this the most useful 4 lines of code I’ve seen in a while.

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