Is C# LINQ fully reliable/supported?

I'm trying to use LINQ, but notice sometimes I get a bunch of compiler errors related to using LINQ. But then if I re-compile the code, the compiler errors no longer appear. They only appear about 5% of the time. It makes me nervous. (Sorry I don't have the actual compiler errors, because right now I cant reproduce the issue)
I've read other threads where people say LINQ is reliable, others say it isn't.

Here is the problematic code:

Code (csharp):

1.  
2. public void TestLINQ(float ff)
3.    {
4.      string variableName = GetVariableName(() => ff);
5.    }
6.  
7.    public static string GetVariableName<T>(System.Linq.Expressions.Expression<Func<T> > expr)
8.    {
9.      string varName = ((System.Linq.Expressions.MemberExpression) expr.Body).Member.Name;
10.  
11.      return (varName);
12.    }
13.  
14.  

The code is supposed to return the variable name. When the code compiles, it works at runtime.
I know little about LINQ. I'm trying to use it for the process of serializing data for save/load games.
Does anyone else have intermittent issues with LINQ?

 

Don't use the default LINQ if you plan to publish an iOS build. Methods like OrderBy and alike may produce AOT/JIT errors.
Use UniLinq instead:
https://github.com/RyotaMurohoshi/UniLinq

I've been extensively using it in my current project, works great.

 

Ok, just to be safe I found a different method, avoiding LINQ.
I don't fully understand LINQ and don't have a warm feeling about it.

i was able to replace the code by using
System.Runtime.InteropServices

 

System.Runtime.InteropServices is usually used for totally different kind of operations. I honestly would not use it for replacing LINQ. And don't be afraid, LINQ is typically one of the best dev code extensions out there and is heavily used in C# projects. You should be good to go with it as it will sooner or later simplify your live a lot.

Just as an example let's assume you have numerous entries of some kind of data (as a model) collected in a list "myInputList" and you just want to work with a sub selection of that list where the SelectionType property is "TakeMe".

Code (CSharp):

1. // LINQ way
2. var myOutputList = myInputList.Where(entry => entry.SelectionType == "TakeMe");
3.  
4. // old way
5. var myOutputList = new List<MyModel>();
6. foreach(var entry in myInputList)
7. {
8.     if (entry.SelectionType == "TakeMe")
9.     {
10.         myOutputList.Add(entry);
11.     }
12. }

So instead of writing 8 lines of code you have just 1.

No, I'm not paid by Microsoft, I just try to encourage easily readable and writable code.

 

It looks like this is worth learning.

 

Unity's running on an old version of Mono, which among other bug has some nasty issues where collections generate garbage.

The most prominent example is a few bytes generated by any foreach-loop, but I'm pretty sure that many of the linq calls generates some garbage. This doesn't mean "Don't use LINQ", it just means "avoid it in loops that run a lot".

 

LINQ can make some tasks with lists and collections so much easier with much more concise code, but as mentioned is probably best avoided in places where performance is paramount.