What does this notation involving angle brackets mean?

Question

I'm reading Async in C# 5.0, and the section on the compiler transform contains this snippet:

public Task<int> AlexsMethod()
{
    <AlexsMethod>d__0 stateMachine = new <AlexsMethod>d__0();
    stateMachine.<>4__this = this;
    stateMachine.<>t__builder = AsyncTaskMethodBuilder<int>.Create();
    stateMachine.<>1__state = -1;
    stateMachine.<>t__builder.Start<<AlexsMethod>d__0>(ref stateMachine);
    return stateMachine.<>t__builder.Task;
}

There are two pieces of notation that are new to me. The first is <AlexsMethod>d__0. The second is stateMachine.<>4__this. Neither works when I try them myself, so I suspect it's for use by the compiler only. But I'm having trouble searching for more information on what is intended by this notation.

Someone made a post on SO once showing a lot of what the C# compiler (at the time - subject to change) made - all of the random little characters (e.g. the `4` in `4__this`) you see have an implicit meaning. Edit: here it is: http://stackoverflow.com/questions/2508828/where-to-learn-about-vs-debugger-magic-names — Tim S., Jun 15 '13 at 18:21

Tim S. · Accepted Answer · 2014-10-29T18:44:44.070

8

Unlike the brackets marking generics (e.g. Task<int>), they don't have special meaning. They're just what the compiler generates - identifiers that are valid in IL, but not in C#.

edited Oct 29 '14 at 18:44

answered Jun 15 '13 at 18:21

Tim S.

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And the code which generates the names is [here](https://github.com/dotnet/roslyn/blob/master/src/Compilers/CSharp/Portable/Symbols/Synthesized/GeneratedNames.cs) (borrowed from [this answer](https://stackoverflow.com/a/2509524/774575)) – mins Jul 06 '19 at 06:18

score 0 · Answer 2 · edited Jul 03 '17 at 13:07

0

When you use lambda expression, lambda expression is a anonymous method. But compiler need to give it a name, so these methods are generated by compiler, it is not readable for human.

edited Jul 03 '17 at 13:07

Romano Zumbé

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answered Jun 15 '13 at 23:06

ntwo1980

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What does this notation involving angle brackets mean?

2 Answers2