Bug 3847 - Peculiar foreach behaviour with regard to closures.
Summary: Peculiar foreach behaviour with regard to closures.
Alias: None
Product: Compilers
Classification: Mono
Component: C# ()
Version: unspecified
Hardware: PC All
: --- normal
Target Milestone: ---
Assignee: Marek Safar
Depends on:
Reported: 2012-03-11 10:24 UTC by Daniil Frumin
Modified: 2012-03-13 06:27 UTC (History)
1 user (show)

Is this bug a regression?: ---
Last known good build:

example (319 bytes, text/plain)
2012-03-11 10:25 UTC, Daniil Frumin

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Description Daniil Frumin 2012-03-11 10:24:14 UTC
The attached file, when compiled under the Mono C# compiler version, produces the following output:

While the result indeed mimics .NET's behaviour it is clear that there was a design error (at least according to people on SO), since it is expected for closures in that case to enclose on _different_ variables. Microsoft has recently changed the implementation of foreach and the behaviour is no longer perplexing in VS11.

I do understand that patching foreach might break some backward compatibility in theory, but in practice I can't honestly find a usecase for this (e.g.: when you need all of your closures to be enclosed on one variable with the last value).

Please pardon my English as I am not a native speaker.
Comment 1 Daniil Frumin 2012-03-11 10:25:22 UTC
Created attachment 1494 [details]
Comment 2 Marek Safar 2012-03-13 06:27:47 UTC
Fixed in master