Does LINQ have a sequence operator, which allows to perform some action on every element without projecting it to a new sequence?
This might see a bit awkward, but just for me to know :)
Example:
IEnumerable<IDisposable> x;
x.PERFORM_ACTION_ON_EVERY_ELEMENT(m => m.Dispose());
Obviously, this could be done using something like:
foreach (var element in x) x.Dispose();
But if something actually exists, that would be nice.
No, it doesn't exist. Specifically for the reason you mention: It seems awkward having a single operator that behaves completely different than all the others.
Eric Lippert, one of the C# Compiler developers has an article about this.
But we can go a bit deeper here. I am philosophically opposed to providing such a method, for two reasons.
The first reason is that doing so violates the functional programming principles that all the other sequence operators are based upon. Clearly the sole purpose of a call to this method is to cause side effects.
The purpose of an expression is to compute a value, not to cause a side effect. The purpose of a statement is to cause a side effect. The call site of this thing would look an awful lot like an expression (though, admittedly, since the method is void-returning, the expression could only be used in a “statement expression” context.)
It does not sit well with me to make the one and only sequence operator that is only useful for its side effects.