Re^2: can sub check context for lvalue vs rvalue context?

[haukex]

What would your wantlvalue return if called this way: @x = x() = 5;?

I think operator associativity can help answer that one:

$ perl -MO=Deparse -e ' @x = x() = 5; '
@x = (x() = 5);

So I'd say that x() is primarily in lvalue context here. And what's being assigned to @x is not the return value of x(), but the return value of the assignment operation, which is an lvalue itself.

$ perl -le 'sub x : lvalue { $a } (x() = 4) = 2; print $a'
2

[BrowserUk]

So I'd say that x() is primarily in lvalue context here.

That implies it has a secondary context. It doesn't. When an lvalue sub is called, it always does the same thing. Returns an lvalue to the calling context.

And what's being assigned to @x is not the return value of x(), but the return value of the assignment operation, which is an lvalue itself.

What is assigned to @x, is the result of the rvalue expression. And that, is the result of the assignment to lvalue returned by the subroutine.

[haukex]

That implies it has a secondary context. It doesn't.

Yes, of course - I was a little sloppy with my language.

And what's being assigned to @x is not the return value of x(), but the return value of the assignment operation, which is an lvalue itself.

What is assigned to @x, is the result of the rvalue expression. And that, is the result of the assignment to lvalue returned by the subroutine.

Yes, I think we're both saying the same thing here.