On Mon, Jul 18, 2016 at 1:28 AM, Levi Morrison <le...@php.net> wrote:
> > I don't think this is realistic. > > I'll come back to this one in a moment. > > > As such: > > > > Option B: foo() in namespace Bar will > > a) Check if Bar\foo() exists > > b) Otherwise check if foo() exists > > c) Otherwise try to load 'Bar\foo' > > d) Otherwise try to load 'foo' > > e) If all fails, throw. > > > > This avoids the autoloading overhead when calling functions from the > global > > namespace. However this also means that you cannot autoload a function > with > > the same name as a global function through an unqualified call. > > > > In practice, this is probably less problematic than it might sound, > because > > realistically function autoloading would likely operate on the > > namespace-level rather than the function level, i.e. if one function > from a > > namespace is loaded all of them are, because they are all defined in the > > same file. In such a setting you would never run into this problem as > there > > would be no unqualified calls to functions that have not been loaded yet. > > However, it *would* be an issue if you tried to, say, map each function > to > > a separate file. > > If we are going to use the "one file for all functions" as > justification for defining this behavior a certain way then please > acknowledge it helps both options. One extra autoload from option A is > not a big deal if we are okay with this "one file for all functions" > justification. If we are not okay with that justification then I don't > think option B is viable either. > I don't follow what you mean here. The problem is not the case where the unqualified call actually refers to a namespaced function. The problem is the case where it refers to a global function (which is also far more likely). In this case option A requires that we invoke the autoloader for each call. A relaxed variant would only invoke the autoloader once for each call, assuming that a function that is not loadable at one time will never become loadable (which is of course a significant restriction). The former variant would be prohibitively slow. The latter is more realistic, but I expect it to have non-trivial performance impact nonetheless. As all of this only applies to the case where the unqualified call refers to a global function, it does not actually matter how you namespace things (single or multiple files). As such, I'm not sure I understand your argument. > I think a better option is to try to solve this in 8 by unifying how > functions and classes (and interfaces and traits) work in namespaces. > Ideally the lookup behavior should be the same and all that differs > are the symbol tables being looked in. > Are you suggesting that we require global function references to be written as fully qualified names? This would be a huge BC break for namespaced code. Regards, Nikita
