Subj : Re: "named" vs. anonymous function
To   : netscape.public.mozilla.jseng
From : Jens Thiele
Date : Mon Dec 13 2004 04:10 pm

Brendan Eich schrieb:
> To clarify further, a named function object, per ECMA-262 Edition 3
> 11.2.5 and 13, the production:
> 
> FunctionExpression :
>     function Identifier ( FormalParameterListopt ) { FunctionBody }
> 
> A named function expression is scoped by an Object created to hold its
> name only while it is active.  That is its activation's scope parent, so
> that cannot match the compiler-visible static scope parent (the global
> object in your js shell example).  Hence the clone.
> 
> Named and anonymous function objects do have different scope chains, per
> ECMA-262 Edition 3, but that does not map directly onto the __proto__
> difference you discovered.  The latter is really an implementation
> detail allowed by the spec.
> 
> /be

So this this is not really a matter of named vs. anonymous function but
a matter of scope?

Test:
js> (function(){return function(){};})().__proto__===Function.prototype
false
js> (function(){return
function(){};})().__proto__.__proto__===Function.prototype
true

though this example strictly wouldn't require a scope object?

perhaps better?
js> (function (){var i=10;return function(){return
i;};})().__proto__===Function.prototype
false
js> (function (){var i=10;return function(){return
i;};})().__proto__.__proto__===Function.prototype
true

looking at the source (jsinterp.c)
the relevant parts seem to be:
JSOP_ANONFUNOBJ, JSOP_NAMEDFUNOBJ and JSOP_CLOSURE
(probably not JSOP_DEFFUN)

in any way it is the call to js_CloneFunctionObject
creating the clone / additional prototype

I think I better stop now and get back to work again. Curiosity killed
the cat ;-)

Thanks
Jens

.