Subj : Re: Any reason for Math.sin.__parent__ == Math ?
To   : Igor Bukanov <igor@fastmail.fm>
From : Brendan Eich <brendan@meer.net>
Date : Mon Mar 29 2004 10:01 am

Igor Bukanov wrote:
> Hi!
> 
> In the current SM parent scope for functions of the standard host 
> objects points to the object itself and not to the global scope so:
> 
> js> Math.sin.__parent__ == Math
> true
> js>  Math.sin.__parent__
> [object Math]
> js> Math.sin.__parent__.__parent__
> [object global]
> js>
> 
> Any reason for that? It seems ECMA 262 is silent on this issue.

__parent__ is a generalization of [[Scope]], which ECMA-262 Edition 3 
specifies only for Function objects created per 13.2.  The spec does not 
cover the [[Scope]] property of native function objects.

SpiderMonkey defines all static methods (Math.sin is analogous to 
Date.parse in this respect; they are called static methods after Java's 
class-member static methods) in the scope of their class constructor or 
prototype.  Math is not a constructor, it's a prototype singleton.

Is this ancient self-consistent behavior of SpiderMonkey causing some 
script use-case, or perhaps Rhino, some stress?

/be

.