what's so difficult about namespace?

[Gene]

On Nov 26, 1:29 am, Xah Lee <xah... at gmail.com> wrote:
> comp.lang.lisp,comp.lang.functional,comp.lang.perl.misc,comp.lang.python,co­mp.lang.java.programmer
>
> 2008-11-25
>
> Recently, Steve Yegge implemented Javascript in Emacs lisp, and
> compared the 2 languages.
>
> http://steve-yegge.blogspot.com/http://code.google.com/p/ejacs/
>
> One of his point is about emacs lisp's lack of namespace.
>
> Btw, there's a question i have about namespace that always puzzled me.
>
> In many languages, they don't have namespace and is often a well known
> sour point for the lang. For example, Scheme has this problem up till
> R6RS last year. PHP didn't have namespace for the past decade till
> about this year. Javascript, which i only have working expertise,
> didn't have namespace as he mentioned in his blog. Elisp doesn't have
> name space and it is a well known major issue.
>
> Of languages that do have namespace that i have at least working
> expertise: Mathematica, Perl, Python, Java. Knowing these langs
> sufficiently well, i do not see anything special about namespace. The
> _essence_ of namespace is that a char is choosen as a separator, and
> the compiler just use this char to split/connect identifiers.
> Although i have close to zero knowledge about compiler or parser, but
> from a math point of view and my own 18 years of programing
> experience, i cannot fathom what could possibly be difficult of
> introducing or implementing a namespace mechanism into a language. I
> do not understand, why so many languages that lacks so much needed
> namespace for so long? If it is a social problem, i don't imagine they
> would last so long. It must be some technical issue?
>
> Could any compiler expert give some explanation?
>
> Thanks.
>
>   Xah
> ∑http://xahlee.org/
>
> ☄

When multiple existing systems are combined, namespaces provide a
quick way to prevent name clashes.