Comments on Meeting Notes

Allen Wirfs-Brock allen at
Wed Dec 12 08:18:36 PST 2012

For non-strict functions, formal parameters and the argument object can share the same storage on the processor stack. Strict functions require a copy, if either a formal or an args object element is modified. The conserative implementation is to always copy.

AllenBrendan Eich <brendan at> wrote:Axel Rauschmayer wrote:
> Can you explain? What is this copying price and why don’t non-strict 
> functions have to pay it?

Strict functions have an arguments object that does not alias formal 

js> function f(x) { print(x); arguments[0] = 42; return x; }
js> f(99)
js> function g(x) { "use strict"; print(x); arguments[0] = 42; return x; }
js> g(99)

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