Separating a Hash type from Object

Brendan Eich brendan at
Wed May 2 12:26:32 PDT 2007

On May 2, 2007, at 11:44 AM, Peter Hall wrote:

> I'm wondering what is so wrong with Hash.set(key, value) and  
> Hash.get(key)....

Nothing's wrong, but the "rightness" of object literals in  
particular, and . or [] for accessing values by key, will make  
anything like this less successful than you might hope. Syntax is the  
UI, it matters.

We actually started down this road at a recent meeting, and ran into  
another, non-syntactic issue: often one wants weak reference support  
for keys, and sometimes even for values. Flash's Dictionary class has  
a "weakKeys" flag parameter to its ctor. There's lots of prior art  
here -- Allen Wirfs-Brock cited Barry Hayes's Ephemerons (http://, for example.

This complexity again made us shy away from any late-breaking  
significant feature. Adding GC requirements on all implementations  
needs to be done with care, and with enough time to implement and test.


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