catch-if syntax?

Brendan Eich brendan at
Thu Sep 13 21:33:13 PDT 2007

On Sep 13, 2007, at 7:23 PM, Dominic Cooney wrote:

> I notice that the normative grammar* doesn't mention SeaMonkey's catch
> (identifier if expr) syntax for filtering exceptions. Is that
> deliberate?

Yes, that was a SpiderMonkey (not SeaMonkey, n.b.; it may also be  
supported in Rhino) extension rejected during the ES3 era and not re- 
submitted since.

ES4 does have type-annotated catch variables, which match based on  
first "is" type relation, IIRC.


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