Language Size (was Re: [TLUG]: ECMAScript ("Javascript") Version 4 - FALSE ALARM)

Brendan Eich brendan at
Wed Oct 31 09:27:47 PDT 2007

On Oct 31, 2007, at 4:45 AM, Harri Porten wrote:

> But seriously: from my own work on an ES4 interpreter (based on the
> previous draft back then) I saw the biggest impact on the  
> implementation
> to be in the "compilation phase". This went hand in the hand with the
> *advantages* of the type system, i.e. the possibility to apply
> optimizations before execution.

(Just want to reconfirm that none of these analyses for optimization  
or any other reason are required. Also, FWIW, the more we look at JS  
optimization the more runtime techniques seem to do better; we  
haven't looked at agressive ahead of time compilation techniques of  

> In my personal book I therefore judge the complexity of a language  
> also
> based on the observation whether runtime implementations typically  
> include
> a compiler, i.e. offer an eval() function or not.

ES4 requires eval, as ES3 did. We're not sure what will become of the  
ES3 compact profile ( 
standards/Ecma-327.htm), but it is a bit of a flop on anything web- 
connected. I don't see the need to leave out eval. Flash does  
implement the compact profile, but from the self-hosted ES4 compiler  
that Jeff Dyer has built on top of Tamarin, it looks like Flash will  
have eval too.


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