Strategies for standardizing mistakes

Jim Blandy jimb at
Thu Oct 15 09:54:17 PDT 2009

On 10/14/2009 06:36 PM, Mike Shaver wrote:
> Our implementation of String.prototype.match checks the context in
> which it's called, to see if it need bother with the expense of
> constructing the result array (it needn't, if the match call is being
> used simply as a test, which isn't unheard of on the web).  That
> optimization aged pretty well, and indeed benchmarks often encourage
> such context-sensitivity.

It aged well because it obeys the fundamental principle of optimization: 
"Lying is fine as long as you don't get caught."  You haven't changed 
the meaning of the language.  document.all is in a different category, 
because it's observable.

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