Neil Mix nmix at pandora.com
Wed Aug 13 20:45:56 PDT 2008

On Aug 13, 2008, at 8:02 PM, Peter Michaux wrote:

> Are these
> type-related features what the community of ECMAScript 3 programmers
> were really asking for emphatically years ago? Is the community really
> asking for now with the surge of functional programming?

One hacker's opinion: Yes, absolutely.  The big pain point for me has  
been scaling an app out from a team of 1 with <10K LOC to a team of  
many with 100K+ LOC.  Even with an incredibly rigorous testing  
infrastructure (comparable in code size to the product itself),  
development on the application just hasn't scaled well. Many JS  
hackers don't build apps at a large scale, but JS-based apps will only  
get bigger in scope over time, so this pain point will get more acute.

It's all about time spent.  A large app is impossible for a new-hire  
programmer to comprehend end-to-end.  We mitigate this by using unit  
tests as a safety barrier, but over time our tests have grown to take  
about 10 minutes or so to run.  That's way too long to wait for a  
pesky misspelling bug.  To the extent that there's static type  
checking available to catch errors early on, it's a huge productivity  
gain. (Although not necessarily one that's easily noticed -- one tends  
not to see the problems that grow and kill slowly.)

Your statement above implies that types and functional programming are  
mutually exclusive.  Are they?  I don't see it that way.

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