[doorhammer]

> Erlang: genuinely useful for its use case, distributed systems. This is a language where the intended use was really woven in the language design, to great effect. For the rest, it's a bit like ML without types. Personally, I see no good reason for leaving out types, so that tends to annoy me a bit.

I believe there's an interview with Joe Armstrong (creator of Erlang) where he mentions that the one thing he'd wished he'd added to Erlang was a type system at the jump. I'm not a 100% sure on that, though.

In Learn You Some Erlang for Great Good they talk about the lack of types in erlang [1]. Apparently some Haskell folks wanted to make a type system for Erlang, so they called up Joe Armstrong and asked what he thought. (this is all a really cursory outline; check the sources for better info)

Joe Armstrong recounts the story and says that Philip Wadler told him "he had a one year’s sabbatical and was going to write a type system for Erlang and “were we interested?” Answer —'Yes.'"

Philip went on to write a paper [2] about the type system they wrote, but obviously it never really got traction. More info in The History of Erlang [3]

I don't really have a particular point to this, other than it's interesting and maybe of some historical interest to folks looking into PL's and how they end up getting made.

[1] http://learnyousomeerlang.com/types-or-lack-thereof [2] http://homepages.inf.ed.ac.uk/wadler/papers/erlang/erlang.pd... [3] http://webcache.googleusercontent.com/search?q=cache:ZHq_V41... (google cached version; couldn't find another version right off hand)