Simon Peyton Jones

So we've become more and more taking into account the needs of our users.

But in a way, the sort of cultural heritage is we never give up on the one core principle.

We're just not going to give you unrestricted side effects.

Sorry.

You've got to say and put up with the consequences.

So we're going to stick to one core principle, and then we'll do lots of work around the average to make that better.

That does limit our community somewhat, right?

It does mean you really have to think in a different way.

Immutability changes everything.

That means you'd have to think a different way about programming.

Maybe you don't want to think in a different way.

That's fine.

Then don't use Haskell, right?

So in a way, we started from a very small user community, a very sort of pure and nerdy one, and growing larger and larger, but all slowly, but all the time maintaining faithfulness to this core principle.

Oh, it was a mistake, right?

It was a bug.

It wasn't deliberate.

And it only happened, you know, how did the bug get out?

Because, of course, if it always did that, we'd have noticed.

How did it get into a release?