RE: [boost] Review: lambda library

From: Asger Alstrup Nielsen (alstrup_at_[hidden])
Date: 2002-03-22 13:24:23

Just a few comments to your kind reply.

> So why should everyone else wait 1.5 years for another 
> "better" library to come out? A new one won't break 
> existing code using LL. We are not proposing
> to change the C++ Standard, only offering a very useful 
> library that has had a lot of work put into it. That is 
> reasonably well tested and to us seemsvery useful as is.

People can download the library and use it if they want to, because you
make it publically available, today. The interested users do not have to
wait. They can use it today if they want to, thanks to your generous
licensing.

Of course, Boost increases the user base significantly because once it
is in there, it has got a stamp of approval and a distribution process
going. Also, the review process itself improves the library.
But the other side of the coin is that once it is in Boost, it will
become harder to change it, because you have the responsibility of
maintaining some kind of backward compatibility.

> I agree here. Yet to deny users a chance to use the best 
> current existing practice merely because something better
> is coming is IMO, a poor choice for rejecting this library.

Rejection is not the same as denying users the chance to use the
library.

[LL is accepted now, and over time, the scope is increased]
> I'd go with #2. The same way we are doing with "Threads." It 
> works, let people use it. Add functional programming to it if
> you want it, see how that works. If you _REALLY_ like it and 
> use it, add it, propose a new one etc.
> 
> Lambda may be fairly mature, but it is not static. We can 
> always push out a version 2.

The whole question is a question of the timeframe. When do we
realistically think that a better alternative will be available?

If it turns out, as Peter Dimov suggested, that it is easy to add for
instance scoping to LL, and correspondingly adopt some of the other
ideas from the competitors, I think it is an honourable to say: Ok,
something new has come up, and we will take a time out for a few months
until we assimilate the new technology, because this could have a very
significant impact.

And looking from the outside, the other alternative scenario is that
Joel is moving so fast on his own that he will be ready with Phoenix
within a few months.

If any of these scenarios are realistic, then it seems to be that it
could pay off to hold the horse for this timeframe.

Now, you respond: It will happen faster if you help. This is only fair.
But I'm afraid that I do not have the skills and the time to really help
out. As a poor excuse, I'm also tied to VC6, and thus I'll have a hard
time to contribute.

[Weak arity]
> This is under discussion between others on this thread, and 
> so far I haven't seen a convincing argument.

The main argument I have is that it is not symmetric:

(_2)(2, 3) is OK, but (_1)(2, 3) is not.

This seems a bit arbitrary to me.

Greets,

Asger Alstrup Nielsen