Interesting article, Alexey!

But we are still eagerly waiting for the 2nd part, when we should expect it?

Sorry for any confusion created - that was only half-baked 1st April joke, as correctly pointed out by Evgeny. I do not have yet such marvelous compiler (with closures, only modern syntax allowed, etc.)!

Sorry! :)

Well, as all lambdas, they are not silver bullets for those looking for better performance, neither they bring any performance overhead. They are simple syntax sugar for keeping some context close to operation. Nothing magical, but nothing less

1st version of this post used C++ style for keeping captured variables, but our small, but agile "design committee" decided to change approach and to use closer to JavaScript syntax here (because it's more natural and wider known to ObjectScript programmers), so see updated post soon.

The shorter, not very much serious answer - #dim is recommended by COS Guidelines we used in our local community - COS Guidelines

[But well, whom am I tricking about - these rules written by myself, and it was my personal push to use this practice here]

Here is the longer question: I hate dynamic typing systems, they tend to break sooner, and they frequently complicate understanding for your team mates. #dim constructs was a small set forward in making COS less dynamic typed, and more static typed language. Originally it was created as a hint for Studio auto-complete, but we always understood that it could be reused for some sort of static analyser (if it would ever be created) which will help find some COS errors rather sooner, at the compile time (or around of compilation time). But these has never materialized  (at least it has not happened till last time I checked a couple of years ago). 

So, if we could not check something automatically, via analysers, we could enforce it manually via policy written to guidelines, and obligatory peer-review before commits...

Hear, hear :)


There are always good friends which make me know

From that I see in postinstall script the only you need to do with cache.reg - is to create directory, and give it proper permissions 755 mask, i.e.:

mkdir -p /usr/local/etc/cachesys/cache.reg
chmod 755 /usr/local/etc/cachesys/cache.reg
ccontrol create ...


Let me be crystal clear and honest - this is horrible

[I thought so more than 2 years ago when Max originally published this approach in Russian and still think so today]

When you write some code you write it not for yourself, not for being modern and trendy, you write it "for another guy" which will visit it tomorrow. You need to write it as simple as possible, using most obvious approach.

If you could write something using same or similar amount of code but without tricky macros then you have to write it simpler and without macros (as here) or without tricky iterators (as in Max case). This complexity just not worth a time your team will loss debugging such code.

Please, do  not get me wrong - I love JavaScript/TypeScript and all modern things. And would love to apply as expressive constructs as closures in JavaScript or lambdas in C++ (hmm). But they are not here (yet) in the ObjectScript. Many of us tried to lobby for closures addition for ages, but gods of COS had no interest in them.

Though, in my personal opinion, implemention of handy closure support would not be much harder than dotted DO statement (and might be based on the same VM token implementation). But I might be wrong in estimation of complexity.