Discuss performance benefits of native types

[AlexDaniel]

From #372 (comment):

Native int, num and so on can be used to speed up thing, like shaped Array. They are not only useful with NC

[jnthn]

Not only speed things up, but natively typed arrays can be a giant memory saving also where applicable.

[AlexDaniel]

Where could this go? nativecall page is not exactly the right place. And as native types go, we only have int documented. After #372 all native types point to nativecall page but again that's not entirely right.

[jnthn]

The int documentation is somewhat unfortunate in that it lists a load of methods you can call on a "native int". This not quite true, as you can't call a method, or indeed do anything object-y, on a native type. Calls to such methods will box the native integer into an Int and the method will be called on that (one can observe this by trying (my int $x = 42).WHAT and observing it says Int, not int - the reason is that the int was boxed into Int to have something to ask for the type object of).

Perhaps making the native int documentation describe what a native integer is, the sized variants, and its boxing behavior (with a link to Int documentation) would be more useful?

[JJ]

I can think either of a new performance issues page or the already existing traps page.

[AlexDaniel]

@JJ no-no, I think this should go directly to the same place where native types are discussed. Unfortunately, I don't know about a page like this.

To clarify, a person searching for “int” should be able to eventually land on a page which discusses packed native arrays and stuff like that. And there we can say why the user may want to do that at all (e.g. for performance reasons).

[AlexDaniel]

Currently searching for int gives https://docs.perl6.org/type/nativeInt which says “TODO”. Not good at all :(

There's also https://docs.perl6.org/language/nativecall but that's a different topic IMO.

[zoffixznet]

FWIW the CaR grant branch that'll be merged after next release (2018-05-19) adds a "Numerics" language page that does mention native types as well as their performance benefits, including the case where they're lost because code does a lot of boxing.

[JJ]

Please close this issue then when you merge.