2x🦠🕺 -karlos- 🗺 @karlos@en.osm.town

What? WASM Wars?
https://twitter.com/assemblyscript/status/1419110937261449216?s=12

Things I found out while learning #rustlang : Even Rust may get ugly slow
if you to_vec() a really long array inside a really long for .ither();
just do it before the loop 🧐.

Astra & Vector - Kreuz-Impfung.
Noch 15 Tage bis zur Party

Things I found out while learning 🦀 #rustlang : Just r.t.f.m.
again, one chapter per week.
You may discover forgotten but usefull features of #rust.

Odd things I found out while learning 🦀 #rustlang :
This will NOT build:
positions.push(-x_meter);
positions.push(+y_meter);
^ expected expression
error: expected expression, found `+`
In my source code, I just wanted to express: x is inverted, y is not. But I can't.
"+y_meter" is not an expression ?!?!? It is!
Can I write an issue? Against what?

#rustlang 🦀 Philosophical?: Can I load a file/texture/OSM-tile/Game-level while the render cycle keeps running?
Yes, I can start a file loading in the render cycle. And I get a call-back. Inside it, I can println! and process the loaded data.
But how to get that data/result back in the render cycle main code? I even can't set a bool, declared in the main.rs 😩
Preferred, I would start the load in my OsmTile::new(x,y) struct/class and put the result in an Option struct variable.

#rustlang #help needed:

THIS WORKS:
for index in 0..shape_merges.len() {
let shape_merge = & mut shape_merges[index];
shape_merge.create_mesh();

THIS NOT:
for shape_merge in shape_merges.iter() {
shape_merge.create_mesh();

Should I ask questions at Stack Overflow or is ther a #rust forum / place?

Odd things I found out while learning 🦀 #rustlang :
for i in 0..9 { println!("count {}",i) }
will NOT count form 0 to 9 but form 0 to 8! 😲
(Not much mentioned in the doc)
It is not "to", its "in" but not "inside" as 1 to 8.
May be it's "into"? The usually nerdy computing thing?
It is very useful anyway because you can write: 0..list.len()

Odd things I found out while learning #rustlang :
Using if, the "then" and else may have a "return value". Nice:
If you create an object different in both branches, you return one, usable afterwards.

Odd things I found out while learning #rustlang :
main.rs | lib.rs are special: 'mod' all the sources you need in your module there.
And 'use' all sources you intend to use where you intend to use them.

While using and learning 🦀 #rustlang I experience errors and troubles.
But I never got lost, desperate or angry (as I am used to).
I always got help, by compiler hints, by documentation with examples
and most important, by the community.

Odd things I found out while learning #rustlang :
You may have multiple struct/class "constructors", not by shuffling the parameters.
You may use "new" and any other name! Because Rust class functionallity is barely "hidden" in the code. Pusch of the self is visible but by calling a method.

Odd things I found out while learning #rustlang :
The last expression in a function
is the return value;
and must not end with a semikolon. 🤪

#wien #openstreetmap

Checking #rustlang with #wasm and #WebGL / #OpenGL for a #OpenStreetMap project: Lots of hiccups to me as a newbie. Any help would be appreciated.
Like: How to debug (with #AtomIDE)