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factorio-rs

Collections and iterators

Language reference for collections. Recipe-style walkthrough: Filter entity lists.

Vec and loops

Section titled “Vec and loops”
let mut list: Vec<i64> = Vec::new();
list.push(1);
for item in list {
    // ...
}
Rust Lua behaviour
Vec::new() {}
push / len / is_empty table.insert / # / # == 0
vec![...] Prefer Vec::new() + push. Builds expand vec! through alloc helpers that are not lowered yet.
for x in v ipairs(v) when v is typed Vec<_>; else unordered pairs(v)
for x in v.iter() / v.into_iter() ordered ipairs(v)
for i in start..end numeric for i = start, end - 1 do
for i in start..=end numeric for i = start, end do

map / filter / take / collect

Section titled “map / filter / take / collect”

Supported: range or Vec iteration, then .map(|x| ...), .filter(|x| ...), and/or .take(n), ending in .collect() / .collect::<Vec<_>>().

let mapped = (0..n).map(|i| i + 1).collect::<Vec<_>>();
let odds = (0..=n).iter().filter(|i| *i % 2 == 1).collect::<Vec<_>>();
let first_odds = (0..=n).filter(|i| *i % 2 == 1).take(5).collect::<Vec<_>>();
let both = values
    .iter()
    .map(|i| i + 1)
    .filter(|i| *i > 1)
    .collect::<Vec<_>>();

.iter() / .into_iter() on a range is optional (same as (0..=n).filter(...).collect()). .take(n) respects adapter order (e.g. .filter(...).take(5) keeps five passing elements). Lowers to an immediately invoked Lua function that builds a table.

Not supported: enumerate, flat_map, zip, standing .iter() without collect, and arbitrary Iterator trait objects.

Section titled “Related”