dusky root
Hello. I'm trying to convert this simple TypeScript code to Rust:
const FRUITS = new Set(["apple", "banana"]);
function isFruit(thing: string): boolean {
return mySet.has(thing);
}
I tried asking ChatGPT, but it gave me a solution that was either using unsafe (which is bad) or using lazy_static (which is an extra dependency).
Is there not a simple way to do this code in Rust with just the standard library?
earnest pendant
HashSet in the standard lib is what you're looking for
autumn shoal
making a hashset in global contexts may be more difficult
if a given set is small enough i'd just use an array inside is_fruit and use contains
dusky root
Yes, I'm looking to just make a hash set that exists for the context of the entire program.
if a given set is small enough i'd just use an array inside is_fruit and use contains
Is that best practice? It won't be O(1) anymore, right?
autumn shoal
well, good thing OnceLock is stabilized, which means you could write this with less boilerplate than before, but still not good compared to using a phf or a Lazy from once_cell
autumn shoal
> if a given set is small enough i'd just use an array inside is_fruit and use c...
the cost of hashing would be greater
autumn shoal
depends on the type, but i usually see ppl say around a 100
?play
remote rapids
use std::sync::OnceLock;
use std::collections::HashSet;
static FRUITS: OnceLock<HashSet<&'static str>> = OnceLock::new();
fn fruits_init() -> HashSet<&'static str> {
HashSet::from(["apple", "banana"])
}
fn is_fruit(thing: &str) -> bool {
FRUITS.get_or_init(fruits_init).contains(thing)
}
marsh spokeBOT
autumn shoal
this is a translation of ur code, assuming you don't want dependencies
if you are open to dependencies, you could use once_cell
dusky root
Thank you, but I'll take your advice and just use a simple array for now, since I don't expect that the array will ever grow to larger than 100 elements.
autumn shoal
?play
use once_cell::sync::Lazy;
use std::collections::HashSet;
static FRUITS: Lazy<HashSet<&'static str>> = Lazy::new(|| HashSet::from(["apple", "banana"]));
fn is_fruit(thing: &str) -> bool {
FRUITS.contains(thing)
}
tough tundra
Hello. I'm trying to convert this simple TypeScript code to Rust:
```ts
const FR...
static FRUITS: &[&str] = &["apple", "banana"];
fn is_fruit(maybe_fruit: &str) -> bool {
FRUITS.contains(maybe_fruit)
}