1 unstable release
0.1.0 | Apr 21, 2024 |
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#1331 in Data structures
118 downloads per month
11KB
198 lines
FnMap
FnMap is a abstraction around the HashMap, like TypeMap. But uses closure's type(each closure's type is unique in Rust) as key and stores produced value. Allowing to be used like effective low cost dependency injection container.
Usage
use fn_map::FnMap;
let map = FnMap::new();
fn one() -> i32 {
println!("one computed");
1
}
// get or compute(and insert) value using given closure. The closure depends on value of `one` function to compute its output.
let a = *map.get(|| map.get(one) + 1);
dbg!(a);
// b is *not* a because each closure's type is unique
let b = *map.get(|| map.get(one) + 1);
dbg!(b);
// get or compute(and insert) value using give function. But will not compute since it is computed already when producing a.
let c = *map.get(one);
dbg!(c);
will output
one computed
a = 2
b = 2
c = 1
License
MIT
Dependencies
~2–8MB
~39K SLoC