Simple memoization library for rust
Find it on docs.rs.
Add this to your Cargo.toml:
toml
[dependencies]
memoise = "0.3"
And then, just add memoise attribute to functions you want to memoise:
```rust use memoise::memoise;
fn fib(n: i64) -> i64 { if n == 0 || n == 1 { return n; } fib(n - 1) + fib(n - 2) } ```
And you can call it normally:
rust
fn main() {
println!("{}", fib(45));
}
And run it:
```sh $ cargo build --release $ time cargo run --release -q 1134903170
real 0m0.039s user 0m0.000s sys 0m0.016s ```
If comment out memoise attribute, it will not be memoised.
rust
// #[memoise(n <= 100)]
fn fib(n: i64) -> i64 {
if n == 0 || n == 1 {
return n;
}
fib(n - 1) + fib(n - 2)
}
```sh $ cargo build --release $ time cargo run --release -q 1134903170
real 0m5.019s user 0m4.984s sys 0m0.016s ```
When no bounds for keys given, the cache table Vec will be allocated dynamically.
```rust use memoise::memoise;
// the cache table for n is dynamically allocated
fn fib(n: i64) -> i64 { if n == 0 || n == 1 { return n; } fib(n - 1) + fib(n - 2) } ```
_reset function frees allocated Vec.
rust
fib(42); // This allocates cache table for `0..n+1`
fib_reset();
memoise_map memoises a function by using BTreeMap.
It is suitable for keys are sparse.
```rust
fn fib(n: i64) -> i64 { if n == 0 || n == 1 { return n; } fib(n - 1) + fib(n - 2) } ```
_reset function also releases all allocated memory.
For more information, you can find a document on docs.rs.