[−][src]Crate memor
An attribute macro to memoize function calls
Usage
Just add #[memo]
to your function.
use memor::memo; #[memo] fn fib(n: i64) -> i64 { if n == 0 || n == 1 { n } else { fib(n - 1) + fib(n - 2) } } assert_eq!(12586269025, fib(50));
Various functions can be memoized.
Because the arguments are saved into keys of std::collections::HashMap
internally,
this macro can be applied to functions all of whose arguments implments Hash
and Eq
.
use memor::memo; #[derive(Hash, Eq, PartialEq)] struct Foo { a: usize, b: usize, } #[memo] fn foo(Foo { a, b }: Foo, c: usize) -> usize { if a == 0 || b == 0 || c == 0 { 1 } else { foo(Foo { a, b: b - 1 }, c) .wrapping_add(foo(Foo { a: a - 1, b }, c)) .wrapping_add(foo(Foo { a, b }, c - 1)) } } assert_eq!(foo(Foo { a: 50, b: 50 }, 50), 6753084261833197057);
Attribute Macros
memo |