fold_map

Function fold_map 

Source
pub fn fold_map<'a, ClonableFnBrand: 'a + ClonableFn, Brand: Foldable, A: 'a + Clone, M: 'a + Monoid + Clone>(
    f: ApplyFn<'a, ClonableFnBrand, A, M>,
) -> ApplyFn<'a, ClonableFnBrand, Apply0L1T<Brand, A>, M>
Expand description

Maps values to a monoid and combines them.

Free function version that dispatches to the typeclass’ associated function.

The default implementation of fold_map is implemented in terms of fold_right, compose, append and empty where:

fold_map f = (fold_right ((compose append) f)) empty

§Type Signature

forall f a m. Foldable f, Monoid m => (a -> m) -> f a -> m

§Parameters

  • f: A function that converts from values into monoidal elements.
  • fa: A foldable structure containing values of type A.

§Returns

Final monoid obtained from the folding operation.

§Examples

use fp_library::{brands::{VecBrand, RcFnBrand}, functions::{fold_map, identity}};
use std::rc::Rc;

assert_eq!(
    fold_map::<RcFnBrand, VecBrand, _, String>(Rc::new(identity))(vec![
        "Hello, ".to_string(),
        "World!".to_string()
    ]),
    "Hello, World!"
);