Struct FoldDef

pub struct FoldDef { /* private fields */ }

Definition of a “fold” function.

The “fold” function is similar to the “fold” function in stdlib. It takes an initial state, processes new entries, then output the new state.

Given an append-only Log, the state of a “fold” function can be saved to disk and loaded later. A Log maintains the on-disk state so “fold” calculation won’t always start from scratch.

Implementations

impl FoldDef

pub fn new(name: &'static str, create_fold: fn() -> Box<dyn Fold>) -> Self

Create a “fold” definition.

create_func is a function to produce an empty “fold” state.

Trait Implementations

impl Clone for FoldDef

fn clone(&self) -> FoldDef

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FoldDef

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.