Crate mdnt_groups_support 

mdnt-groups-support

Support traits for the picus::group macro.

This crate defines the DecomposeIn trait. This trait enables decomposing a complex type into an iterator of simple types. It is meant to be used with something like halo2_proofs::circuit::Cell but the trait is parametric.

Example

use mdnt_groups_support::DecomposeIn;

#[derive(Debug,Copy,Clone,Eq,PartialEq)]
struct Cell(usize);

// The base type needs to implement the trait 
impl DecomposeIn<Cell> for Cell {
    fn cells(&self) -> impl IntoIterator<Item = Cell> {
        std::iter::once(*self)
    }
}

struct A {
    cells: [Cell; 2],
}

impl DecomposeIn<Cell> for A {
    fn cells(&self) -> impl IntoIterator<Item = Cell> {
        // Some standard types come with implementations.
        self.cells.cells()
    }
}

struct B {
    a: A,
    cell: Cell
}

impl DecomposeIn<Cell> for B {
    fn cells(&self) -> impl IntoIterator<Item = Cell> {
        self.a.cells().into_iter().chain([self.cell])
    }
}

let b = B {
    a: A {
        cells: [Cell(2), Cell(8)]
    },
    cell: Cell(15)
};
let cells = b.cells().into_iter().collect::<Vec<_>>();
let flat = vec![Cell(2), Cell(8), Cell(15)];
assert_eq!(cells, flat);

Includes some implementations of the DecomposeIn<Cell> trait for standard types but is not exhaustive. The implemented types cover the needs of the circuits crate.

If other external types are required their implementation should be added to this crate.

Traits

DecomposeIn

Implementations of this trait represent complex types that aggregate a collection of AssignedCell values.