Trait halo2_proofs::circuit::layouter::RegionLayouter

source · [−]
pub trait RegionLayouter<F: Field>: Debug {
    fn enable_selector<'v>(
        &'v mut self,
        annotation: &'v (dyn Fn() -> String + 'v),
        selector: &Selector,
        offset: usize
    ) -> Result<(), Error>;
    fn assign_advice<'v>(
        &'v mut self,
        annotation: &'v (dyn Fn() -> String + 'v),
        column: Column<Advice>,
        offset: usize,
        to: &'v mut (dyn FnMut() -> Value<Assigned<F>> + 'v)
    ) -> Result<Cell, Error>;
    fn assign_advice_from_constant<'v>(
        &'v mut self,
        annotation: &'v (dyn Fn() -> String + 'v),
        column: Column<Advice>,
        offset: usize,
        constant: Assigned<F>
    ) -> Result<Cell, Error>;
    fn assign_advice_from_instance<'v>(
        &mut self,
        annotation: &'v (dyn Fn() -> String + 'v),
        instance: Column<Instance>,
        row: usize,
        advice: Column<Advice>,
        offset: usize
    ) -> Result<(Cell, Value<F>), Error>;
    fn instance_value(
        &mut self,
        instance: Column<Instance>,
        row: usize
    ) -> Result<Value<F>, Error>;
    fn assign_fixed<'v>(
        &'v mut self,
        annotation: &'v (dyn Fn() -> String + 'v),
        column: Column<Fixed>,
        offset: usize,
        to: &'v mut (dyn FnMut() -> Value<Assigned<F>> + 'v)
    ) -> Result<Cell, Error>;
    fn constrain_constant(
        &mut self,
        cell: Cell,
        constant: Assigned<F>
    ) -> Result<(), Error>;
    fn constrain_equal(&mut self, left: Cell, right: Cell) -> Result<(), Error>;
}
Expand description

Helper trait for implementing a custom Layouter.

This trait is used for implementing region assignments:

ⓘ
impl<'a, F: FieldExt, C: Chip<F>, CS: Assignment<F> + 'a> Layouter<C> for MyLayouter<'a, C, CS> {
    fn assign_region(
        &mut self,
        assignment: impl FnOnce(Region<'_, F, C>) -> Result<(), Error>,
    ) -> Result<(), Error> {
        let region_index = self.regions.len();
        self.regions.push(self.current_gate);

        let mut region = MyRegion::new(self, region_index);
        {
            let region: &mut dyn RegionLayouter<F> = &mut region;
            assignment(region.into())?;
        }
        self.current_gate += region.row_count;

        Ok(())
    }
}

TODO: It would be great if we could constrain the columns in these types to be “logical” columns that are guaranteed to correspond to the chip (and have come from Chip::Config).

Required Methods

Enables a selector at the given offset.

Assign an advice column value (witness)

Assigns a constant value to the column advice at offset within this region.

The constant value will be assigned to a cell within one of the fixed columns configured via ConstraintSystem::enable_constant.

Returns the advice cell that has been equality-constrained to the constant.

Assign the value of the instance column’s cell at absolute location row to the column advice at offset within this region.

Returns the advice cell that has been equality-constrained to the instance cell, and its value if known.

Returns the value of the instance column’s cell at absolute location row.

Assigns a fixed value

Constrains a cell to have a constant value.

Returns an error if the cell is in a column where equality has not been enabled.

Constraint two cells to have the same value.

Returns an error if either of the cells is not within the given permutation.

Trait Implementations

Converts to this type from the input type.

Implementors