mirror of https://github.com/zcash/halo2.git
63 lines
1.9 KiB
Rust
63 lines
1.9 KiB
Rust
|
//! Implementations of common circuit layouters.
|
||
|
|
|
||
|
|
use std::fmt;
|
||
|
|
|
||
|
|
use super::{Cell, Chip, Permutation};
|
||
|
|
use crate::plonk::{Advice, Column, Error, Fixed};
|
||
|
|
|
||
|
|
/// Helper trait for implementing a custom [`Layouter`].
|
||
|
|
///
|
||
|
|
/// This trait is used for implementing region assignments:
|
||
|
|
///
|
||
|
|
/// ```ignore
|
||
|
|
/// impl<'a, C: Chip, CS: Assignment<C::Field> + 'a> Layouter<C> for MyLayouter<'a, C, CS> {
|
||
|
|
/// fn assign_region(
|
||
|
|
/// &mut self,
|
||
|
|
/// assignment: impl FnOnce(Region<'_, 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<C> = &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`).
|
||
|
|
pub trait RegionLayouter<C: Chip>: fmt::Debug {
|
||
|
|
/// Assign an advice column value (witness)
|
||
|
|
fn assign_advice<'v>(
|
||
|
|
&'v mut self,
|
||
|
|
column: Column<Advice>,
|
||
|
|
offset: usize,
|
||
|
|
to: &'v mut (dyn FnMut() -> Result<C::Field, Error> + 'v),
|
||
|
|
) -> Result<Cell, Error>;
|
||
|
|
|
||
|
|
/// Assign a fixed value
|
||
|
|
fn assign_fixed<'v>(
|
||
|
|
&'v mut self,
|
||
|
|
column: Column<Fixed>,
|
||
|
|
offset: usize,
|
||
|
|
to: &'v mut (dyn FnMut() -> Result<C::Field, Error> + 'v),
|
||
|
|
) -> Result<Cell, Error>;
|
||
|
|
|
||
|
|
/// Constraint two cells to have the same value.
|
||
|
|
///
|
||
|
|
/// Returns an error if either of the cells is not within the given permutation.
|
||
|
|
fn constrain_equal(
|
||
|
|
&mut self,
|
||
|
|
permutation: &Permutation,
|
||
|
|
left: Cell,
|
||
|
|
right: Cell,
|
||
|
|
) -> Result<(), Error>;
|
||
|
|
}
|