feat: public cells to allow for implementations of custom Layouter

halo2_gadgets/src/poseidon/primitives/mds.rs

@@ -81,8 +81,9 @@ pub(super) fn generate_mds<F: FromUniformBytes<64> + Ord, const T: usize>(
             if m == j {
                 acc
             } else {
+                let diff: F = x_j - *x_m;
                 // We can invert freely; by construction, the elements of xs are distinct.
-                acc * (x - x_m) * (x_j - x_m).invert().unwrap()
+                acc * (x - x_m) * diff.invert().unwrap()
             }
         })
     };

halo2_proofs/src/circuit.rs

@@ -13,6 +13,7 @@ pub use value::Value;
 
 pub mod floor_planner;
 pub use floor_planner::single_pass::SimpleFloorPlanner;
+pub use floor_planner::single_pass::SimpleTableLayouter;
 
 pub mod layouter;
 
@@ -87,11 +88,11 @@ impl std::ops::Deref for RegionStart {
 #[derive(Clone, Copy, Debug)]
 pub struct Cell {
     /// Identifies the region in which this cell resides.
-    region_index: RegionIndex,
+    pub region_index: RegionIndex,
     /// The relative offset of this cell within its region.
-    row_offset: usize,
+    pub row_offset: usize,
     /// The column of this cell.
-    column: Column<Any>,
+    pub column: Column<Any>,
 }
 
 /// An assigned cell.

halo2_proofs/src/circuit/floor_planner/single_pass.rs

@@ -398,11 +398,12 @@ impl<'r, 'a, F: Field, CS: Assignment<F> + 'a + SyncDeps> RegionLayouter<F>
 ///   witnesses or not.
 type DefaultTableValue<F> = Option<Value<Assigned<F>>>;
 
-pub(crate) struct SimpleTableLayouter<'r, 'a, F: Field, CS: Assignment<F> + 'a> {
+/// A table layouter that can be used to assign values to a table.
+pub struct SimpleTableLayouter<'r, 'a, F: Field, CS: Assignment<F> + 'a> {
     cs: &'a mut CS,
     used_columns: &'r [TableColumn],
-    // maps from a fixed column to a pair (default value, vector saying which rows are assigned)
-    pub(crate) default_and_assigned: HashMap<TableColumn, (DefaultTableValue<F>, Vec<bool>)>,
+    /// maps from a fixed column to a pair (default value, vector saying which rows are assigned)
+    pub default_and_assigned: HashMap<TableColumn, (DefaultTableValue<F>, Vec<bool>)>,
 }
 
 impl<'r, 'a, F: Field, CS: Assignment<F> + 'a> fmt::Debug for SimpleTableLayouter<'r, 'a, F, CS> {
@@ -415,7 +416,8 @@ impl<'r, 'a, F: Field, CS: Assignment<F> + 'a> fmt::Debug for SimpleTableLayoute
 }
 
 impl<'r, 'a, F: Field, CS: Assignment<F> + 'a> SimpleTableLayouter<'r, 'a, F, CS> {
-    pub(crate) fn new(cs: &'a mut CS, used_columns: &'r [TableColumn]) -> Self {
+    ///
+    pub fn new(cs: &'a mut CS, used_columns: &'r [TableColumn]) -> Self {
         SimpleTableLayouter {
             cs,
             used_columns,

halo2_proofs/src/plonk/circuit.rs

@@ -577,7 +577,8 @@ pub struct TableColumn {
 }
 
 impl TableColumn {
-    pub(crate) fn inner(&self) -> Column<Fixed> {
+    /// Returns inner column
+    pub fn inner(&self) -> Column<Fixed> {
         self.inner
     }
 }