Improve RangeChip with tagged table

ecc/src/base_field_ecc.rs

@@ -421,8 +421,7 @@ mod tests {
 
         fn config_range<N: FieldExt>(&self, layouter: &mut impl Layouter<N>) -> Result<(), Error> {
             let range_chip = RangeChip::<N>::new(self.range_config.clone());
-            range_chip.load_composition_tables(layouter)?;
-            range_chip.load_overflow_tables(layouter)?;
+            range_chip.load_table(layouter)?;
 
             Ok(())
         }

ecc/src/general_ecc.rs

@@ -492,8 +492,7 @@ mod tests {
 
         fn config_range<N: FieldExt>(&self, layouter: &mut impl Layouter<N>) -> Result<(), Error> {
             let range_chip = RangeChip::<N>::new(self.range_config.clone());
-            range_chip.load_composition_tables(layouter)?;
-            range_chip.load_overflow_tables(layouter)?;
+            range_chip.load_table(layouter)?;
 
             Ok(())
         }

ecdsa/src/ecdsa.rs

@@ -200,8 +200,7 @@ mod tests {
             layouter: &mut impl Layouter<N>,
         ) -> Result<(), Error> {
             let range_chip = RangeChip::<N>::new(self.range_config.clone());
-            range_chip.load_composition_tables(layouter)?;
-            range_chip.load_overflow_tables(layouter)?;
+            range_chip.load_table(layouter)?;
 
             Ok(())
         }

halo2wrong/src/lib.rs

@@ -8,6 +8,7 @@ pub mod utils;
 pub use halo2;
 pub use halo2::halo2curves as curves;
 
+#[derive(Debug)]
 pub struct RegionCtx<'a, F: FieldExt> {
     region: Region<'a, F>,
     offset: usize,

integer/src/chip.rs

@@ -703,8 +703,7 @@ mod tests {
 
         fn config_range<N: FieldExt>(&self, layouter: &mut impl Layouter<N>) -> Result<(), Error> {
             let range_chip = RangeChip::<N>::new(self.range_config.clone());
-            range_chip.load_composition_tables(layouter)?;
-            range_chip.load_overflow_tables(layouter)?;
+            range_chip.load_table(layouter)?;
 
             Ok(())
         }

maingate/src/instructions.rs

@@ -11,7 +11,6 @@ use crate::{
     AssignedCondition, AssignedValue, ColumnTags, MainGateColumn,
 };
 use halo2wrong::{
-    halo2::plonk::Selector,
     utils::{big_to_fe, decompose, fe_to_big, power_of_two},
     RegionCtx,
 };
@@ -1003,12 +1002,12 @@ pub trait MainGateInstructions<F: FieldExt, const WIDTH: usize>: Chip<F> {
     /// Assigns a new witness composed of given array of terms
     /// `result = constant + term_0 + term_1 + ... `
     /// where `term_i = a_i * q_i`
-    fn decompose<T: FnMut(bool) -> Vec<Selector>>(
+    fn decompose<T: FnMut(&mut RegionCtx<'_, F>, bool) -> Result<(), Error>>(
         &self,
         ctx: &mut RegionCtx<'_, F>,
         terms: &[Term<F>],
         constant: F,
-        mut fetch_tables: T,
+        mut enable_lookup: T,
     ) -> Result<(AssignedValue<F>, Vec<AssignedValue<F>>), Error> {
         assert!(!terms.is_empty(), "At least one term is expected");
 
@@ -1054,11 +1053,7 @@ pub trait MainGateInstructions<F: FieldExt, const WIDTH: usize>: Chip<F> {
                 CombinationOptionCommon::CombineToNextAdd(F::one())
             };
 
-            // Enable tables if there is any
-            let tables = fetch_tables(is_final);
-            for table in tables {
-                ctx.enable(table)?;
-            }
+            enable_lookup(ctx, is_final)?;
 
             let chunk_len = chunk.len();
             let mut combined = self.apply(
@@ -1098,7 +1093,7 @@ pub trait MainGateInstructions<F: FieldExt, const WIDTH: usize>: Chip<F> {
         constant: F,
     ) -> Result<AssignedValue<F>, Error> {
         assert!(!terms.is_empty(), "At least one term is expected");
-        let (composed, _) = self.decompose(ctx, terms, constant, |_| vec![])?;
+        let (composed, _) = self.decompose(ctx, terms, constant, |_, _| Ok(()))?;
 
         Ok(composed)
     }

maingate/src/main_gate.rs

@@ -84,6 +84,13 @@ pub struct MainGateConfig {
     pub(crate) instance: Column<Instance>,
 }
 
+impl MainGateConfig {
+    /// Returns advice columns of `MainGateConfig`
+    pub fn advices(&self) -> [Column<Advice>; WIDTH] {
+        [self.a, self.b, self.c, self.d, self.e]
+    }
+}
+
 /// MainGate implements instructions with [`MainGateConfig`]
 #[derive(Clone, Debug)]
 pub struct MainGate<F: FieldExt> {