Rename Error::IncompatibleParams to Error::InvalidInstances

This was leftover from when proofs were structured in memory.

CHANGELOG.md

@@ -6,6 +6,10 @@ and this project adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- `halo2::plonk::Error` has been overhauled:
+  - `Error::IncompatibleParams` is now `Error::InvalidInstances`.
+
 ### Removed
 - `halo2::arithmetic::BatchInvert` (use `ff::BatchInvert` instead).
 

src/dev.rs

@@ -528,7 +528,7 @@ impl<F: FieldExt> MockProver<F> {
         }
 
         if instance.len() != cs.num_instance_columns {
-            return Err(Error::IncompatibleParams);
+            return Err(Error::InvalidInstances);
         }
 
         let instance = instance

src/plonk/error.rs

@@ -5,9 +5,8 @@ pub enum Error {
     /// This is an error that can occur during synthesis of the circuit, for
     /// example, when the witness is not present.
     SynthesisError,
-    /// The structured reference string or the parameters are not compatible
-    /// with the circuit being synthesized.
-    IncompatibleParams,
+    /// The provided instances do not match the circuit parameters.
+    InvalidInstances,
     /// The constraint system is not satisfied.
     ConstraintSystemFailure,
     /// Out of bounds index passed to a backend

src/plonk/prover.rs

@@ -43,7 +43,7 @@ pub fn create_proof<
 ) -> Result<(), Error> {
     for instance in instances.iter() {
         if instance.len() != pk.vk.cs.num_instance_columns {
-            return Err(Error::IncompatibleParams);
+            return Err(Error::InvalidInstances);
         }
     }
 

src/plonk/verifier.rs

@@ -24,7 +24,7 @@ pub fn verify_proof<'params, C: CurveAffine, E: EncodedChallenge<C>, T: Transcri
     // Check that instances matches the expected number of instance columns
     for instances in instances.iter() {
         if instances.len() != vk.cs.num_instance_columns {
-            return Err(Error::IncompatibleParams);
+            return Err(Error::InvalidInstances);
         }
     }