feat(acir): add method on Circuit to return assert message

acir/src/circuit/mod.rs

@@ -40,6 +40,17 @@
     pub assert_messages: Vec<(OpcodeLocation, String)>,
 }
 
+impl Circuit {
+    /// Returns the assert message associated with the provided [`OpcodeLocation`].
+    /// Returns `None` if no such assert message exists.
+    pub fn get_assert_message(&self, opcode_location: OpcodeLocation) -> Option<&str> {
+        self.assert_messages
+            .iter()
+            .find(|(loc, _)| *loc == opcode_location)
+            .map(|(_, message)| message.as_str())
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
 /// Opcodes are locatable so that callers can
 /// map opcodes to debug information related to their context.
@@ -114,7 +125,7 @@
         PublicInputs(public_inputs)
     }
 
     #[cfg(feature = "serialize-messagepack")]
     pub fn write<W: std::io::Write>(&self, writer: W) -> std::io::Result<()> {
         let buf = rmp_serde::to_vec(&self).unwrap();
         let mut deflater = flate2::write::DeflateEncoder::new(writer, Compression::best());
@@ -122,7 +133,7 @@
 
         Ok(())
     }
     #[cfg(feature = "serialize-messagepack")]
     pub fn read<R: std::io::Read>(reader: R) -> std::io::Result<Self> {
         let mut deflater = flate2::read::DeflateDecoder::new(reader);
         let mut buf_d = Vec::new();
@@ -131,21 +142,21 @@
         Ok(circuit)
     }
 
     #[cfg(not(feature = "serialize-messagepack"))]
     pub fn write<W: std::io::Write>(&self, writer: W) -> std::io::Result<()> {
         let buf = bincode::serialize(&self).unwrap();
         let mut encoder = flate2::write::GzEncoder::new(writer, Compression::default());
         encoder.write_all(&buf).unwrap();
         encoder.finish().unwrap();
         Ok(())
     }
 
     #[cfg(not(feature = "serialize-messagepack"))]
     pub fn read<R: std::io::Read>(reader: R) -> std::io::Result<Self> {
         let mut gz_decoder = flate2::read::GzDecoder::new(reader);
         let mut buf_d = Vec::new();
         gz_decoder.read_to_end(&mut buf_d).unwrap();
         let circuit = bincode::deserialize(&buf_d).unwrap();
         Ok(circuit)
     }
 }