Merge pull request #27 from nnao45/codex/refactor-dntker.rs-for-size

refactor bc runtime layering

Author: nnao45

src/dntker/bc/bc.rs

@@ -0,0 +1,17 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub enum BcError {
+    NoResult,
+    /// Parse or evaluation error
+    Error(String),
+}
+
+impl fmt::Display for BcError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            BcError::NoResult => write!(f, "No result returned"),
+            BcError::Error(msg) => write!(f, "Evaluation error: {msg}"),
+        }
+    }
+}