1 files changed, 30 insertions, 0 deletions
diff --git a/nfa/src/error.rs b/nfa/src/error.rs
new file mode 100644
index 0000000..6112878
--- /dev/null
+++ b/nfa/src/error.rs
@@ -0,0 +1,30 @@
+//! This file implements the error type for the crate.
+
+use graph::error::Error as GError;
+
+use std::fmt::{Display, Formatter};
+
+#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd)]
+pub enum Error {
+    UnknownNode(usize),
+    UnsupportedOperation,
+    Graph(GError),
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::UnknownNode(id) => write!(f, "unknown node: {id}"),
+            Error::UnsupportedOperation => write!(f, "unsupported operation"),
+            Error::Graph(e) => write!(f, "graph error: {e}"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}
+
+impl From<GError> for Error {
+    fn from(e: GError) -> Self {
+        Self::Graph(e)
+    }
+}