Move graph error to its own module.

src/graph_error.rs

@@ -0,0 +1,32 @@
+//
+// Copyright 2023 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+use alloc::string::{String, ToString};
+
+#[derive(Debug, Clone)]
+pub struct GraphError {
+    pub msg: String,
+}
+
+impl GraphError {
+    pub fn from_msg(msg: &str) -> Self {
+        GraphError {
+            msg: msg.to_string(),
+        }
+    }
+}
+
+impl core::fmt::Display for GraphError {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        write!(f, "Error manipulating graph: {}", self.msg)
+    }
+}
+
+impl core::error::Error for GraphError {}

src/lib.rs

@@ -11,12 +11,13 @@
 #![no_std]
 extern crate alloc;
 mod node;
+mod graph_error;
 
 use alloc::collections::vec_deque::VecDeque;
-use alloc::string::{String, ToString};
 use alloc::vec;
 use alloc::vec::Vec;
 pub use node::*;
+pub use graph_error::*;
 
 /// A generic graph type holding values connected to other values.
 /// Values can be added to the graph, but not removed.
@@ -145,27 +146,6 @@ impl<NodeValueT: NodeValue> Graph<NodeValueT> {
     }
 }
 
-#[derive(Debug, Clone)]
-pub struct GraphError {
-    pub msg: String,
-}
-
-impl GraphError {
-    pub fn from_msg(msg: &str) -> Self {
-        GraphError {
-            msg: msg.to_string(),
-        }
-    }
-}
-
-impl core::fmt::Display for GraphError {
-    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
-        write!(f, "Error manipulating graph: {}", self.msg)
-    }
-}
-
-impl core::error::Error for GraphError {}
-
 #[cfg(test)]
 mod tests {
     use super::*;