Implement std::fmt::Display for parser errors

src/parse.rs

@@ -9,6 +9,15 @@ pub enum Error {
 	InvalidSyntax,
 }
 
+impl std::fmt::Display for Error {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		match self {
+			Error::Io(err) => write!(f, "I/O Error: {}", err),
+			Error::InvalidSyntax => write!(f, "Invalid syntax"),
+		}
+	}
+}
+
 impl std::str::FromStr for Expression {
 	type Err = Error;