rpn(1): made EvaluationError struct contain exit code

src/rpn.rs

@@ -112,19 +112,15 @@ impl Display for CalcType {
 }
 
 #[derive(Debug, Clone)]
-struct EvaluationError { pub message: String }
-
-impl Display for EvaluationError {
-	fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-		write!(f, "{}", self.message)
-	}
+struct EvaluationError {
+	message: String,
+	code: i32,
 }
 
 // I’m no math nerd but I want the highest possible approximation of 0.9
 // repeating and it seems this can give it to me
 const PRECISION_MOD: f64 = 0.9 + f64::EPSILON * 100.0;
 
-
 fn eval(
 	input: &str,
 	initial_stack: VecDeque<f64>,
@@ -150,7 +146,8 @@ fn eval(
 			Val(v) => stack.push_back(v),
 			Invalid(i) => {
 				return Err(EvaluationError {
-					message: format!("{}: Invalid token", i)
+					message: format!("{}: Invalid token", i),
+					code: EX_DATAERR,
 				})
 			},
 			op => {
@@ -175,7 +172,8 @@ fn eval(
 					};
 				} else {
 					return Err(EvaluationError {
-						message: format!("{}: Unexpected operation.", op)
+						message: format!("{}: Unexpected operation.", op),
+						code: EX_DATAERR,
 					})
 				}
 			},
@@ -217,7 +215,7 @@ fn main() -> ExitCode {
 				},
 				Err(err) => {
 					eprintln!("{}: {}", argv[0], err.message);
-					return ExitCode::from(EX_DATAERR as u8);
+					return ExitCode::from(err.code as u8);
 				},
 			};
 		}
@@ -242,7 +240,7 @@ fn main() -> ExitCode {
 			},
 			Err(err) => {
 				eprintln!("{}: {}", argv[0], err.message);
-				return ExitCode::from(EX_DATAERR as u8);
+				return ExitCode::from(err.code as u8);
 			},
 		};
 	}