rpn(1): fixed Invalid error handling

src/rpn.rs

@@ -56,7 +56,7 @@ extern crate sysexits;
 
 use sysexits::EX_DATAERR;
 
-#[derive(Clone, Copy, PartialEq, PartialOrd, Debug)]
+#[derive(Clone, PartialEq, PartialOrd, Debug)]
 // enum CalcType is a type containing operations used in the calculator
 enum CalcType {
 	Add,
@@ -67,7 +67,7 @@ enum CalcType {
 	Floor,
 	Modulo,
 	Val(f64),
-	Invalid,
+	Invalid(String),
 }
 
 impl From<&str> for CalcType {
@@ -83,7 +83,7 @@ impl From<&str> for CalcType {
 			_ => {
 				match value.parse::<f64>() {
 					Ok(x) => Val(x),
-					Err(_) => Invalid,
+					Err(_) => Invalid(value.to_owned()),
 				}
 			},
 		}
@@ -104,7 +104,9 @@ impl Display for CalcType {
 			Val(x) => {
 				y = x.to_string(); &y
 			},
-			Invalid => "",
+			Invalid(i) => {
+				y = i.to_string(); &y
+			},
 		})
 	}
 }
@@ -146,13 +148,13 @@ fn eval(
 	while let Some(n) = toks.pop_back() {
 		match n {
 			Val(v) => stack.push_back(v),
-			Invalid => {
+			Invalid(i) => {
 				return Err(EvaluationError {
-					message: format!("{}: Invalid token", n)
+					message: format!("{}: Invalid token", i)
 				})
 			},
 			op => {
-				ops.push_back(op);
+				ops.push_back(op.clone());
 				oper = true;
 
 				let vals = (