Throw error on expressions with too many operators

1 files changed, 4 insertions, 8 deletions

diff --git a/src/main/java/sevenUnits/utils/ExpressionParser.java b/src/main/java/sevenUnits/utils/ExpressionParser.java
index 2bc8952..4f9cfa8 100644
--- a/src/main/java/sevenUnits/utils/ExpressionParser.java
+++ b/src/main/java/sevenUnits/utils/ExpressionParser.java
@@ -684,15 +684,11 @@ public final class ExpressionParser<T> {
 
 		// join all of the components together, then ensure there is only one
 		// space in a row
-		String expressionRPN = String.join(" ", components).replaceAll(" +", " ");
-
-		while (expressionRPN.charAt(0) == ' ') {
-			expressionRPN = expressionRPN.substring(1);
-		}
-		while (expressionRPN.charAt(expressionRPN.length() - 1) == ' ') {
-			expressionRPN = expressionRPN.substring(0, expressionRPN.length() - 1);
+		if (components.size() != 1) {
+			throw new IllegalArgumentException(
+					"Invalid expression \"" + expression + "\".");
 		}
-		return expressionRPN;
+		return components.get(0).replaceAll(" +", " ").trim();
 	}
 
 	/**