diff options
Diffstat (limited to 'src/main/java/sevenUnits/utils/ExpressionParser.java')
| -rw-r--r-- | src/main/java/sevenUnits/utils/ExpressionParser.java | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/main/java/sevenUnits/utils/ExpressionParser.java b/src/main/java/sevenUnits/utils/ExpressionParser.java index 1d3d44d..941c2a4 100644 --- a/src/main/java/sevenUnits/utils/ExpressionParser.java +++ b/src/main/java/sevenUnits/utils/ExpressionParser.java @@ -461,10 +461,12 @@ public final class ExpressionParser<T> { * * @param expression expression * @return expression in RPN + * @throws IllegalArgumentException if expression is invalid (e.g. + * "{@code 3 *}") * @since 2019-03-17 * @since v0.2.0 */ - private String convertExpressionToReversePolish(final String expression) { + String convertExpressionToReversePolish(final String expression) { Objects.requireNonNull(expression, "expression must not be null."); final List<String> components = new ArrayList<>(); @@ -541,6 +543,9 @@ public final class ExpressionParser<T> { switch (this .getTokenType(components.get(highestPriorityOperatorPosition))) { case UNARY_OPERATOR: + if (components.size() < 2) + throw new IllegalArgumentException( + "Invalid expression \"" + expression + "\""); final String unaryOperator = components .remove(highestPriorityOperatorPosition); final String operand = components @@ -549,6 +554,9 @@ public final class ExpressionParser<T> { operand + " " + unaryOperator); break; case BINARY_OPERATOR: + if (components.size() < 3) + throw new IllegalArgumentException( + "Invalid expression \"" + expression + "\""); final String binaryOperator = components .remove(highestPriorityOperatorPosition); final String operand1 = components @@ -672,7 +680,7 @@ public final class ExpressionParser<T> { * @since 2019-03-14 * @since v0.2.0 */ - private T parseReversePolishExpression(final String expression) { + T parseReversePolishExpression(final String expression) { Objects.requireNonNull(expression, "expression must not be null."); final Deque<T> stack = new ArrayDeque<>(); |