From 43f0ff3f28d198fbb4e36346fc5f36fa91cf3e18 Mon Sep 17 00:00:00 2001
From: Bruce Wells <phpfui@users.noreply.github.com>
Date: Thu, 25 Oct 2018 11:54:54 -0400
Subject: Support for better invalid expression detection and divide by zero
(#30)
* Additional validation for bad expressions (*+ for example)
* Removing DivisionByZeroException testing for now
Added more unit tests.
---
src/NXP/Classes/Calculator.php | 2 +-
src/NXP/Classes/Token/TokenDegree.php | 10 ++++++++++
src/NXP/Classes/Token/TokenDivision.php | 12 ++++++++++++
src/NXP/Classes/Token/TokenMinus.php | 10 ++++++++++
src/NXP/Classes/Token/TokenMultiply.php | 10 ++++++++++
src/NXP/Classes/Token/TokenPlus.php | 10 ++++++++++
src/NXP/Exception/DivisionByZeroException.php | 19 +++++++++++++++++++
7 files changed, 72 insertions(+), 1 deletion(-)
create mode 100644 src/NXP/Exception/DivisionByZeroException.php
(limited to 'src')
diff --git a/src/NXP/Classes/Calculator.php b/src/NXP/Classes/Calculator.php
index bfa7015..253e70c 100644
--- a/src/NXP/Classes/Calculator.php
+++ b/src/NXP/Classes/Calculator.php
@@ -54,7 +54,7 @@ class Calculator
}
}
$result = array_pop($stack);
- if (!empty($stack)) {
+ if ($result === null || ! empty($stack)) {
throw new IncorrectExpressionException();
}
diff --git a/src/NXP/Classes/Token/TokenDegree.php b/src/NXP/Classes/Token/TokenDegree.php
index c31b66e..3eec23d 100644
--- a/src/NXP/Classes/Token/TokenDegree.php
+++ b/src/NXP/Classes/Token/TokenDegree.php
@@ -10,6 +10,8 @@
namespace NXP\Classes\Token;
+use NXP\Exception\IncorrectExpressionException;
+
/**
* @author Alexander Kiryukhin <alexander@symdev.org>
*/
@@ -41,12 +43,20 @@ class TokenDegree extends AbstractOperator
/**
* @param InterfaceToken[] $stack
+ *
* @return TokenNumber
+ *
+ * @throws \NXP\Exception\IncorrectExpressionException
*/
public function execute(&$stack)
{
$op2 = array_pop($stack);
$op1 = array_pop($stack);
+
+ if ($op1 === null || $op2 === null) {
+ throw new IncorrectExpressionException("Power operator requires two operators");
+ }
+
$result = $op1->getValue() ** $op2->getValue();
return new TokenNumber($result);
diff --git a/src/NXP/Classes/Token/TokenDivision.php b/src/NXP/Classes/Token/TokenDivision.php
index f1c35ff..5bbc35e 100644
--- a/src/NXP/Classes/Token/TokenDivision.php
+++ b/src/NXP/Classes/Token/TokenDivision.php
@@ -10,6 +10,9 @@
namespace NXP\Classes\Token;
+use NXP\Exception\IncorrectExpressionException;
+use NXP\Exception\DivisionByZeroException;
+
/**
* @author Alexander Kiryukhin <alexander@symdev.org>
*/
@@ -41,12 +44,21 @@ class TokenDivision extends AbstractOperator
/**
* @param InterfaceToken[] $stack
+ *
* @return $this
+ *
+ * @throws \NXP\Exception\IncorrectExpressionException
+ * @throws \NXP\Exception\DivisionByZeroException
*/
public function execute(&$stack)
{
$op2 = array_pop($stack);
$op1 = array_pop($stack);
+
+ if ($op1 === null || $op2 === null) {
+ throw new IncorrectExpressionException("Division requires two operators");
+ }
+
$result = $op2->getValue() != 0 ? $op1->getValue() / $op2->getValue() : 0;
return new TokenNumber($result);
diff --git a/src/NXP/Classes/Token/TokenMinus.php b/src/NXP/Classes/Token/TokenMinus.php
index 0463d4c..566c950 100644
--- a/src/NXP/Classes/Token/TokenMinus.php
+++ b/src/NXP/Classes/Token/TokenMinus.php
@@ -10,6 +10,8 @@
namespace NXP\Classes\Token;
+use NXP\Exception\IncorrectExpressionException;
+
/**
* @author Alexander Kiryukhin <alexander@symdev.org>
*/
@@ -41,12 +43,20 @@ class TokenMinus extends AbstractOperator
/**
* @param InterfaceToken[] $stack
+ *
* @return $this
+ *
+ * @throws \NXP\Exception\IncorrectExpressionException
*/
public function execute(&$stack)
{
$op2 = array_pop($stack);
$op1 = array_pop($stack);
+
+ if ($op1 === null || $op2 === null) {
+ throw new IncorrectExpressionException("Subtraction requires two operators");
+ }
+
$result = $op1->getValue() - $op2->getValue();
return new TokenNumber($result);
diff --git a/src/NXP/Classes/Token/TokenMultiply.php b/src/NXP/Classes/Token/TokenMultiply.php
index e6fd960..8b173b9 100644
--- a/src/NXP/Classes/Token/TokenMultiply.php
+++ b/src/NXP/Classes/Token/TokenMultiply.php
@@ -10,6 +10,8 @@
namespace NXP\Classes\Token;
+use NXP\Exception\IncorrectExpressionException;
+
/**
* @author Alexander Kiryukhin <alexander@symdev.org>
*/
@@ -41,12 +43,20 @@ class TokenMultiply extends AbstractOperator
/**
* @param InterfaceToken[] $stack
+ *
* @return $this
+ *
+ * @throws \NXP\Exception\IncorrectExpressionException
*/
public function execute(&$stack)
{
$op2 = array_pop($stack);
$op1 = array_pop($stack);
+
+ if ($op1 === null || $op2 === null) {
+ throw new IncorrectExpressionException("Multiplication requires two operators");
+ }
+
$result = $op1->getValue() * $op2->getValue();
return new TokenNumber($result);
diff --git a/src/NXP/Classes/Token/TokenPlus.php b/src/NXP/Classes/Token/TokenPlus.php
index f9562e7..fe5a1d6 100644
--- a/src/NXP/Classes/Token/TokenPlus.php
+++ b/src/NXP/Classes/Token/TokenPlus.php
@@ -10,6 +10,8 @@
namespace NXP\Classes\Token;
+use NXP\Exception\IncorrectExpressionException;
+
/**
* @author Alexander Kiryukhin <alexander@symdev.org>
*/
@@ -41,12 +43,20 @@ class TokenPlus extends AbstractOperator
/**
* @param InterfaceToken[] $stack
+ *
* @return $this
+ *
+ * @throws \NXP\Exception\IncorrectExpressionException
*/
public function execute(&$stack)
{
$op2 = array_pop($stack);
$op1 = array_pop($stack);
+
+ if ($op1 === null || $op2 === null) {
+ throw new IncorrectExpressionException("Addition requires two operators");
+ }
+
$result = $op1->getValue() + $op2->getValue();
return new TokenNumber($result);
diff --git a/src/NXP/Exception/DivisionByZeroException.php b/src/NXP/Exception/DivisionByZeroException.php
new file mode 100644
index 0000000..3a9a978
--- /dev/null
+++ b/src/NXP/Exception/DivisionByZeroException.php
@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * This file is part of the MathExecutor package
+ *
+ * (c) Alexander Kiryukhin
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code
+ */
+
+namespace NXP\Exception;
+
+/**
+ * @author Vitaliy Zhuk <zhuk2205@gmail.com>
+ */
+class DivisionByZeroException extends MathExecutorException
+{
+}
--
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