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Fixed Lexor to correctly generate reverse polish notation (#33)
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* Updated from NeonXP/MathExecutor

* Fixed function in () block issue
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phpfui authored Nov 26, 2018
1 parent aa12a41 commit d50b665
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Showing 3 changed files with 151 additions and 133 deletions.
7 changes: 4 additions & 3 deletions README.md
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Expand Up @@ -3,18 +3,19 @@
A simple math expressions calculator

## Features:
* Built in support for +, -, *, / and power (^) operators
* Built in support for +, -, *, / and power (^) operators plus ()
* Support for user defined operators
* Support for user defined functions
* Unlimited varable length
* Unlimited varable name lengths
* String support, as function parameters or as evaluated by PHP
* Exceptions on divide by zero, or treat as zero
* Unary Minus
* Pi ($pi) and Euler's number ($e) support to 11 decimal places

## Install via Composer:
Stable branch
```
composer require "nxp/math-executor" "dev-master"
composer require "nxp/math-executor"
```

Dev branch (currently unsupported)
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263 changes: 133 additions & 130 deletions src/NXP/Classes/Lexer.php
Original file line number Diff line number Diff line change
@@ -1,130 +1,133 @@
<?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\Classes;
use NXP\Classes\Token\AbstractOperator;
use NXP\Classes\Token\InterfaceOperator;
use NXP\Classes\Token\TokenComma;
use NXP\Classes\Token\TokenFunction;
use NXP\Classes\Token\TokenLeftBracket;
use NXP\Classes\Token\TokenNumber;
use NXP\Classes\Token\TokenRightBracket;
use NXP\Classes\Token\TokenVariable;
use NXP\Classes\Token\TokenString;
use NXP\Exception\IncorrectBracketsException;
use NXP\Exception\IncorrectExpressionException;

/**
* @author Alexander Kiryukhin <[email protected]>
*/
class Lexer
{
/**
* @var TokenFactory
*/
private $tokenFactory;

public function __construct($tokenFactory)
{
$this->tokenFactory = $tokenFactory;
}

/**
* @param string $input Source string of equation
* @return array Tokens stream
* @throws \NXP\Exception\IncorrectExpressionException
*/
public function stringToTokensStream($input)
{
$matches = [];
preg_match_all($this->tokenFactory->getTokenParserRegex(), $input, $matches);
$tokenFactory = $this->tokenFactory;
$tokensStream = array_map(
function ($token) use ($tokenFactory) {
return $tokenFactory->createToken($token);
},
$matches[0]
);

return $tokensStream;
}

/**
* @param array $tokensStream Tokens stream
* @return array Array of tokens in revers polish notation
* @throws \NXP\Exception\IncorrectExpressionException
*/
public function buildReversePolishNotation($tokensStream)
{
$output = [];
$stack = [];

foreach ($tokensStream as $token) {
if ($token instanceof TokenString) {
$output[] = $token;
}
if ($token instanceof TokenNumber) {
$output[] = $token;
}
if ($token instanceof TokenVariable) {
$output[] = $token;
}
if ($token instanceof TokenFunction) {
array_push($stack, $token);
}
if ($token instanceof TokenLeftBracket) {
array_push($stack, $token);
}
if ($token instanceof TokenComma) {
while (($current = array_pop($stack)) && (!$current instanceof TokenLeftBracket)) {
$output[] = $current;
if (empty($stack)) {
throw new IncorrectExpressionException();
}
}
}
if ($token instanceof TokenRightBracket) {
while (($current = array_pop($stack)) && (!$current instanceof TokenLeftBracket)) {
$output[] = $current;
}
if (!empty($stack) && ($stack[count($stack)-1] instanceof TokenFunction)) {
$output[] = array_pop($stack);
}
}

if ($token instanceof AbstractOperator) {
while (
count($stack) > 0 &&
($stack[count($stack)-1] instanceof InterfaceOperator) &&
((
$token->getAssociation() == AbstractOperator::LEFT_ASSOC &&
$token->getPriority() <= $stack[count($stack)-1]->getPriority()
) || (
$token->getAssociation() == AbstractOperator::RIGHT_ASSOC &&
$token->getPriority() < $stack[count($stack)-1]->getPriority()
))
) {
$output[] = array_pop($stack);
}

array_push($stack, $token);
}
}
while (!empty($stack)) {
$token = array_pop($stack);
if ($token instanceof TokenLeftBracket || $token instanceof TokenRightBracket) {
throw new IncorrectBracketsException();
}
$output[] = $token;
}

return $output;
}
}
<?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\Classes;

use NXP\Classes\Token\AbstractOperator;
use NXP\Classes\Token\InterfaceOperator;
use NXP\Classes\Token\TokenComma;
use NXP\Classes\Token\TokenFunction;
use NXP\Classes\Token\TokenLeftBracket;
use NXP\Classes\Token\TokenNumber;
use NXP\Classes\Token\TokenRightBracket;
use NXP\Classes\Token\TokenVariable;
use NXP\Classes\Token\TokenString;
use NXP\Exception\IncorrectBracketsException;
use NXP\Exception\IncorrectExpressionException;

/**
* @author Alexander Kiryukhin <[email protected]>
*/
class Lexer
{
/**
* @var TokenFactory
*/
private $tokenFactory;

public function __construct($tokenFactory)
{
$this->tokenFactory = $tokenFactory;
}

/**
* @param string $input Source string of equation
* @return array Tokens stream
* @throws \NXP\Exception\IncorrectExpressionException
*/
public function stringToTokensStream($input)
{
$matches = [];
preg_match_all($this->tokenFactory->getTokenParserRegex(), $input, $matches);
$tokenFactory = $this->tokenFactory;
$tokensStream = array_map(
function ($token) use ($tokenFactory) {
return $tokenFactory->createToken($token);
},
$matches[0]
);

return $tokensStream;
}

/**
* @param array $tokensStream Tokens stream
* @return array Array of tokens in revers polish notation
* @throws \NXP\Exception\IncorrectExpressionException
*/
public function buildReversePolishNotation($tokensStream)
{
$output = [];
$stack = [];

foreach ($tokensStream as $token) {
if ($token instanceof TokenString) {
$output[] = $token;
}
elseif ($token instanceof TokenNumber) {
$output[] = $token;
}
elseif ($token instanceof TokenVariable) {
$output[] = $token;
}
elseif ($token instanceof TokenFunction) {
array_push($stack, $token);
}
elseif ($token instanceof AbstractOperator) {
// While we have something on the stack
while (($count = count($stack)) > 0
&& (
// If it is a function
($stack[$count-1] instanceof TokenFunction)

||
// Or the operator at the top of the operator stack
// has (left associative and equal precedence)
// or has greater precedence
(($stack[$count-1] instanceof InterfaceOperator) &&
(
($stack[$count-1]->getAssociation() == AbstractOperator::LEFT_ASSOC &&
$token->getPriority() == $stack[$count-1]->getPriority())
||
($stack[$count-1]->getPriority() > $token->getPriority())
)
)
)

// And not a left bracket
&& ( ! ($stack[$count-1] instanceof TokenLeftBracket)) ) {
$output[] = array_pop($stack);
}

array_push($stack, $token);
}
elseif ($token instanceof TokenLeftBracket) {
array_push($stack, $token);
}
elseif ($token instanceof TokenRightBracket) {
while (($current = array_pop($stack)) && ( ! ($current instanceof TokenLeftBracket))) {
$output[] = $current;
}
if (!empty($stack) && ($stack[count($stack)-1] instanceof TokenFunction)) {
$output[] = array_pop($stack);
}
}
}
while (!empty($stack)) {
$token = array_pop($stack);
if ($token instanceof TokenLeftBracket || $token instanceof TokenRightBracket) {
throw new IncorrectBracketsException();
}
$output[] = $token;
}

return $output;
}
}
14 changes: 14 additions & 0 deletions tests/MathTest.php
Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,21 @@ public function providerExpressions()
['(2 + 2)*-2'],
['(2+-2)*2'],

['1 + 2 * 3 / (min(1, 5) + 2 + 1)'],
['1 + 2 * 3 / (min(1, 5) - 2 + 5)'],
['1 + 2 * 3 / (min(1, 5) * 2 + 1)'],
['1 + 2 * 3 / (min(1, 5) / 2 + 1)'],
['1 + 2 * 3 / (min(1, 5) / 2 * 1)'],
['1 + 2 * 3 / (min(1, 5) / 2 / 1)'],
['1 + 2 * 3 / (3 + min(1, 5) + 2 + 1)'],
['1 + 2 * 3 / (3 - min(1, 5) - 2 + 1)'],
['1 + 2 * 3 / (3 * min(1, 5) * 2 + 1)'],
['1 + 2 * 3 / (3 / min(1, 5) / 2 + 1)'],


['sin(10) * cos(50) / min(10, 20/2)'],
['sin(10) * cos(50) / min(10, (20/2))'],
['sin(10) * cos(50) / min(10, (max(10,20)/2))'],

['100500 * 3.5E5'],
['100500 * 3.5E-5'],
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