Fix to PSR standart, fix tokenizer, fix function executor.

1 files changed, 393 insertions, 0 deletions

diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
new file mode 100644
index 0000000..482b4b7
--- /dev/null
+++ b/src/NXP/MathExecutor.php
@@ -0,0 +1,393 @@
+<?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;
+
+use NXP\Classes\Func;
+use NXP\Classes\Operand;
+use NXP\Classes\Token;
+use NXP\Classes\TokenParser;
+use NXP\Exception\IncorrectExpressionException;
+use NXP\Exception\UnknownFunctionException;
+use NXP\Exception\UnknownOperatorException;
+use NXP\Exception\UnknownTokenException;
+
+/**
+ * Class MathExecutor
+ * @package NXP
+ */
+class MathExecutor
+{
+    /**
+     * Available operators
+     *
+     * @var array
+     */
+    private $operators = array();
+
+    /**
+     * Available functions
+     *
+     * @var array
+     */
+    private $functions = array();
+
+    /**
+     * Available variables
+     *
+     * @var array
+     */
+    private $variables = array();
+
+    /**
+     * @var \SplStack
+     */
+    private $stack;
+
+    /**
+     * @var \SplQueue
+     */
+    private $queue;
+
+    /**
+     * Base math operators
+     */
+    public function __construct()
+    {
+        $this->addDefaults();
+    }
+
+    public function __clone()
+    {
+        $this->variables = array();
+        $this->operators = array();
+        $this->functions = array();
+
+        $this->addDefaults();
+    }
+
+    /**
+     * Set default operands and functions
+     */
+    protected function addDefaults()
+    {
+        $this->addOperator(new Operand('+', 1, Operand::LEFT_ASSOCIATED, Operand::BINARY, function ($op1, $op2) { return $op1+$op2; }));
+        $this->addOperator(new Operand('-', 1, Operand::LEFT_ASSOCIATED, Operand::BINARY, function ($op1, $op2) { return $op1-$op2; }));
+        $this->addOperator(new Operand('*', 2, Operand::LEFT_ASSOCIATED, Operand::BINARY, function ($op1, $op2) { return $op1*$op2; }));
+        $this->addOperator(new Operand('/', 2, Operand::LEFT_ASSOCIATED, Operand::BINARY, function ($op1, $op2) { return $op1/$op2; }));
+        $this->addOperator(new Operand('^', 3, Operand::LEFT_ASSOCIATED, Operand::BINARY, function ($op1, $op2) { return pow($op1,$op2); }));
+
+        $this->addFunction(new Func('sin',  function ($arg) { return sin($arg); }));
+        $this->addFunction(new Func('cos',  function ($arg) { return cos($arg); }));
+        $this->addFunction(new Func('tn',   function ($arg) { return tan($arg); }));
+        $this->addFunction(new Func('asin', function ($arg) { return asin($arg); }));
+        $this->addFunction(new Func('acos', function ($arg) { return acos($arg); }));
+        $this->addFunction(new Func('atn',  function ($arg) { return atan($arg); }));
+    }
+
+    /**
+     * Add operator to executor
+     *
+     * @param  Operand      $operator
+     * @return MathExecutor
+     */
+    public function addOperator(Operand $operator)
+    {
+        $this->operators[$operator->getSymbol()] = $operator;
+
+        return $this;
+    }
+
+    /**
+     * Add function to executor
+     *
+     * @param  string       $name
+     * @param  callable     $function
+     * @return MathExecutor
+     */
+    public function addFunction($name, callable $function = null)
+    {
+        if ($name instanceof Func) {
+            $this->functions[$name->getName()] = $name->getCallback();
+        } else {
+            $this->functions[$name] = $function;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Add variable to executor
+     *
+     * @param  string        $variable
+     * @param  integer|float $value
+     * @throws \Exception
+     * @return MathExecutor
+     */
+    public function setVar($variable, $value)
+    {
+        if (!is_numeric($value)) {
+            throw new \Exception("Variable value must be a number");
+        }
+
+        $this->variables[$variable] = $value;
+
+        return $this;
+    }
+
+    /**
+     * Add variables to executor
+     *
+     * @param  array        $variables
+     * @param  bool         $clear     Clear previous variables
+     * @return MathExecutor
+     */
+    public function setVars(array $variables, $clear = true)
+    {
+        if ($clear) {
+            $this->removeVars();
+        }
+
+        foreach ($variables as $name => $value) {
+            $this->setVar($name, $value);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Remove variable from executor
+     *
+     * @param  string       $variable
+     * @return MathExecutor
+     */
+    public function removeVar($variable)
+    {
+        unset ($this->variables[$variable]);
+
+        return $this;
+    }
+
+    /**
+     * Remove all variables
+     */
+    public function removeVars()
+    {
+        $this->variables = array();
+
+        return $this;
+    }
+
+    /**
+     * Execute expression
+     *
+     * @param $expression
+     * @return int|float
+     */
+    public function execute($expression)
+    {
+        $reversePolishNotation = $this->convertToReversePolishNotation($expression);
+        $result = $this->calculateReversePolishNotation($reversePolishNotation);
+
+        return $result;
+    }
+
+    /**
+     * Convert expression from normal expression form to RPN
+     *
+     * @param $expression
+     * @return \SplQueue
+     * @throws \Exception
+     */
+    private function convertToReversePolishNotation($expression)
+    {
+        $this->stack = new \SplStack();
+        $this->queue = new \SplQueue();
+
+        $tokenParser = new TokenParser();
+        $input = $tokenParser->tokenize($expression);
+
+        foreach ($input as $token) {
+            $this->categorizeToken($token);
+        }
+
+        while (!$this->stack->isEmpty()) {
+            $token = $this->stack->pop();
+
+            if ($token->getType() != Token::OPERATOR) {
+                throw new \Exception('Opening bracket without closing bracket');
+            }
+
+            $this->queue->push($token);
+        }
+
+        return $this->queue;
+    }
+
+    /**
+     * @param  Token      $token
+     * @throws \Exception
+     */
+    private function categorizeToken(Token $token)
+    {
+        switch ($token->getType()) {
+            case Token::NUMBER :
+                $this->queue->push($token);
+                break;
+
+            case Token::STRING:
+                if (array_key_exists($token->getValue(), $this->variables)) {
+                    $this->queue->push(new Token(Token::NUMBER, $this->variables[$token->getValue()]));
+                } else {
+                    $this->stack->push($token);
+                }
+                break;
+
+            case Token::LEFT_BRACKET:
+                $this->stack->push($token);
+                break;
+
+            case Token::RIGHT_BRACKET:
+                $previousToken = $this->stack->pop();
+                while (!$this->stack->isEmpty() && ($previousToken->getType() != Token::LEFT_BRACKET)) {
+                    $this->queue->push($previousToken);
+                    $previousToken = $this->stack->pop();
+                }
+                if ((!$this->stack->isEmpty()) && ($this->stack->top()->getType() == Token::STRING)) {
+                    $funcName = $this->stack->pop()->getValue();
+                    if (!array_key_exists($funcName, $this->functions)) {
+                        throw new UnknownFunctionException(sprintf(
+                            'Unknown function: "%s".',
+                            $funcName
+                        ));
+                    }
+                    $this->queue->push(new Token(Token::FUNC, $funcName));
+                }
+                break;
+
+            case Token::OPERATOR:
+                if (!array_key_exists($token->getValue(), $this->operators)) {
+                    throw new UnknownOperatorException(sprintf(
+                        'Unknown operator: "%s".',
+                        $token->getValue()
+                    ));
+                }
+
+                $this->proceedOperator($token);
+                $this->stack->push($token);
+                break;
+
+            default:
+                throw new UnknownTokenException(sprintf(
+                    'Unknown token: "%s".',
+                    $token->getValue()
+                ));
+        }
+    }
+
+    /**
+     * @param $token
+     * @throws \Exception
+     */
+    private function proceedOperator(Token $token)
+    {
+        if (!array_key_exists($token->getValue(), $this->operators)) {
+            throw new UnknownOperatorException(sprintf(
+                'Unknown operator: "%s".',
+                $token->getValue()
+            ));
+        }
+
+        /** @var Operand $operator */
+        $operator = $this->operators[$token->getValue()];
+
+        while (!$this->stack->isEmpty()) {
+            $top = $this->stack->top();
+
+            if ($top->getType() == Token::OPERATOR) {
+                /** @var Operand $operator */
+                $operator = $this->operators[$top->getValue()];
+                $priority = $operator->getPriority();
+                if ( $operator->getAssociation() == Operand::RIGHT_ASSOCIATED) {
+                    if (($priority > $operator->getPriority())) {
+                        $this->queue->push($this->stack->pop());
+                    } else {
+                        return;
+                    }
+                } else {
+                    if (($priority >= $operator->getPriority())) {
+                        $this->queue->push($this->stack->pop());
+                    } else {
+                        return;
+                    }
+                }
+            } elseif ($top->getType() == Token::STRING) {
+                $this->queue->push($this->stack->pop());
+            } else {
+                return;
+            }
+        }
+    }
+
+    /**
+     * @param  \SplQueue  $expression
+     * @return mixed
+     * @throws \Exception
+     */
+    private function calculateReversePolishNotation(\SplQueue $expression)
+    {
+        $this->stack = new \SplStack();
+        /** @var Token $token */
+        foreach ($expression as $token) {
+            switch ($token->getType()) {
+                case Token::NUMBER :
+                    $this->stack->push($token);
+                    break;
+
+                case Token::OPERATOR:
+                    /** @var Operand $operator */
+                    $operator = $this->operators[$token->getValue()];
+                    if ($operator->getType() == Operand::BINARY) {
+                        $arg2 = $this->stack->pop()->getValue();
+                        $arg1 = $this->stack->pop()->getValue();
+                    } else {
+                        $arg2 = null;
+                        $arg1 = $this->stack->pop()->getValue();
+                    }
+                    $callback = $operator->getCallback();
+
+                    $this->stack->push(new Token(Token::NUMBER, (call_user_func($callback, $arg1, $arg2))));
+                    break;
+
+                case Token::FUNC:
+                    /** @var Func $function */
+                    $callback = $this->functions[$token->getValue()];
+                    $arg = $this->stack->pop()->getValue();
+                    $this->stack->push(new Token(Token::NUMBER, (call_user_func($callback, $arg))));
+                    break;
+
+                default:
+                    throw new UnknownTokenException(sprintf(
+                        'Unknown token: "%s".',
+                        $token->getValue()
+                    ));
+            }
+        }
+
+        $result = $this->stack->pop()->getValue();
+
+        if (!$this->stack->isEmpty()) {
+            throw new IncorrectExpressionException('Incorrect expression.');
+        }
+
+        return $result;
+    }
+}