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Diffstat (limited to 'src/NXP/Classes/Tokenizer.php')
| -rw-r--r-- | src/NXP/Classes/Tokenizer.php | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/src/NXP/Classes/Tokenizer.php b/src/NXP/Classes/Tokenizer.php new file mode 100644 index 0000000..b72b869 --- /dev/null +++ b/src/NXP/Classes/Tokenizer.php @@ -0,0 +1,302 @@ +<?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\Exception\IncorrectBracketsException; +use NXP\Exception\UnknownOperatorException; +use RuntimeException; +use SplStack; + +/** + * @author Alexander Kiryukhin <a.kiryukhin@mail.ru> + */ +class Tokenizer +{ + /** + * @var Token[] + */ + public $tokens = []; + /** + * @var string + */ + private $input = ""; + /** + * @var string + */ + private $numberBuffer = ""; + /** + * @var string + */ + private $stringBuffer = ""; + /** + * @var bool + */ + private $allowNegative = true; + /** + * @var Operator[] + */ + private $operators = []; + + /** + * @var bool + */ + private $inSingleQuotedString = false; + + /** + * @var bool + */ + private $inDoubleQuotedString = false; + + /** + * Tokenizer constructor. + * @param string $input + * @param Operator[] $operators + */ + public function __construct(string $input, array $operators) + { + $this->input = $input; + $this->operators = $operators; + } + + public function tokenize() + { + foreach (str_split($this->input, 1) as $ch) { + switch (true) { + case $this->inSingleQuotedString: + if ($ch === "'") { + $this->tokens[] = new Token(Token::String, $this->stringBuffer); + $this->inSingleQuotedString = false; + $this->stringBuffer = ""; + continue 2; + } + $this->stringBuffer .= $ch; + continue 2; + case $this->inDoubleQuotedString: + if ($ch === "\"") { + $this->tokens[] = new Token(Token::String, $this->stringBuffer); + $this->inDoubleQuotedString = false; + $this->stringBuffer = ""; + continue 2; + } + $this->stringBuffer .= $ch; + continue 2; + case $ch == " " || $ch == "\n" || $ch == "\r" || $ch == "\t": + $this->tokens[] = new Token(Token::Space, ""); + continue 2; + case $this->isNumber($ch): + if ($this->stringBuffer != "") { + $this->stringBuffer .= $ch; + continue 2; + } + $this->numberBuffer .= $ch; + $this->allowNegative = false; + break; + /** @noinspection PhpMissingBreakStatementInspection */ + case strtolower($ch) === "e": + if ($this->numberBuffer != "" && strpos($this->numberBuffer, ".") !== false) { + $this->numberBuffer .= "e"; + $this->allowNegative = true; + break; + } + case $this->isAlpha($ch): + if ($this->numberBuffer != "") { + $this->emptyNumberBufferAsLiteral(); + $this->tokens[] = new Token(Token::Operator, "*"); + } + $this->allowNegative = false; + $this->stringBuffer .= $ch; + break; + case $ch == "\"": + $this->inDoubleQuotedString = true; + continue 2; + case $ch == "'": + $this->inSingleQuotedString = true; + continue 2; + + case $this->isDot($ch): + $this->numberBuffer .= $ch; + $this->allowNegative = false; + break; + case $this->isLP($ch): + if ($this->stringBuffer != "") { + $this->tokens[] = new Token(Token::Function, $this->stringBuffer); + $this->stringBuffer = ""; + } elseif ($this->numberBuffer != "") { + $this->emptyNumberBufferAsLiteral(); + $this->tokens[] = new Token(Token::Operator, "*"); + } + $this->allowNegative = true; + $this->tokens[] = new Token(Token::LeftParenthesis, ""); + break; + case $this->isRP($ch): + $this->emptyNumberBufferAsLiteral(); + $this->emptyStrBufferAsVariable(); + $this->allowNegative = false; + $this->tokens[] = new Token(Token::RightParenthesis, ""); + break; + case $this->isComma($ch): + $this->emptyNumberBufferAsLiteral(); + $this->emptyStrBufferAsVariable(); + $this->allowNegative = true; + $this->tokens[] = new Token(Token::ParamSeparator, ""); + break; + default: + if ($this->allowNegative && $ch == "-") { + $this->allowNegative = false; + $this->numberBuffer .= "-"; + continue 2; + } + $this->emptyNumberBufferAsLiteral(); + $this->emptyStrBufferAsVariable(); + if (count($this->tokens) > 0) { + if ($this->tokens[count($this->tokens) - 1]->type === Token::Operator) { + $this->tokens[count($this->tokens) - 1]->value .= $ch; + } else { + $this->tokens[] = new Token(Token::Operator, $ch); + } + } else { + $this->tokens[] = new Token(Token::Operator, $ch); + } + $this->allowNegative = true; + } + } + $this->emptyNumberBufferAsLiteral(); + $this->emptyStrBufferAsVariable(); + return $this; + } + + private function isNumber($ch) + { + return $ch >= '0' && $ch <= '9'; + } + + private function isAlpha($ch) + { + return $ch >= 'a' && $ch <= 'z' || $ch >= 'A' && $ch <= 'Z' || $ch == '_'; + } + + private function emptyNumberBufferAsLiteral() + { + if ($this->numberBuffer != "") { + $this->tokens[] = new Token(Token::Literal, $this->numberBuffer); + $this->numberBuffer = ""; + } + } + + private function isDot($ch) + { + return $ch == '.'; + } + + private function isLP($ch) + { + return $ch == '('; + } + + private function isRP($ch) + { + return $ch == ')'; + } + + private function emptyStrBufferAsVariable() + { + if ($this->stringBuffer != "") { + $this->tokens[] = new Token(Token::Variable, $this->stringBuffer); + $this->stringBuffer = ""; + } + } + + private function isComma($ch) + { + return $ch == ','; + } + + /** + * @return Token[] Array of tokens in revers polish notation + * @throws IncorrectBracketsException + * @throws UnknownOperatorException + */ + public function buildReversePolishNotation() + { + $tokens = []; + /** @var SplStack<Token> $stack */ + $stack = new SplStack(); + foreach ($this->tokens as $token) { + switch ($token->type) { + case Token::Literal: + case Token::Variable: + case Token::String: + $tokens[] = $token; + break; + case Token::Function: + case Token::LeftParenthesis: + $stack->push($token); + break; + case Token::ParamSeparator: + while ($stack->top()->type !== Token::LeftParenthesis) { + if ($stack->count() === 0) { + throw new IncorrectBracketsException(); + } + $tokens[] = $stack->pop(); + } + break; + case Token::Operator: + if (!array_key_exists($token->value, $this->operators)) { + throw new UnknownOperatorException(); + } + $op1 = $this->operators[$token->value]; + while ($stack->count() > 0 && $stack->top()->type === Token::Operator) { + if (!array_key_exists($stack->top()->value, $this->operators)) { + throw new UnknownOperatorException(); + } + $op2 = $this->operators[$stack->top()->value]; + if ($op2->priority >= $op1->priority) { + $tokens[] = $stack->pop(); + continue; + } + break; + } + $stack->push($token); + break; + case Token::RightParenthesis: + while (true) { + try { + $ctoken = $stack->pop(); + if ($ctoken->type === Token::LeftParenthesis) { + break; + } + $tokens[] = $ctoken; + } catch (RuntimeException $e) { + throw new IncorrectBracketsException(); + } + } + if ($stack->count() > 0 && $stack->top()->type == Token::Function) { + $tokens[] = $stack->pop(); + } + break; + case Token::Space: + //do nothing + } + } + while ($stack->count() !== 0) { + if ($stack->top()->type === Token::LeftParenthesis || $stack->top()->type === Token::RightParenthesis) { + throw new IncorrectBracketsException(); + } + if ($stack->top()->type === Token::Space) { + $stack->pop(); + continue; + } + $tokens[] = $stack->pop(); + } + return $tokens; + } +} + |