Subversion-Projekte lars-tiefland.laravel_shop

<?php

declare(strict_types=1);

namespace Doctrine\Common\Lexer;

use ReflectionClass;

use UnitEnum;

use function implode;

use function preg_split;

use function sprintf;

use function substr;

use const PREG_SPLIT_DELIM_CAPTURE;

use const PREG_SPLIT_NO_EMPTY;

use const PREG_SPLIT_OFFSET_CAPTURE;

/**

 * Base class for writing simple lexers, i.e. for creating small DSLs.

 *

 * @template T of UnitEnum|string|int

 * @template V of string|int

 */

abstract class AbstractLexer

{

    /**

     * Lexer original input string.

     */

    private string $input;

    /**

     * Array of scanned tokens.

     *

     * @var list<Token<T, V>>

     */

    private array $tokens = [];

    /**

     * Current lexer position in input string.

     */

    private int $position = 0;

    /**

     * Current peek of current lexer position.

     */

    private int $peek = 0;

    /**

     * The next token in the input.

     *

     * @var mixed[]|null

     * @psalm-var Token<T, V>|null

     */

    public Token|null $lookahead;

    /**

     * The last matched/seen token.

     *

     * @var mixed[]|null

     * @psalm-var Token<T, V>|null

     */

    public Token|null $token;

    /**

     * Composed regex for input parsing.

     */

    private string|null $regex = null;

    /**

     * Sets the input data to be tokenized.

     *

     * The Lexer is immediately reset and the new input tokenized.

     * Any unprocessed tokens from any previous input are lost.

     *

     * @param string $input The input to be tokenized.

     *

     * @return void

     */

    public function setInput(string $input)

    {

        $this->input  = $input;

        $this->tokens = [];

        $this->reset();

        $this->scan($input);

    }

    /**

     * Resets the lexer.

     *

     * @return void

     */

    public function reset()

    {

        $this->lookahead = null;

        $this->token     = null;

        $this->peek      = 0;

        $this->position  = 0;

    }

    /**

     * Resets the peek pointer to 0.

     *

     * @return void

     */

    public function resetPeek()

    {

        $this->peek = 0;

    }

    /**

     * Resets the lexer position on the input to the given position.

     *

     * @param int $position Position to place the lexical scanner.

     *

     * @return void

     */

    public function resetPosition(int $position = 0)

    {

        $this->position = $position;

    }

    /**

     * Retrieve the original lexer's input until a given position.

     *

     * @return string

     */

    public function getInputUntilPosition(int $position)

    {

        return substr($this->input, 0, $position);

    }

    /**

     * Checks whether a given token matches the current lookahead.

     *

     * @param T $type

     *

     * @return bool

     *

     * @psalm-assert-if-true !=null $this->lookahead

     */

    public function isNextToken(int|string|UnitEnum $type)

    {

        return $this->lookahead !== null && $this->lookahead->isA($type);

    }

    /**

     * Checks whether any of the given tokens matches the current lookahead.

     *

     * @param list<T> $types

     *

     * @return bool

     *

     * @psalm-assert-if-true !=null $this->lookahead

     */

    public function isNextTokenAny(array $types)

    {

        return $this->lookahead !== null && $this->lookahead->isA(...$types);

    }

    /**

     * Moves to the next token in the input string.

     *

     * @return bool

     *

     * @psalm-assert-if-true !null $this->lookahead

     */

    public function moveNext()

    {

        $this->peek      = 0;

        $this->token     = $this->lookahead;

        $this->lookahead = isset($this->tokens[$this->position])

            ? $this->tokens[$this->position++] : null;

        return $this->lookahead !== null;

    }

    /**

     * Tells the lexer to skip input tokens until it sees a token with the given value.

     *

     * @param T $type The token type to skip until.

     *

     * @return void

     */

    public function skipUntil(int|string|UnitEnum $type)

    {

        while ($this->lookahead !== null && ! $this->lookahead->isA($type)) {

            $this->moveNext();

        }

    }

    /**

     * Checks if given value is identical to the given token.

     *

     * @return bool

     */

    public function isA(string $value, int|string|UnitEnum $token)

    {

        return $this->getType($value) === $token;

    }

    /**

     * Moves the lookahead token forward.

     *

     * @return mixed[]|null The next token or NULL if there are no more tokens ahead.

     * @psalm-return Token<T, V>|null

     */

    public function peek()

    {

        if (isset($this->tokens[$this->position + $this->peek])) {

            return $this->tokens[$this->position + $this->peek++];

        }

        return null;

    }

    /**

     * Peeks at the next token, returns it and immediately resets the peek.

     *

     * @return mixed[]|null The next token or NULL if there are no more tokens ahead.

     * @psalm-return Token<T, V>|null

     */

    public function glimpse()

    {

        $peek       = $this->peek();

        $this->peek = 0;

        return $peek;

    }

    /**

     * Scans the input string for tokens.

     *

     * @param string $input A query string.

     *

     * @return void

     */

    protected function scan(string $input)

    {

        if (! isset($this->regex)) {

            $this->regex = sprintf(

                '/(%s)|%s/%s',

                implode(')|(', $this->getCatchablePatterns()),

                implode('|', $this->getNonCatchablePatterns()),

                $this->getModifiers(),

            );

        }

        $flags   = PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_OFFSET_CAPTURE;

        $matches = preg_split($this->regex, $input, -1, $flags);

        if ($matches === false) {

            // Work around https://bugs.php.net/78122

            $matches = [[$input, 0]];

        }

        foreach ($matches as $match) {

            // Must remain before 'value' assignment since it can change content

            $firstMatch = $match[0];

            $type       = $this->getType($firstMatch);

            $this->tokens[] = new Token(

                $firstMatch,

                $type,

                $match[1],

            );

        }

    }

    /**

     * Gets the literal for a given token.

     *

     * @param T $token

     *

     * @return int|string

     */

    public function getLiteral(int|string|UnitEnum $token)

    {

        if ($token instanceof UnitEnum) {

            return $token::class . '::' . $token->name;

        }

        $className = static::class;

        $reflClass = new ReflectionClass($className);

        $constants = $reflClass->getConstants();

        foreach ($constants as $name => $value) {

            if ($value === $token) {

                return $className . '::' . $name;

            }

        }

        return $token;

    }

    /**

     * Regex modifiers

     *

     * @return string

     */

    protected function getModifiers()

    {

        return 'iu';

    }

    /**

     * Lexical catchable patterns.

     *

     * @return string[]

     */

    abstract protected function getCatchablePatterns();

    /**

     * Lexical non-catchable patterns.

     *

     * @return string[]

     */

    abstract protected function getNonCatchablePatterns();

    /**

     * Retrieve token type. Also processes the token value if necessary.

     *

     * @return T|null

     *

     * @param-out V $value

     */

    abstract protected function getType(string &$value);

}