cfnpp/app/Cfnpp/Expression/TokenStringLiteral.php

<?php

declare(strict_types=1);

namespace App\Cfnpp\Expression;

/**
 * Token representing a string literal.
 *
 * @author Adam Pippin <hello@adampippin.ca>
 */
class TokenStringLiteral extends Token
{
	/**
	 * Value of the string literal.
	 * @var string
	 */
	protected $value;

	/**
	 * Create a new string literal token.
	 *
	 * @param string $value
	 */
	public function __construct(string $value)
	{
		$this->value = $value;
	}

	/**
	 * Get the value of the string literal.
	 *
	 * @return string
	 */
	public function getValue(): string
	{
		return $this->value;
	}

	/**
	 * Determine whether a string token can be parsed from a stream.
	 *
	 * @param  string $stream
	 * @return bool
	 */
	public static function isToken(string $stream): bool
	{
		return $stream[0] == '"';
	}

	/**
	 * Parse a string literal token from a stream.
	 *
	 * Returns token, and modifies stream to remove all consumed characters
	 *
	 * @param  string $stream
	 * @return Token
	 */
	public static function getToken(string &$stream): Token
	{
		$buffer = '';
		$in_string = false;
		$escaped = false;

		for ($i = 0; $i < strlen($stream); $i++)
		{
			if ($escaped)
			{
				$buffer .= $stream[$i];
				$escaped = false;
			}
			elseif ($stream[$i] == '"')
			{
				if ($in_string)
				{
					break;
				}

				$in_string = true;
			}
			elseif ($stream[$i] == '\\')
			{
				$escaped = true;
			}
			else
			{
				$buffer .= $stream[$i];
			}
		}

		$stream = substr($stream, $i + 1);

		return new TokenStringLiteral($buffer);
	}
}