<?php

/**

* Class parser

* Parser for simple PHP arrays

* Modified by battye, originally from: http://jsteemann.github.io/blog/2015/06/16/parsing-php-arrays-with-php/

*/

namespace battye\array_parser;

use battye\array_parser\exception\parser_exception;

class parser

{

const NOT_STRING_LITERAL = '-- Not a supported string literal (unprocessed value). --';

private static $CONSTANTS = array(

'null' => null,

'true' => true,

'false' => false

);

private $tokens;

/**

* parser constructor.

* @param tokens $tokens

*/

public function __construct(tokens $tokens)

{

$this->tokens = $tokens;

}

/**

* Simple parser to convert a simple string to an array

* @param $value

* @return array

* @throws parser_exception

*/

public static function parse_simple($value)

{

$tokens = new tokens($value);

$parser = new parser($tokens);

$result = $parser->parse_array($tokens->does_match('['));

return $result;

}

/**

* Simple and generic regex parser, made with phpBB in mind.

* @param $regex

* @param $path

* @param int $group capture group

* @return array|null

* @throws parser_exception

*/

public static function parse_regex($regex, $path, $group = 1)

{

if (!file_exists($path))

{

// The file does not exist, so exit cleanly

throw new parser_exception('The specified file does not exist: ' . $path);

}

// Find a regex match

$result = null;

$file = file_get_contents($path);

preg_match_all($regex, $file, $matches);

$multiple_matches = count($matches[$group]);

$parse = function($match) {

$tokens = new tokens($match, true);

$parser = new parser($tokens);

$result = $parser->parse_array();

if (!$tokens->done())

{

throw new parser_exception('Still tokens left after parsing.');

}

return $result;

};

// Return the results in an array

$result = [];

if ($multiple_matches > 0)

{

foreach ($matches[$group] as $match)

{

$result[] = $parse($match);

}

}

return $result;

}

/**

* Parse each token

* @return float|int|string

* @throws parser_exception

*/

public function parse_value()

{

// Ignore values that rely on another variable

if (!$this->tokens->done())

{

if (is_array($this->tokens->peek()) && count($this->tokens->peek()) > 1 && substr($this->tokens->peek()[1], 0, 1) === "$")

{

// If a variable is being used as a value then don't bother with this any more

$literalValue = self::NOT_STRING_LITERAL;

while (!$this->tokens->does_match(","))

{

if ($this->tokens->does_match(")"))

{

return $literalValue;

}

$this->tokens->pop(); // Ignore comments

}

return $literalValue;

}

}

if ($this->tokens->does_match(T_CONSTANT_ENCAPSED_STRING))

{

// Strings

$token = $this->tokens->pop();

return stripslashes(substr($token[1], 1, -1));

}

if ($this->tokens->does_match(T_STRING))

{

// Built-in string literals: null, false, true

$token = $this->tokens->pop();

$value = strtolower($token[1]);

if (array_key_exists($value, self::$CONSTANTS))

{

return self::$CONSTANTS[$value];

}

throw new parser_exception('Unexpected string literal: ' . $token[1]);

}

else if ($this->tokens->does_match(T_ARRAY) || $this->tokens->does_match('['))

{

$square_bracket_array = $this->tokens->does_match('[');

return $this->parse_array($square_bracket_array);

}

// The rest...

// We expect a number here

$uminus = 1;

if ($this->tokens->does_match("-"))

{

// Unary minus

$this->tokens->force_match("-");

$uminus = -1;

}

if ($this->tokens->does_match(T_LNUMBER))

{

// Long number

$value = $this->tokens->pop();

return $uminus * (int) $value[1];

}

if ($this->tokens->does_match(T_DNUMBER))

{

// Double number

$value = $this->tokens->pop();

return $uminus * (double) $value[1];

}

throw new parser_exception('Unexpected token encountered, potentially due to a malformed array.');

}

/**

* Disregard comments when parsing

* @throws parser_exception

*/

public function ignore_comments()

{

if (!$this->tokens->done())

{

// Check for both short and long form comment blocks

while (is_array($this->tokens->peek()) && count($this->tokens->peek()) > 1 && $this->is_comment_block($this->tokens->peek()[1]))

{

$this->tokens->pop(); // Ignore comments

}

}

}

/**

* Determine whether something is a comment

* @param $code

* @return bool

*/

public function is_comment_block($code)

{

// Short form

$short = (substr($code, 0, 2) === "//");

// Long form block

$long = (substr($code, 0, 2) == '/*' && substr($code, -2) == '*/');

// Hash form

$hash = (substr($code, 0, 1) === '#');

return ($short || $long || $hash);

}

/**

* @param bool $square

* @return array

* @throws parser_exception

*/

public function parse_array($square = false)

{

$found = 0;

$result = array();

if ($square)

{

$this->tokens->force_match("[");

}

else

{

$this->tokens->force_match(T_ARRAY);

$this->tokens->force_match("(");

}

while (true)

{

// Immediately ignore any comments

$this->ignore_comments();

if ($this->tokens->does_match(")") || $this->tokens->does_match("]"))

{

// Reached the end of the array

if ($square)

{

$this->tokens->force_match("]");

}

else

{

$this->tokens->force_match(")");

}

// If we are done, just break immediately

if ($this->tokens->done())

{

break;

}

if ($this->tokens->does_match(";"))

{

$this->tokens->force_match(";");

}

break;

}

if ($found > 0)

{

// We must see a comma following the first element

$this->tokens->force_match(",");

$this->ignore_comments();

if ($square && $this->tokens->does_match("]"))

{

// end of the square bracket array

$this->tokens->force_match("]");

break;

}

if ($this->tokens->does_match(")"))

{

// reached the end of the array

$this->tokens->force_match(")");

break;

}

}

$this->ignore_comments();

if ($this->tokens->does_match(T_ARRAY) || $this->tokens->does_match('['))

{

$square_bracket_array = $this->tokens->does_match('[');

// Nested array

$result[] = $this->parse_array($square_bracket_array);

}

else if ($this->tokens->does_match(T_CONSTANT_ENCAPSED_STRING) || $this->tokens->does_match(T_LNUMBER))

{

// String

$string = $this->parse_value();

if ($this->tokens->does_match(T_DOUBLE_ARROW))

{

// Array key (key => value)

$this->tokens->pop();

// Ignore comments in case someone put them on a new line within the array

$this->ignore_comments();

$result[$string] = $this->parse_value();

}

else

{

// simple string

$result[] = $string;

}

}

else

{

$result[] = $this->parse_value();

}

++$found;

}

return $result;

}

}