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<?php
/**
* Defines a token along with a set of types and flags and utility functions.
*
* An array of tokens will result after parsing the query.
*
* @package SqlParser
*/
namespace SqlParser;
/**
* A structure representing a lexeme that explicitly indicates its
* categorization for the purpose of parsing.
*
* @category Tokens
* @package SqlParser
* @author Dan Ungureanu <udan1107@gmail.com>
* @license http://opensource.org/licenses/GPL-2.0 GNU Public License
*/
class Token
{
// Types of tokens (a vague description of a token's purpose).
/**
* This type is used when the token is invalid or its type cannot be
* determined because of the ambiguous context. Further analysis might be
* required to detect its type.
*
* @var int
*/
const TYPE_NONE = 0;
/**
* SQL specific keywords: SELECT, UPDATE, INSERT, etc.
*
* @var int
*/
const TYPE_KEYWORD = 1;
/**
* Any type of legal operator.
*
* Arithmetic operators: +, -, *, /, etc.
* Logical operators: ===, <>, !==, etc.
* Bitwise operators: &, |, ^, etc.
* Assignment operators: =, +=, -=, etc.
* SQL specific operators: . (e.g. .. WHERE database.table ..),
* * (e.g. SELECT * FROM ..)
*
* @var int
*/
const TYPE_OPERATOR = 2;
/**
* Spaces, tabs, new lines, etc.
*
* @var int
*/
const TYPE_WHITESPACE = 3;
/**
* Any type of legal comment.
*
* Bash (#), C (/* *\/) or SQL (--) comments:
*
* -- SQL-comment
*
* #Bash-like comment
*
* /*C-like comment*\/
*
* or:
*
* /*C-like
* comment*\/
*
* Backslashes were added to respect PHP's comments syntax.
*
* @var int
*/
const TYPE_COMMENT = 4;
/**
* Boolean values: true or false.
*
* @var int
*/
const TYPE_BOOL = 5;
/**
* Numbers: 4, 0x8, 15.16, 23e42, etc.
*
* @var int
*/
const TYPE_NUMBER = 6;
/**
* Literal strings: 'string', "test".
* Some of these strings are actually symbols.
*
* @var int
*/
const TYPE_STRING = 7;
/**
* Database, table names, variables, etc.
* For example: ```SELECT `foo`, `bar` FROM `database`.`table`;```
*
* @var int
*/
const TYPE_SYMBOL = 8;
/**
* Delimits an unknown string.
* For example: ```SELECT * FROM test;```, `test` is a delimiter.
*
* @var int
*/
const TYPE_DELIMITER = 9;
// Flags that describe the tokens in more detail.
// All keywords must have flag 1 so `Context::isKeyword` method doesn't
// require strict comparison.
const FLAG_KEYWORD_RESERVED = 2;
const FLAG_KEYWORD_COMPOSED = 4;
const FLAG_KEYWORD_DATA_TYPE = 8;
const FLAG_KEYWORD_KEY = 16;
const FLAG_KEYWORD_FUNCTION = 32;
// Numbers related flags.
const FLAG_NUMBER_HEX = 1;
const FLAG_NUMBER_FLOAT = 2;
const FLAG_NUMBER_APPROXIMATE = 4;
const FLAG_NUMBER_NEGATIVE = 8;
const FLAG_NUMBER_BINARY = 16;
// Strings related flags.
const FLAG_STRING_SINGLE_QUOTES = 1;
const FLAG_STRING_DOUBLE_QUOTES = 2;
// Comments related flags.
const FLAG_COMMENT_BASH = 1;
const FLAG_COMMENT_C = 2;
const FLAG_COMMENT_SQL = 4;
const FLAG_COMMENT_MYSQL_CMD = 8;
// Operators related flags.
const FLAG_OPERATOR_ARITHMETIC = 1;
const FLAG_OPERATOR_LOGICAL = 2;
const FLAG_OPERATOR_BITWISE = 4;
const FLAG_OPERATOR_ASSIGNMENT = 8;
const FLAG_OPERATOR_SQL = 16;
// Symbols related flags.
const FLAG_SYMBOL_VARIABLE = 1;
const FLAG_SYMBOL_BACKTICK = 2;
const FLAG_SYMBOL_USER = 4;
const FLAG_SYMBOL_SYSTEM = 8;
/**
* The token it its raw string representation.
*
* @var string
*/
public $token;
/**
* The value this token contains (i.e. token after some evaluation)
*
* @var mixed
*/
public $value;
/**
* The type of this token.
*
* @var int
*/
public $type;
/**
* The flags of this token.
*
* @var int
*/
public $flags;
/**
* The position in the initial string where this token started.
*
* @var int
*/
public $position;
/**
* Constructor.
*
* @param string $token The value of the token.
* @param int $type The type of the token.
* @param int $flags The flags of the token.
*/
public function __construct($token, $type = 0, $flags = 0)
{
$this->token = $token;
$this->type = $type;
$this->flags = $flags;
$this->value = $this->extract();
}
/**
* Does little processing to the token to extract a value.
*
* If no processing can be done it will return the initial string.
*
* @return mixed
*/
public function extract()
{
switch ($this->type) {
case Token::TYPE_KEYWORD:
if (!($this->flags & Token::FLAG_KEYWORD_RESERVED)) {
// Unreserved keywords should stay the way they are because they
// might represent field names.
return $this->token;
}
return strtoupper($this->token);
case Token::TYPE_WHITESPACE:
return ' ';
case Token::TYPE_BOOL:
return strtoupper($this->token) === 'TRUE';
case Token::TYPE_NUMBER:
$ret = str_replace('--', '', $this->token); // e.g. ---42 === -42
if ($this->flags & Token::FLAG_NUMBER_HEX) {
if ($this->flags & Token::FLAG_NUMBER_NEGATIVE) {
$ret = str_replace('-', '', $this->token);
sscanf($ret, "%x", $ret);
$ret = -$ret;
} else {
sscanf($ret, "%x", $ret);
}
} elseif (($this->flags & Token::FLAG_NUMBER_APPROXIMATE)
|| ($this->flags & Token::FLAG_NUMBER_FLOAT)
) {
sscanf($ret, "%f", $ret);
} else {
sscanf($ret, "%d", $ret);
}
return $ret;
case Token::TYPE_STRING:
$quote = $this->token[0];
$str = str_replace($quote . $quote, $quote, $this->token);
return mb_substr($str, 1, -1, 'UTF-8'); // trims quotes
case Token::TYPE_SYMBOL:
$str = $this->token;
if ((isset($str[0])) && ($str[0] === '@')) {
// `mb_strlen($str)` must be used instead of `null` because
// in PHP 5.3- the `null` parameter isn't handled correctly.
$str = mb_substr(
$str,
((!empty($str[1])) && ($str[1] === '@')) ? 2 : 1,
mb_strlen($str),
'UTF-8'
);
}
if ((isset($str[0])) && (($str[0] === '`')
|| ($str[0] === '"') || ($str[0] === '\''))
) {
$quote = $str[0];
$str = str_replace($quote . $quote, $quote, $str);
$str = mb_substr($str, 1, -1, 'UTF-8');
}
return $str;
}
return $this->token;
}
/**
* Converts the token into an inline token by replacing tabs and new lines.
*
* @return string
*/
public function getInlineToken()
{
return str_replace(
array("\r", "\n", "\t"),
array('\r', '\n', '\t'),
$this->token
);
}
}
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