"word*word" => REGEX(word.*word)
*
*
* The full query syntax, in order of precedence, is roughly:
*
* The unary 'NOT' or '-' operator (they are equivalent) negates the
* following search clause.
*
* Search clauses may be joined with the (left-associative) binary operators
* 'AND' and 'OR'. (case-insensitive)
*
* Two adjoining search clauses are joined with an implicit 'AND'. This has
* lower precedence than either an explicit 'AND' or 'OR', so "a b OR c"
* parses as "a AND ( b OR c )", while "a AND b OR c" parses as
* "( a AND b ) OR c" (due to the left-associativity of 'AND' and 'OR'.)
*
* Search clauses can be grouped with parentheses.
*
* Phrases (or other things which don't look like words) can be forced to
* be interpreted as words by quoting them, either with single (') or double (")
* quotes. If you wan't to include the quote character within a quoted string,
* double-up on the quote character: 'I''m hungry' is equivalent to
* "I'm hungry".
*
* Force regex on "re:word" => posix-style, "/word/" => pcre-style
* or use regex='glob' to use file wildcard-like matching. (not yet)
*
* The parsed tree is then converted to the needed PCRE (highlight,
* simple backends) or SQL functions.
*
* @author: Jeff Dairiki
* @author: Reini Urban (case and regex detection, enhanced sql callbacks)
*/
// regex-style: 'auto', 'none', 'glob', 'posix', 'pcre', 'sql'
define ('TSQ_REGEX_NONE', 0);
define ('TSQ_REGEX_AUTO', 1);
define ('TSQ_REGEX_POSIX', 2);
define ('TSQ_REGEX_GLOB', 4);
define ('TSQ_REGEX_PCRE', 8);
define ('TSQ_REGEX_SQL', 16);
define ('TSQ_TOK_VOID', 0);
define ('TSQ_TOK_BINOP', 1);
define ('TSQ_TOK_NOT', 2);
define ('TSQ_TOK_LPAREN', 4);
define ('TSQ_TOK_RPAREN', 8);
define ('TSQ_TOK_WORD', 16);
define ('TSQ_TOK_STARTS_WITH', 32);
define ('TSQ_TOK_ENDS_WITH', 64);
define ('TSQ_TOK_EXACT', 128);
define ('TSQ_TOK_REGEX', 256);
define ('TSQ_TOK_REGEX_GLOB', 512);
define ('TSQ_TOK_REGEX_PCRE', 1024);
define ('TSQ_TOK_REGEX_SQL', 2048);
define ('TSQ_TOK_ALL', 4096);
// all bits from word to the last.
define ('TSQ_ALLWORDS', (4096 * 2) - 1 - (16 - 1));
/*
define ('TSQ_NODE_ALL', 0);
define ('TSQ_NODE_EXACT', 1);
define ('TSQ_NODE_NOT', 2);
define ('TSQ_NODE_WORD', 3);
define ('TSQ_NODE_STARTS_WITH', 4);
define ('TSQ_NODE_ENDS_WITH', 5);
define ('TSQ_NODE_REGEX', 6);
define ('TSQ_NODE_REGEX_GLOB', 7);
define ('TSQ_NODE_REGEX_PCRE', 8);
define ('TSQ_NODE_REGEX_SQL', 9);
define ('TSQ_NODE_AND', 10);
define ('TSQ_NODE_OR', 11);
*/
class TextSearchQuery
{
/**
* Create a new query.
*
* @param $search_query string The query. Syntax is as described above.
* Note that an empty $search_query will match anything.
* @param $case_exact boolean
* @param $regex string one of 'auto', 'none', 'glob', 'posix', 'pcre', 'sql'
* @see TextSearchQuery
*/
function TextSearchQuery($search_query, $case_exact = false, $regex = 'auto')
{
if ($regex == 'none' or !$regex)
$this->_regex = 0;
elseif (defined("TSQ_REGEX_" . strtoupper($regex)))
$this->_regex = constant("TSQ_REGEX_" . strtoupper($regex)); else {
trigger_error(fmt("Unsupported argument: %s=%s", 'regex', $regex));
$this->_regex = 0;
}
$this->_regex_modifier = ($case_exact ? '' : 'i') . 'sS';
$this->_case_exact = $case_exact;
if ($regex != 'pcre') {
$parser = new TextSearchQuery_Parser;
$this->_tree = $parser->parse($search_query, $case_exact, $this->_regex);
$this->_optimize(); // broken under certain circumstances: "word -word -word"
if (defined("FULLTEXTSEARCH_STOPLIST"))
$this->_stoplist = FULLTEXTSEARCH_STOPLIST;
else // default stoplist, localizable.
$this->_stoplist = _("(A|An|And|But|By|For|From|In|Is|It|Of|On|Or|The|To|With)");
} else {
$this->_tree = new TextSearchQuery_node_regex_pcre($search_query);
if (preg_match("/^\/(.*)\/(\w*)$/", $search_query, $m)) {
$this->_tree->word = $m[1];
$this->_regex_modifier = $m[2]; // overrides case_exact
}
}
}
function getType()
{
return 'text';
}
function _optimize()
{
$this->_tree = $this->_tree->optimize();
}
/**
* Get a PCRE regexp which matches the query.
*/
function asRegexp()
{
if (!isset($this->_regexp)) {
if (!isset($this->_regex_modifier))
$this->_regex_modifier = ($this->_case_exact ? '' : 'i') . 'sS';
if ($this->_regex)
$this->_regexp = '/' . $this->_tree->regexp() . '/' . $this->_regex_modifier;
else
$this->_regexp = '/^' . $this->_tree->regexp() . '/' . $this->_regex_modifier;
}
return $this->_regexp;
}
/**
* Match query against string.
* EXACT ("Term") ignores the case_exact setting.
*
* @param $string string The string to match.
* @return boolean True if the string matches the query.
*/
function match($string)
{
if ($this->_tree->_op == TSQ_TOK_ALL) return true;
if ($this->_tree->_op == TSQ_TOK_EXACT) return $this->_tree->word == $string;
return preg_match($this->asRegexp(), $string);
}
/* How good does it match? Returns a number */
function score($string)
{
$score = 0.0;
$i = 10;
foreach (array_unique($this->_tree->highlight_words()) as $word) {
if ($nummatch = preg_match_all("/" . preg_quote($word, '/') . "/" .
$this->_regex_modifier,
$string, $out)
)
$score += ($i-- * $nummatch);
}
return min(1.0, $score / 10.0);
}
/**
* Get a regular expression suitable for highlighting matched words.
*
* This returns a PCRE regular expression which matches any non-negated
* word in the query.
*
* @return string The PCRE regexp.
*/
function getHighlightRegexp()
{
if (!isset($this->_hilight_regexp)) {
$words = array_unique($this->_tree->highlight_words());
if (!$words) {
$this->_hilight_regexp = false;
} else {
foreach ($words as $key => $word)
$words[$key] = preg_quote($word, '/');
$this->_hilight_regexp = '(?' . ($this->_case_exact ? '' : 'i') . ':'
. join('|', $words) . ')';
}
}
return $this->_hilight_regexp;
}
/**
* Make an SQL clause which matches the query.
* Deprecated, use makeSqlClauseObj instead.
*
* @param $make_sql_clause_cb WikiCallback
* A callback which takes a single word as an argument and
* returns an SQL clause which will match exactly those records
* containing the word. The word passed to the callback will always
* be in all lower case.
*
* Support db-specific extensions, like MATCH AGAINST or REGEX
* mysql => 4.0.1 can also do Google: MATCH AGAINST IN BOOLEAN MODE
* by using makeSqlClauseObj
*
* Old example usage:
*
* function sql_title_match($word) {
* return sprintf("LOWER(title) like '%s'",
* addslashes($word));
* }
*
* ...
*
* $query = new TextSearchQuery("wiki -page");
* $cb = new WikiFunctionCb('sql_title_match');
* $sql_clause = $query->makeSqlClause($cb);
*
* This will result in $sql_clause containing something like
* "(LOWER(title) like 'wiki') AND NOT (LOWER(title) like 'page')".
*
* @return string The SQL clause.
*/
function makeSqlClause($sql_clause_cb)
{
$this->_sql_clause_cb = $sql_clause_cb;
return $this->_sql_clause($this->_tree);
}
// deprecated: use _sql_clause_obj now.
function _sql_clause($node)
{
switch ($node->_op) {
case TSQ_TOK_WORD: // word => %word%
return $this->_sql_clause_cb->call($node->word);
case TSQ_TOK_NOT:
return "NOT (" . $this->_sql_clause($node->leaves[0]) . ")";
case TSQ_TOK_BINOP:
$subclauses = array();
foreach ($node->leaves as $leaf)
$subclauses[] = "(" . $this->_sql_clause($leaf) . ")";
return join(" $node->op ", $subclauses);
default:
assert($node->_op == TSQ_TOK_VOID);
return '1=1';
}
}
/** Get away with the callback and use a db-specific search class instead.
* @see WikiDB_backend_PearDB_search
*/
function makeSqlClauseObj(&$sql_search_cb)
{
$this->_sql_clause_cb = $sql_search_cb;
return $this->_sql_clause_obj($this->_tree);
}
function _sql_clause_obj($node)
{
switch ($node->_op) {
case TSQ_TOK_NOT:
return "NOT (" . $this->_sql_clause_cb->call($node->leaves[0]) . ")";
case TSQ_TOK_BINOP:
$subclauses = array();
foreach ($node->leaves as $leaf)
$subclauses[] = "(" . $this->_sql_clause_obj($leaf) . ")";
return join(" $node->op ", $subclauses);
case TSQ_TOK_VOID:
return '0=1';
case TSQ_TOK_ALL:
return '1=1';
default:
return $this->_sql_clause_cb->call($node);
}
}
/*
postgresql tsearch2 uses no WHERE operators, just & | and ! in the searchstring
*/
function makeTsearch2SqlClauseObj(&$sql_search_cb)
{
$this->_sql_clause_cb = $sql_search_cb;
return $this->_Tsearch2Sql_clause_obj($this->_tree);
}
function _Tsearch2Sql_clause_obj($node)
{
// TODO: "such a phrase"
switch ($node->_op) {
case TSQ_TOK_NOT:
return "!" . $node->leaves[0];
case TSQ_TOK_BINOP:
$subclauses = array();
foreach ($node->leaves as $leaf)
$subclauses[] = $this->_Tsearch2Sql_clause_obj($leaf);
return join($node->_op == 'AND' ? "&" : "|", $subclauses);
case TSQ_TOK_VOID:
return '';
case TSQ_TOK_ALL:
return '1';
default:
return $this->_sql_clause_cb->call($node);
}
}
function sql()
{
return '%' . $this->_sql_quote($this->word) . '%';
}
/**
* Get printable representation of the parse tree.
*
* This is for debugging only.
* @return string Printable parse tree.
*/
function asString()
{
return $this->_as_string($this->_tree);
}
function _as_string($node, $indent = '')
{
switch ($node->_op) {
case TSQ_TOK_WORD:
return $indent . "WORD: $node->word";
case TSQ_TOK_VOID:
return $indent . "VOID";
case TSQ_TOK_ALL:
return $indent . "ALL";
default:
$lines = array($indent . $node->op . ":");
$indent .= " ";
foreach ($node->leaves as $leaf)
$lines[] = $this->_as_string($leaf, $indent);
return join("\n", $lines);
}
}
}
/**
* This is a TextSearchQuery which matches nothing.
*/
class NullTextSearchQuery extends TextSearchQuery
{
/**
* Create a new query.
*
* @see TextSearchQuery
*/
function NullTextSearchQuery()
{
}
function asRegexp()
{
return '/^(?!a)a/x';
}
function match($string)
{
return false;
}
function getHighlightRegexp()
{
return "";
}
function makeSqlClause($make_sql_clause_cb)
{
return "(1 = 0)";
}
function asString()
{
return "NullTextSearchQuery";
}
}
/**
* A simple algebraic matcher for numeric attributes.
* NumericSearchQuery can do ("population < 20000 and area > 1000000", array("population", "area"))
* ->match(array('population' => 100000, 'area' => 10000000))
*
* Supports all mathematical PHP comparison operators, plus ':=' for equality.
* "(x < 2000000 and x >= 10000) or (x >= 100 and x < 2000)"
* "x := 100000" is the same as "x == 100000"
*
* Since this is basic numerics only, we simply try to get away with
* replacing the variable values at the right positions and do an eval then.
*
* @package NumericSearchQuery
* @author Reini Urban
* @see SemanticAttributeSearchQuery
*/
class NumericSearchQuery
{
/**
* Create a new query.
* NumericSearchQuery("population > 20000 or population < 200", "population")
* NumericSearchQuery("population < 20000 and area > 1000000", array("population", "area"))
*
* With a single variable it is easy: The valid name must be matched elsewhere, just
* replace the given number in match in the query.
* ->match(2000)
*
* With matching a struct we need strict names, no * as name is allowed.
* So always when the placeholder is an array, the names of the target struct must match
* and all vars be defined. Use the method can_match($struct) therefore.
*
* @access public
* @param $search_query string A numerical query with placeholders as variable.
* @param $placeholders array or string All placeholders in the query must be defined
* here, and will be replaced by the matcher.
*/
function NumericSearchQuery($search_query, $placeholders)
{
// added some basic security checks against user input
$this->_query = $search_query;
$this->_placeholders = $placeholders;
// we should also allow the M_ constants
$this->_allowed_functions = explode(':', 'abs:acos:acosh:asin:asinh:atan2:atan:atanh:base_convert:bindec:ceil:cos:cosh:decbin:dechex:decoct:deg2rad:exp:expm1:floor:fmod:getrandmax:hexdec:hypot:is_finite:is_infinite:is_nan:lcg_value:log10:log1p:log:max:min:mt_getrandmax:mt_rand:mt_srand:octdec:pi:pow:rad2deg:rand:round:sin:sinh:sqrt:srand:tan:tanh');
$this->_allowed_operators = explode(',', '-,<,<=,>,>=,==,!=,*,+,/,(,),%,and,or,xor,<<,>>,===,!==,&,^,|,&&,||');
$this->_parser_check = array();
// check should be fast, so make a hash
foreach ($this->_allowed_functions as $f)
$this->_parser_check[$f] = 1;
foreach ($this->_allowed_operators as $f)
$this->_parser_check[$f] = 1;
if (is_array($placeholders))
foreach ($placeholders as $f)
$this->_parser_check[$f] = 1;
else $this->_parser_check[$placeholders] = 1;
// This is a speciality: := looks like the attribute definition and is
// therefore a dummy check for this definition.
// php-4.2.2 has a problem with /\b:=\b/ matching "population := 1223400"
$this->_query = preg_replace("/:=/", "==", $this->_query);
$this->_query = $this->check_query($this->_query);
}
function getType()
{
return 'numeric';
}
/**
* Check the symbolic definition query against unwanted functions and characters.
* "population < 20000 and area > 1000000" vs
* "area > 1000000 and mail($me,file("/etc/passwd"),...)"
* http://localhost/wikicvs/SemanticSearch?attribute=*&attr_op=<0 and find(1)>&s=-0.01&start_debug=1
*/
function check_query($query)
{
$tmp = $query; // check for all function calls, in case the tokenizer is not available.
while (preg_match("/([a-z][a-z0-9]+)\s*\((.*)$/i", $tmp, $m)) {
if (!in_array($m[1], $this->_allowed_functions)
and !in_array($m[1], $this->_allowed_operators)
) {
trigger_error("Illegal function in query: " . $m[1], E_USER_WARNING);
return '';
}
$tmp = $m[2];
}
// Strictly check for illegal functions and operators, which are no placeholders.
if (function_exists('token_get_all')) {
$parsed = token_get_all("$query?>");
foreach ($parsed as $x) { // flat, non-recursive array
if (is_string($x) and !isset($this->_parser_check[$x])) {
// single char op or name
trigger_error("Illegal string or operator in query: \"$x\"", E_USER_WARNING);
$query = '';
} elseif (is_array($x)) {
$n = token_name($x[0]);
if ($n == 'T_OPEN_TAG' or $n == 'T_WHITESPACE'
or $n == 'T_CLOSE_TAG' or $n == 'T_LNUMBER'
or $n == 'T_CONST' or $n == 'T_DNUMBER'
) continue;
if ($n == 'T_VARIABLE') { // but we do allow consts
trigger_error("Illegal variable in query: \"$x[1]\"", E_USER_WARNING);
$query = '';
}
if (is_string($x[1]) and !isset($this->_parser_check[$x[1]])) {
// multi-char char op or name
trigger_error("Illegal $n in query: \"$x[1]\"", E_USER_WARNING);
$query = '';
}
}
}
//echo "$query
";
//$this->_parse_token($parsed);
//echo "
\n";
//var_dump($parsed);
/*
"_x > 0" =>
{ T_OPEN_TAG ""} { T_STRING "_x"} { T_WHITESPACE " "} ">" { T_WHITESPACE " "} { T_LNUMBER "0"} { T_CLOSE_TAG "?>"}
Interesting: on-char ops, as ">" are not tokenized.
"_x <= 0"
{ T_OPEN_TAG "< ?" } { T_STRING "_x" } { T_WHITESPACE " " } { T_IS_SMALLER_OR_EQUAL "<=" } { T_WHITESPACE " " } { T_LNUMBER "0" } { T_CLOSE_TAG "?>" }
*/
} else {
// Detect illegal characters besides nums, words and ops.
// So attribute names can not be utf-8
$c = "/([^\d\w.,\s" . preg_quote(join("", $this->_allowed_operators), "/") . "])/";
if (preg_match($c, $query, $m)) {
trigger_error("Illegal character in query: " . $m[1], E_USER_WARNING);
return '';
}
}
return $query;
}
/**
* Check the bound, numeric-only query against unwanted functions and sideeffects.
* "4560000 < 20000 and 1456022 > 1000000"
*/
function _live_check()
{
// TODO: check $this->_workquery again?
return !empty($this->_workquery);
}
/**
* A numeric query can only operate with predefined variables. "x < 0 and y < 1"
*
* @return array The names as array of strings. => ('x', 'y') the placeholders.
*/
function getVars()
{
if (is_array($this->_placeholders)) return $this->_placeholders;
else return array($this->_placeholders);
}
/**
* Strip non-numeric chars from the variable (as the groupseperator) and replace
* it in the symbolic query for evaluation.
*
* @access private
* @param $value number A numerical value: integer, float or string.
* @param $x string The variable name to be replaced in the query.
* @return string
*/
function _bind($value, $x)
{
// TODO: check is_number, is_float, is_integer and do casting
$this->_bound[] = array('linkname' => $x,
'linkvalue' => $value);
$value = preg_replace("/[^-+0123456789.,]/", "", $value);
//$c = "/\b".preg_quote($x,"/")."\b/";
$this->_workquery = preg_replace("/\b" . preg_quote($x, "/") . "\b/", $value, $this->_workquery);
// FIXME: do again a final check. now only numbers and some operators are allowed.
return $this->_workquery;
}
/* array of successfully bound vars, and in case of success, the resulting vars
*/
function _bound()
{
return $this->_bound;
}
/**
* With an array of placeholders we need a hash to check against, if all required names are given.
* Purpose: Be silent about missing vars, just return false.
`*
* @access public
* @param $variable string or hash of name => value The keys must satisfy all placeholders in the definition.
* We want the full hash and not just the keys because a hash check is faster than the array of keys check.
* @return boolean
*/
function can_match(&$variables)
{
if (empty($this->_query))
return false;
$p =& $this->_placeholders;
if (!is_array($variables) and !is_array($p))
return $variables == $p; // This was easy.
// Check if all placeholders have definitions. can be overdefined but not underdefined.
if (!is_array($p)) {
if (!isset($variables[$p])) return false;
} else {
foreach ($p as $x) {
if (!isset($variables[$x])) return false;
}
}
return true;
}
/**
* We can match against a single variable or against a hash of variables.
* With one placeholder we need just a number.
* With an array of placeholders we need a hash.
*
* @access public
* @param $variable number or array of name => value The keys must satisfy all placeholders in the definition.
* @return boolean
*/
function match(&$variable)
{
$p =& $this->_placeholders;
$this->_workquery = $this->_query;
if (!is_array($p)) {
if (is_array($variable)) { // which var to match? we cannot decide this here
if (!isset($variable[$p]))
trigger_error("Required NumericSearchQuery->match variable $x not defined.", E_USER_ERROR);
$this->_bind($variable[$p], $p);
} else {
$this->_bind($variable, $p);
}
} else {
foreach ($p as $x) {
if (!isset($variable[$x]))
trigger_error("Required NumericSearchQuery->match variable $x not defined.", E_USER_ERROR);
$this->_bind($variable[$x], $x);
}
}
if (!$this->_live_check()) // check returned an error
return false;
$search = $this->_workquery;
$result = false;
//if (DEBUG & _DEBUG_VERBOSE)
// trigger_error("\$result = (boolean)($search);", E_USER_NOTICE);
// We might have a numerical problem:
// php-4.2.2 eval'ed as module: "9.636e+08 > 1000" false;
// php-5.1.2 cgi true, 4.2.2 cgi true
eval("\$result = (boolean)($search);");
if ($result and is_array($p)) {
return $this->_bound();
}
return $result;
}
}
////////////////////////////////////////////////////////////////
//
// Remaining classes are private.
//
////////////////////////////////////////////////////////////////
/**
* Virtual base class for nodes in a TextSearchQuery parse tree.
*
* Also serves as a 'VOID' (contentless) node.
*/
class TextSearchQuery_node
{
var $op = 'VOID';
var $_op = 0;
/**
* Optimize this node.
* @return object Optimized node.
*/
function optimize()
{
return $this;
}
/**
* @return regexp matching this node.
*/
function regexp()
{
return '';
}
/**
* @param bool True if this node has been negated (higher in the parse tree.)
* @return array A list of all non-negated words contained by this node.
*/
function highlight_words($negated = false)
{
return array();
}
function sql()
{
return $this->word;
}
function _sql_quote()
{
global $request;
$word = preg_replace('/(?=[%_\\\\])/', "\\", $this->word);
return $request->_dbi->_backend->qstr($word);
}
}
/**
* A word. Exact or substring?
*/
class TextSearchQuery_node_word
extends TextSearchQuery_node
{
var $op = "WORD";
var $_op = TSQ_TOK_WORD;
function TextSearchQuery_node_word($word)
{
$this->word = $word;
}
function regexp()
{
return '(?=.*\b' . preg_quote($this->word, '/') . '\b)';
}
function highlight_words($negated = false)
{
return $negated ? array() : array($this->word);
}
function sql()
{
return '%' . $this->_sql_quote($this->word) . '%';
}
}
class TextSearchQuery_node_all
extends TextSearchQuery_node
{
var $op = "ALL";
var $_op = TSQ_TOK_ALL;
function regexp()
{
return '(?=.*)';
}
function sql()
{
return '%';
}
}
class TextSearchQuery_node_starts_with
extends TextSearchQuery_node_word
{
var $op = "STARTS_WITH";
var $_op = TSQ_TOK_STARTS_WITH;
function regexp()
{
return '(?=.*\b' . preg_quote($this->word, '/') . ')';
}
function sql()
{
return $this->_sql_quote($this->word) . '%';
}
}
// ^word: full phrase starts with
class TextSearchQuery_phrase_starts_with
extends TextSearchQuery_node_starts_with
{
function regexp()
{
return '(?=^' . preg_quote($this->word, '/') . ')';
}
}
class TextSearchQuery_node_ends_with
extends TextSearchQuery_node_word
{
var $op = "ENDS_WITH";
var $_op = TSQ_TOK_ENDS_WITH;
function regexp()
{
return '(?=.*' . preg_quote($this->word, '/') . '\b)';
}
function sql()
{
return '%' . $this->_sql_quote($this->word);
}
}
// word$: full phrase ends with
class TextSearchQuery_phrase_ends_with
extends TextSearchQuery_node_ends_with
{
function regexp()
{
return '(?=' . preg_quote($this->word, '/') . '$)';
}
}
class TextSearchQuery_node_exact
extends TextSearchQuery_node_word
{
var $op = "EXACT";
var $_op = TSQ_TOK_EXACT;
function regexp()
{
return '(?=\b' . preg_quote($this->word, '/') . '\b)';
}
function sql()
{
return $this->_sql_squote($this->word);
}
}
class TextSearchQuery_node_regex // posix regex. FIXME!
extends TextSearchQuery_node_word
{
var $op = "REGEX"; // using REGEXP or ~ extension
var $_op = TSQ_TOK_REGEX;
function regexp()
{
return '(?=.*\b' . $this->word . '\b)';
}
function sql()
{
return $this->_sql_quote($this->word);
}
}
class TextSearchQuery_node_regex_glob
extends TextSearchQuery_node_regex
{
var $op = "REGEX_GLOB";
var $_op = TSQ_TOK_REGEX_GLOB;
function regexp()
{
return '(?=.*\b' . glob_to_pcre($this->word) . '\b)';
}
}
class TextSearchQuery_node_regex_pcre // how to handle pcre modifiers? /i
extends TextSearchQuery_node_regex
{
var $op = "REGEX_PCRE";
var $_op = TSQ_TOK_REGEX_PCRE;
function regexp()
{
return $this->word;
}
}
class TextSearchQuery_node_regex_sql
extends TextSearchQuery_node_regex
{
var $op = "REGEX_SQL"; // using LIKE
var $_op = TSQ_TOK_REGEX_SQL;
function regexp()
{
return str_replace(array("/%/", "/_/"), array(".*", "."), $this->word);
}
function sql()
{
return $this->word;
}
}
/**
* A negated clause.
*/
class TextSearchQuery_node_not
extends TextSearchQuery_node
{
var $op = "NOT";
var $_op = TSQ_TOK_NOT;
function TextSearchQuery_node_not($leaf)
{
$this->leaves = array($leaf);
}
function optimize()
{
$leaf = &$this->leaves[0];
$leaf = $leaf->optimize();
if ($leaf->_op == TSQ_TOK_NOT)
return $leaf->leaves[0]; // ( NOT ( NOT x ) ) -> x
return $this;
}
function regexp()
{
$leaf = &$this->leaves[0];
return '(?!' . $leaf->regexp() . ')';
}
function highlight_words($negated = false)
{
return $this->leaves[0]->highlight_words(!$negated);
}
}
/**
* Virtual base class for 'AND' and 'OR conjoins.
*/
class TextSearchQuery_node_binop
extends TextSearchQuery_node
{
var $_op = TSQ_TOK_BINOP;
function TextSearchQuery_node_binop($leaves)
{
$this->leaves = $leaves;
}
function _flatten()
{
// This flattens e.g. (AND (AND a b) (OR c d) e)
// to (AND a b e (OR c d))
$flat = array();
foreach ($this->leaves as $leaf) {
$leaf = $leaf->optimize();
if ($this->op == $leaf->op)
$flat = array_merge($flat, $leaf->leaves);
else
$flat[] = $leaf;
}
$this->leaves = $flat;
}
function optimize()
{
$this->_flatten();
assert(!empty($this->leaves));
if (count($this->leaves) == 1)
return $this->leaves[0]; // (AND x) -> x
return $this;
}
function highlight_words($negated = false)
{
$words = array();
foreach ($this->leaves as $leaf)
array_splice($words, 0, 0,
$leaf->highlight_words($negated));
return $words;
}
}
/**
* A (possibly multi-argument) 'AND' conjoin.
*/
class TextSearchQuery_node_and
extends TextSearchQuery_node_binop
{
var $op = "AND";
function optimize()
{
$this->_flatten();
// Convert (AND (NOT a) (NOT b) c d) into (AND (NOT (OR a b)) c d).
// Since OR's are more efficient for regexp matching:
// (?!.*a)(?!.*b) vs (?!.*(?:a|b))
// Suck out the negated leaves.
$nots = array();
foreach ($this->leaves as $key => $leaf) {
if ($leaf->_op == TSQ_TOK_NOT) {
$nots[] = $leaf->leaves[0];
unset($this->leaves[$key]);
}
}
// Combine the negated leaves into a single negated or.
if ($nots) {
$node = (new TextSearchQuery_node_not
(new TextSearchQuery_node_or($nots)));
array_unshift($this->leaves, $node->optimize());
}
assert(!empty($this->leaves));
if (count($this->leaves) == 1)
return $this->leaves[0]; // (AND x) -> x
return $this;
}
/* FIXME!
* Either we need all combinations of all words to be position independent,
* or we have to use multiple match calls for each AND
* (AND x y) => /(?(:x)(:y))|(?(:y)(:x))/
*/
function regexp()
{
$regexp = '';
foreach ($this->leaves as $leaf)
$regexp .= $leaf->regexp();
return $regexp;
}
}
/**
* A (possibly multi-argument) 'OR' conjoin.
*/
class TextSearchQuery_node_or
extends TextSearchQuery_node_binop
{
var $op = "OR";
function regexp()
{
// We will combine any of our direct descendents which are WORDs
// into a single (?=.*(?:word1|word2|...)) regexp.
$regexps = array();
$words = array();
foreach ($this->leaves as $leaf) {
if ($leaf->op == TSQ_TOK_WORD)
$words[] = preg_quote($leaf->word, '/');
else
$regexps[] = $leaf->regexp();
}
if ($words)
array_unshift($regexps,
'(?=.*' . $this->_join($words) . ')');
return $this->_join($regexps);
}
function _join($regexps)
{
assert(count($regexps) > 0);
if (count($regexps) > 1)
return '(?:' . join('|', $regexps) . ')';
else
return $regexps[0];
}
}
////////////////////////////////////////////////////////////////
//
// Parser:
// op's (and, or, not) are forced to lowercase in the tokenizer.
//
////////////////////////////////////////////////////////////////
class TextSearchQuery_Parser
{
/*
* This is a simple recursive descent parser, based on the following grammar:
*
* toplist :
* | toplist expr
* ;
*
*
* list : expr
* | list expr
* ;
*
* expr : atom
* | expr BINOP atom
* ;
*
* atom : '(' list ')'
* | NOT atom
* | WORD
* ;
*
* The terminal tokens are:
*
*
* and|or BINOP
* -|not NOT
* ( LPAREN
* ) RPAREN
* /[^-()\s][^()\s]* WORD
* /"[^"]*"/ WORD
* /'[^']*'/ WORD
*
* ^WORD TextSearchQuery_phrase_starts_with
* WORD* STARTS_WITH
* *WORD ENDS_WITH
* ^WORD$ EXACT
* * ALL
*/
function parse($search_expr, $case_exact = false, $regex = TSQ_REGEX_AUTO)
{
$this->lexer = new TextSearchQuery_Lexer($search_expr, $case_exact, $regex);
$this->_regex = $regex;
$tree = $this->get_list('toplevel');
// Assert failure when using the following URL in debug mode.
// /TitleSearch?action=FullTextSearch&s=WFXSSProbe'")/>&case_exact=1®ex=sql
// assert($this->lexer->eof());
unset($this->lexer);
return $tree;
}
function get_list($is_toplevel = false)
{
$list = array();
// token types we'll accept as words (and thus expr's) for the
// purpose of error recovery:
$accept_as_words = TSQ_TOK_NOT | TSQ_TOK_BINOP;
if ($is_toplevel)
$accept_as_words |= TSQ_TOK_LPAREN | TSQ_TOK_RPAREN;
while (($expr = $this->get_expr())
|| ($expr = $this->get_word($accept_as_words))) {
$list[] = $expr;
}
if (!$list) {
if ($is_toplevel)
return new TextSearchQuery_node;
else
return false;
}
if ($is_toplevel and count($list) == 1) {
if ($this->lexer->query_str[0] == '^')
return new TextSearchQuery_phrase_starts_with($list[0]->word);
else
return $list[0];
}
return new TextSearchQuery_node_and($list);
}
function get_expr()
{
if (($expr = $this->get_atom()) === false) // protect against '0'
return false;
$savedpos = $this->lexer->tell();
// Bug#1791564: allow string '0'
while (($op = $this->lexer->get(TSQ_TOK_BINOP)) !== false) {
if (!($right = $this->get_atom())) {
break;
}
if ($op == 'and')
$expr = new TextSearchQuery_node_and(array($expr, $right));
else {
assert($op == 'or');
$expr = new TextSearchQuery_node_or(array($expr, $right));
}
$savedpos = $this->lexer->tell();
}
$this->lexer->seek($savedpos);
return $expr;
}
function get_atom()
{
if ($atom = $this->get_word(TSQ_ALLWORDS)) // Bug#1791564 not involved: '*'
return $atom;
$savedpos = $this->lexer->tell();
if ($this->lexer->get(TSQ_TOK_LPAREN)) {
if (($list = $this->get_list()) && $this->lexer->get(TSQ_TOK_RPAREN)) {
return $list;
} else {
// Fix Bug#1792170
// Handle " ( " or "(test" without closing ")" as plain word
$this->lexer->seek($savedpos);
return new TextSearchQuery_node_word($this->lexer->get(-1));
}
} elseif ($this->lexer->get(TSQ_TOK_NOT)) {
if (($atom = $this->get_atom()))
return new TextSearchQuery_node_not($atom);
}
$this->lexer->seek($savedpos);
return false;
}
function get_word($accept = TSQ_ALLWORDS)
{
// Performance shortcut for ( and ). This is always false
if (!empty($this->lexer->tokens[$this->lexer->pos])) {
list ($type, $val) = $this->lexer->tokens[$this->lexer->pos];
if ($type == TSQ_TOK_LPAREN or $type == TSQ_TOK_RPAREN)
return false;
}
foreach (array("WORD", "STARTS_WITH", "ENDS_WITH", "EXACT",
"REGEX", "REGEX_GLOB", "REGEX_PCRE", "ALL") as $tok) {
$const = constant("TSQ_TOK_" . $tok);
// Bug#1791564: allow word '0'
if ($accept & $const and
(($word = $this->lexer->get($const)) !== false)
) {
// phrase or word level?
if ($tok == 'STARTS_WITH' and $this->lexer->query_str[0] == '^')
$classname = "TextSearchQuery_phrase_" . strtolower($tok);
elseif ($tok == 'ENDS_WITH' and
string_ends_with($this->lexer->query_str, '$')
)
$classname = "TextSearchQuery_phrase_" . strtolower($tok); else
$classname = "TextSearchQuery_node_" . strtolower($tok);
return new $classname($word);
}
}
return false;
}
}
class TextSearchQuery_Lexer
{
function TextSearchQuery_Lexer($query_str, $case_exact = false,
$regex = TSQ_REGEX_AUTO)
{
$this->tokens = $this->tokenize($query_str, $case_exact, $regex);
$this->query_str = $query_str;
$this->pos = 0;
}
function tell()
{
return $this->pos;
}
function seek($pos)
{
$this->pos = $pos;
}
function eof()
{
return $this->pos == count($this->tokens);
}
/**
* TODO: support more regex styles, esp. prefer the forced ones over auto
* re: and // stuff
*/
function tokenize($string, $case_exact = false, $regex = TSQ_REGEX_AUTO)
{
$tokens = array();
$buf = $case_exact ? ltrim($string) : strtolower(ltrim($string));
while (!empty($buf)) {
if (preg_match('/^([()])\s*/', $buf, $m)) {
$val = $m[1];
$type = $m[1] == '(' ? TSQ_TOK_LPAREN : TSQ_TOK_RPAREN;
} // * => ALL
elseif ($regex & (TSQ_REGEX_AUTO | TSQ_REGEX_POSIX | TSQ_REGEX_GLOB)
and preg_match('/^\*\s*/', $buf, $m)
) {
$val = "*";
$type = TSQ_TOK_ALL;
} // .* => ALL
elseif ($regex & (TSQ_REGEX_PCRE)
and preg_match('/^\.\*\s*/', $buf, $m)
) {
$val = ".*";
$type = TSQ_TOK_ALL;
} // % => ALL
elseif ($regex & (TSQ_REGEX_SQL)
and preg_match('/^%\s*/', $buf, $m)
) {
$val = "%";
$type = TSQ_TOK_ALL;
} // ^word
elseif ($regex & (TSQ_REGEX_AUTO | TSQ_REGEX_POSIX | TSQ_REGEX_PCRE)
and preg_match('/^\^([^-()][^()\s]*)\s*/', $buf, $m)
) {
$val = $m[1];
$type = TSQ_TOK_STARTS_WITH;
} // word*
elseif ($regex & (TSQ_REGEX_AUTO | TSQ_REGEX_POSIX | TSQ_REGEX_GLOB)
and preg_match('/^([^-()][^()\s]*)\*\s*/', $buf, $m)
) {
$val = $m[1];
$type = TSQ_TOK_STARTS_WITH;
} // *word
elseif ($regex & (TSQ_REGEX_AUTO | TSQ_REGEX_POSIX | TSQ_REGEX_GLOB)
and preg_match('/^\*([^-()][^()\s]*)\s*/', $buf, $m)
) {
$val = $m[1];
$type = TSQ_TOK_ENDS_WITH;
} // word$
elseif ($regex & (TSQ_REGEX_AUTO | TSQ_REGEX_POSIX | TSQ_REGEX_PCRE)
and preg_match('/^([^-()][^()\s]*)\$\s*/', $buf, $m)
) {
$val = $m[1];
$type = TSQ_TOK_ENDS_WITH;
} // ^word$
elseif ($regex & (TSQ_REGEX_AUTO | TSQ_REGEX_POSIX | TSQ_REGEX_PCRE)
and preg_match('/^\^([^-()][^()\s]*)\$\s*/', $buf, $m)
) {
$val = $m[1];
$type = TSQ_TOK_EXACT;
} elseif (preg_match('/^(and|or)\b\s*/i', $buf, $m)) {
$val = strtolower($m[1]);
$type = TSQ_TOK_BINOP;
} elseif (preg_match('/^(-|not\b)\s*/i', $buf, $m)) {
$val = strtolower($m[1]);
$type = TSQ_TOK_NOT;
} // "words "
elseif (preg_match('/^ " ( (?: [^"]+ | "" )* ) " \s*/x', $buf, $m)) {
$val = str_replace('""', '"', $m[1]);
$type = TSQ_TOK_WORD;
} // 'words '
elseif (preg_match("/^ ' ( (?:[^']+|'')* ) ' \s*/x", $buf, $m)) {
$val = str_replace("''", "'", $m[1]);
$type = TSQ_TOK_WORD;
} // word
elseif (preg_match('/^([^-()][^()\s]*)\s*/', $buf, $m)) {
$val = $m[1];
$type = TSQ_TOK_WORD;
} else {
assert(empty($buf));
break;
}
$buf = substr($buf, strlen($m[0]));
/* refine the simple parsing from above: bla*bla, bla?bla, ...
if ($regex and $type == TSQ_TOK_WORD) {
if (substr($val,0,1) == "^")
$type = TSQ_TOK_STARTS_WITH;
elseif (substr($val,0,1) == "*")
$type = TSQ_TOK_ENDS_WITH;
elseif (substr($val,-1,1) == "*")
$type = TSQ_TOK_STARTS_WITH;
}
*/
$tokens[] = array($type, $val);
}
return $tokens;
}
function get($accept)
{
if ($this->pos >= count($this->tokens))
return false;
list ($type, $val) = $this->tokens[$this->pos];
if (($type & $accept) == 0)
return false;
$this->pos++;
return $val;
}
}
// Local Variables:
// mode: php
// tab-width: 8
// c-basic-offset: 4
// c-hanging-comment-ender-p: nil
// indent-tabs-mode: nil
// End: