any RegExp guru's able to help a guy out?

neh

I am implementing a boolean search capability for a search engine I have written and figure on using preg_match_all to get the various arguments

so far to get the boolean AND terms working with:

/\+{1}\s{0,}\w+\s*/

and boolean NOT terms working with:

/\-{1}\s{0,}\w+\s*/

but I am at a loss (after many hours scrabbling about trying to learn enough perl regularexpression to fo it ) at how to then match the boolean OR (basically just search strings NOT preceeded by a + or - and 0 or more spaces)

I've gone through several tries but none have been successful

if you know your regexp and its a no brainer - I'd really appreciate a tip

many thanks
Ant

mkili

I would solve this by exploding your search input on space, and build your query looping through the array:
- elements starting with - apend to $not_query ( $not_query .= "field NOT LIKE '% $el %' AND " )
- elements starting with + apend to $like_query ( $like_query .= "field LIKE '%$e%' AND " )
(the above two without the leading - or +)
- other elements go to $or_query ( $or_query .= "OR field LIKE '%$e%'" )
- get rid of last 4 chars from $not_query and $like_query
- then build your query:
$query="SELECT * FROM table WHERE ($not_query) AND ( $like_query ) $or_query"

(not tested)

neh

yeah I know how to build a parser thanks ..

i want to use regexp becuase its presumably quicker than doing the same logic in an interpreted script - (what with it being native compiled into the php runtime) ..

the existing class method I wrote is this

function regExp($raw)
		{
			//parse the search strings to create a regular expression for the mysql provider

		if (strlen($raw) == 0)
		{
			return " ";
		}

		$words = explode(" ", $raw);
		$index = 0;
		$reg = "";

		while ($index < sizeof($words)):
			$reg = $reg.(strlen($reg) == 0 ? "[[:<:]]" : "|[[:<:]]").$words[$index]."[[:>:]]";
			$index++;
		endwhile;

		return $reg;

	}

ah .. I just this minute thought of a quick way to do it .. thanks for your effort anyway