kmpMatcher = function( pattern, ignoreCase )
		{
			var overlap = [ -1 ];
			if ( ignoreCase )
				pattern = pattern.toLowerCase();
			for ( var i = 0 ; i < pattern.length ; i++ )
			{
				overlap.push( overlap[i] + 1 );
				while ( overlap[ i + 1 ] > 0
					&& pattern.charAt( i ) != pattern
						.charAt( overlap[ i + 1 ] - 1 ) )
					overlap[ i + 1 ] = overlap[ overlap[ i + 1 ] - 1 ] + 1;
			}

			this._ = {
				overlap : overlap,
				state : 0,
				ignoreCase : !!ignoreCase,
				pattern : pattern
			};
		}
Examination the occurrence of a word which implement KMP algorithm.