Function cache

2.0.3/2.0.3.js:1171–1178

( key, value )

            var keys = [];

            function cache( key, value ) {
                // Use (key + " ") to avoid collision with native prototype properties (see Issue #157)
                if ( keys.push( key += " " ) > Expr.cacheLength ) {
                    // Only keep the most recent entries
                    delete cache[ keys.shift() ];
                }
                return (cache[ key ] = value);
            }
            return cache;
        }