nl_tokens: For implementing reverse () on large sparse arrays .
pl_tokens: function SparseReverse ( array , len ) { var keys = GetSortedArrayKeys ( array , % GetArrayKeys ( array , len ) ) ; var high_counter = keys . length - 1 ; var low_counter = 0 ; while ( low_counter <= high_counter ) { var i = keys [ low_counter ] ; var j = keys [ high_counter ] ; var j_complement = len - j - 1 ; var low , high ; if ( j_complement <= i ) { high = j ; while ( keys [ -- high_counter ] == j ) { } low = j_complement ; } if ( j_complement >= i ) { low = i ; while ( keys [ ++ low_counter ] == i ) { } high = len - i - 1 ; } var current_i = array [ low ] ; if ( ! IS_UNDEFINED ( current_i ) || low in array ) { var current_j = array [ high ] ; if ( ! IS_UNDEFINED ( current_j ) || high in array ) { array [ low ] = current_j ; array [ high ] = current_i ; } else { array [ high ] = current_i ; delete <mask> [ low ] ; } } else { var current_j = array [ high ] ; if ( ! IS_UNDEFINED ( current_j ) || high in array ) { array [ low ] = current_j ; delete array [ high ] ; } } } }