indexing
	description: "Packed boolean strings"
	names: packed_booleans
	access: index
	representation: array
	size: fixed

class interface
	BOOL_STRING

create 

	make (n: INTEGER)
			-- Allocate area of n booleans.
		require
			non_negative_size: n >= 0
		ensure
			correct_allocation: count = n

feature -- Initialization

	make (n: INTEGER)
			-- Allocate area of n booleans.
		require
			non_negative_size: n >= 0
		ensure
			correct_allocation: count = n
	
feature -- Access

	item (i: INTEGER): BOOLEAN
			-- Boolean at i-th position,
			-- beginning at left, 1 origin
		require
			index_large_enough: 1 <= i;
			index_small_enough: i <= count
	
feature -- Measurement

	count: INTEGER
			-- Number of boolean in the area.
	
feature -- Element change

	all_false
			-- Set all booleans to false.

	all_true
			-- Set all booleans to true.

	put (v: like item; i: INTEGER)
			-- Put boolean v at i-th position
			-- beginning at left, 1 origin.
		require
			index_large_enough: 1 <= i;
			index_small_enough: i <= count
	
feature -- Basic operations

	left_shifted (n: INTEGER): like Current
			-- Left shifted 'Current' set, by n positions
		require
			non_negative_shift: n >= 0

	right_shifted (n: INTEGER): like Current
			-- Right shifted 'Current' set, by n positions
		require
			non_negative_shift: n >= 0

	infix "and" (other: like Current): like Current
			-- Logical and of 'Current' and other
		require
			other_not_void: other /= void;
			same_size: other.count = count

	prefix "not ": like Current
			-- Negation of 'Current'

	infix "or" (other: like Current): like Current
			-- Logical or of 'Current' and other
		require
			other_not_void: other /= void;
			same_size: other.count = count

	infix "xor" (other: like Current): like Current
			-- Logical exclusive or of 'Current' and other
		require
			other_not_void: other /= void;
			same_size: other.count = count
	
end -- class BOOL_STRING