indexing
	description: "Formatter for integral numbers"
	names: format_integer

class interface
	FORMAT_INTEGER

create 

	make (w: INTEGER)
		require
			reasonable_field: w >= 1
		ensure
			blank_fill: fill_character = ' ';
			show_sign_negative: show_sign_negative;
			no_separator: no_separator;
			width_set: width = w;
			right_justified: right_justified;
			leading_sign: leading_sign

feature -- Initialization

	make (w: INTEGER)
		require
			reasonable_field: w >= 1
		ensure
			blank_fill: fill_character = ' ';
			show_sign_negative: show_sign_negative;
			no_separator: no_separator;
			width_set: width = w;
			right_justified: right_justified;
			leading_sign: leading_sign
	
feature -- Access

	bracketted_negative: BOOLEAN
			-- Enclose negative numbers in brackets?

	fill_character: CHARACTER
			-- Padding character.

	justification: INTEGER
			-- Where in the field the format goes.

	separator: CHARACTER
			-- Separator between 1000's of numbers.

	sign_format: INTEGER
			-- How the sign is formatted.

	sign_string: STRING
			-- Formatting details for the sign.

	trailing_sign: BOOLEAN
			-- Is the sign at the end?

	width: INTEGER
			-- Width of the field.
	
feature -- Status report

	centered: BOOLEAN
			-- Are numbers to be formatted centered?
		ensure
			Result = (justification = center_justification)

	ignore_sign: BOOLEAN
			-- Ignore the sign of a number?
		ensure
			Result = (sign_format = ignore_sign_value)

	leading_sign: BOOLEAN
			-- Is the sign leading?
		ensure
			Result = not trailing_sign

	left_justified: BOOLEAN
			-- Are numbers to be formatted with spaces on the right?
		ensure
			Result = (justification = left_justification)

	no_separator: BOOLEAN
			-- Is there a separator?
		ensure
			Result = (separator = '%U')

	not_justified: BOOLEAN
			-- Are numbers to be formatted in smallest string possible
		ensure
			Result = (justification = no_justification)

	right_justified: BOOLEAN
			-- Are numbers to be formatted with spaces on the left?
		ensure
			Result = (justification = right_justification)

	show_sign: BOOLEAN
			-- Are numbers to show sign whether positive or negative?
		ensure
			Result = (sign_format = show_sign_value)

	show_sign_negative: BOOLEAN
			-- Are numbers to show sign only when negative?
		ensure
			Result = (sign_format = sign_negative_value)

	show_sign_positive: BOOLEAN
			-- Are numbers to show sign only when positive?
		ensure
			Result = (sign_format = sign_positive_value)
	
feature -- Status setting

	asterisk_fill
			-- Fill numbers with asterisks.
		ensure
			fill_character = '*'

	blank_fill
			-- Fill numbers with blanks.
		ensure
			fill_character = ' '

	bracket_negative
			-- Bracket negative numbers.
		ensure
			bracketted_negative

	center_justify
			-- Put padding on right and left
		ensure
			centered

	comma_separate
			-- Set separator to comma.
		ensure
			separator = ','

	dollar_fill
			-- Fill numbers with dollars.
		ensure
			fill_character = '$'

	dot_separate
			-- Set separator to period.
		ensure
			separator = '.'

	left_justify
			--Put padding on right
		ensure
			left_justified

	no_justify
			-- Always return the smallest string possible
		ensure
			not_justified

	remove_separator
			-- Remove the separator.
		ensure
			separator = '%U'

	right_justify
			-- Put padding on left
		ensure
			right_justified

	set_fill (c: CHARACTER)
			-- Fill numbers with c
		ensure
			fill_character = c

	set_separator (c: CHARACTER)
			-- Set the separator to c
		ensure
			separator = c

	set_sign (s: STRING)
			-- Set sign values for positive, zero, negative
			-- All values must be the same length.
			-- Stored as negative, zero, positive.
		require
			s /= void;
			s.count >= 3;
			s.count \\ 3 = 0
		ensure
			sign_string.is_equal (s)

	set_width (w: INTEGER)
			-- Set width to w
		require
			wide_enough: w >= 1
		ensure
			width = w

	sign_cr_dr
			-- Set sign for CR/DR
		ensure
			sign_string.is_equal ("CR  DR")

	sign_dr_cr
			-- Set sign for DR/CR
		ensure
			sign_string.is_equal ("DR  CR")

	sign_floating_dollar
			-- Set sign for floating dollar.
		ensure
			sign_string.is_equal ("$$$")

	sign_floating_dollar_signed
			-- Set sign for floating dollar include sign.
		ensure
			sign_string.is_equal ("-$ $+$")

	sign_ignore
			-- Do not show sign.
		ensure
			ignore_sign

	sign_leading
			-- Set the sign to lead
		ensure
			leading_sign

	sign_negative_only
			-- Show sign for negative numbers only.
		ensure
			show_sign_negative

	sign_normal
			-- Set sign for - and +.
		ensure
			sign_string.is_equal ("- +")

	sign_positive_only
			-- Show sign for positive numbers only.
		ensure
			show_sign_positive

	sign_show
			-- Show sign for all numbers.
		ensure
			show_sign

	sign_trailing
			-- Set the sign to trail
		ensure
			trailing_sign

	unbracket_negative
			-- Do not bracket negative numbers.
		ensure
			not bracketted_negative

	underscore_separate
			-- Set separator to underscore.
		ensure
			separator = '_'

	zero_fill
			-- Fill numbers with zeros.
		ensure
			fill_character = '0'
	
feature -- Conversion

	formatted (i: INTEGER): STRING
			-- Format the integer.
		ensure
			exists: Result /= void;
			correct_length: not_justified or Result.count >= width
	
invariant

		-- from GENERAL
	reflexive_equality: standard_is_equal (Current);
	reflexive_conformance: conforms_to (Current);
	sign_string_constraint: sign_string /= void;
	wide_enough: width >= 1;
	no_justification <= justification and justification <= right_justification;

end -- class FORMAT_INTEGER