| Class DT_DATE | |
note
description:
"Dates (Gregorian calendar)"
library: "Gobo Eiffel Time Library"
author: "Eric Bezault <ericb@gobosoft.com>"
copyright: "Copyright (c) 2000-2001, Eric Bezault and others"
license: "MIT License"
class interface
DT_DATE
inherit
DT_ABSOLUTE_TIME
COMPARABLE
HASHABLE
DT_DATE_VALUE
DT_GREGORIAN_CALENDAR
create
make (y, m, d: INTEGER) -- Create a new date. require m_large_enough: m >= January m_small_enough: m <= December d_large_enough: d >= 1 d_small_enough: d <= days_in_month (m, y) ensure year_set: year = y month_set: month = m day_set: day = dmake_from_day_count (d: INTEGER) -- Create a new date from the number -- of days since epoch (1 Jan 1970). ensure day_count_set: day_count = d
feature -- Access
year: INTEGER -- Year -- (From DT_DATE_VALUE.)month: INTEGER -- Month -- (From DT_DATE_VALUE.) ensure month_large_enough: Result >= January month_small_enough: Result <= Decemberday: INTEGER -- Day -- (From DT_DATE_VALUE.) ensure day_large_enough: Result >= 1 day_small_enough: Result <= days_in_month (month, year)year_day: INTEGER -- Day in current year ensure non_leap_year: not is_leap_year implies (Result >= 1 and Result <= Days_in_year) leap_year: is_leap_year implies (Result >= 1 and Result <= Days_in_leap_year)week_day: INTEGER -- Day in current week ensure valid_day: Result >= Sunday and Result <= Saturdayinfix "-" (other: like Current): like duration -- Duration between other and Current -- (From DT_ABSOLUTE_TIME.) require other_not_void: other /= Void ensure duration_not_void: Result /= Void definition: (other + Result).is_equal (Current)infix "+" (a_duration: like duration): like Current -- Addition of a_duration to Current -- (Create a new object at each call.) -- (From DT_ABSOLUTE_TIME.) require a_duration_not_void: a_duration /= Void ensure addition_not_void: Result /= Voidinfix "&d" (a_duration: like date_duration): like Current -- Addition of a_duration to current date -- (Create a new object at each call.) require a_duration_not_void: a_duration /= Void ensure addition_not_void: Result /= Voidduration (other: like Current): DT_DATE_DURATION -- Duration between other and curent date -- (From DT_ABSOLUTE_TIME.) require other_not_void: other /= Void ensure duration_not_void: Result /= Void definition: (other + Result).is_equal (Current) definite_duration: Result.is_definitecanonical_duration (other: like Current): like duration -- Canonical duration between other and current date require other_not_void: other /= Void ensure duration_not_void: Result /= Void canonical_duration: Result.is_canonical (other) definition: (other + Result).is_equal (Current)date_duration (other: like Current): DT_DATE_DURATION -- Duration between other and current date require other_not_void: other /= Void ensure date_duration_not_void: Result /= Void definite_duration: Result.is_definite definition: (other &d Result).is_equal (Current)day_count: INTEGER -- Number of days since epoch (1 Jan 1970)days_in_current_month: INTEGER -- Number of days in current month ensure at_least_one: Result >= 1 max_days_in_month: Result <= Max_days_in_monthdays_in_previous_month: INTEGER -- Number of days in previous month ensure at_least_one: Result >= 1 max_days_in_month: Result <= Max_days_in_monthhash_code: INTEGER -- Hash code value -- (From HASHABLE.) ensure good_hash_value: Result >= 0
feature -- Status report
is_leap_year: BOOLEAN
-- Is year a leap year?
feature -- Comparison
infix "<" (other: like Current): BOOLEAN
-- Is current date before other on the time axis?
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
asymmetric: Result implies not (other < Current)
infix "<=" (other: like Current): BOOLEAN
-- Is current object less than or equal to other?
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
definition: Result = ((Current < other) or is_equal (other))
infix ">=" (other: like Current): BOOLEAN
-- Is current object greater than or equal to other?
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
definition: Result = (other <= Current)
infix ">" (other: like Current): BOOLEAN
-- Is current object greater than other?
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
definition: Result = (other < Current)
is_equal (other: like Current): BOOLEAN
-- Is other attached to an object considered equal
-- to current object?
-- (From GENERAL.)
require
other_not_void: other /= Void
ensure
symmetric: Result implies other.is_equal (Current)
consistent: standard_is_equal (other) implies Result
trichotomy: Result = (not (Current < other) and not (other < Current))
max (other: like Current): like Current
-- The greater of current object and other
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
current_if_not_smaller: (Current >= other) implies (Result = Current)
other_if_smaller: (Current < other) implies (Result = other)
min (other: like Current): like Current
-- The smaller of current object and other
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
current_if_not_greater: (Current <= other) implies (Result = Current)
other_if_greater: (Current > other) implies (Result = other)
three_way_comparison (other: like Current): INTEGER
-- If current object equal to other, 0; if smaller,
-- -1; if greater, 1.
-- (From COMPARABLE.)
require
other_exists: other /= Void
ensure
equal_zero: (Result = 0) = is_equal (other)
smaller_negative: (Result = -1) = (Current < other)
greater_positive: (Result = 1) = (Current > other)
feature -- Duplication
copy (other: like Current)
-- Copy other to current date.
-- (From GENERAL.)
require
other_not_void: other /= Void
type_identity: same_type (other)
ensure
is_equal: is_equal (other)
feature -- Setting
set_date (a_date: DT_DATE) -- Set year, month and day from a_date. require a_date_not_void: a_date /= Void ensure year_set: year = a_date.year month_set: month = a_date.month day_set: day = a_date.dayset_year_month_day (y, m, d: INTEGER) -- Set year to y, month to m and day to d. require m_large_enough: m >= January m_small_enough: m <= December d_large_enough: d >= 1 d_small_enough: d <= days_in_month (m, y) ensure year_set: year = y month_set: month = m day_set: day = dset_year (y: INTEGER) -- Set year to y. require leap_year_aware: day <= days_in_month (month, y) ensure year_set: year = y same_month: month = old month same_day: day = old dayset_month (m: INTEGER) -- Set month to m. require m_large_enough: m >= January m_small_enough: m <= December leap_year_aware: day <= days_in_month (m, year) ensure month_set: month = m same_year: year = old year same_day: day = old dayset_day (d: INTEGER) -- Set day to d. require d_large_enough: d >= 1 d_small_enough: d <= days_in_month (month, year) ensure day_set: day = d same_year: year = old year same_month: month = old monthset_day_count (d: INTEGER) -- Set day_count to d. ensure day_count_set: day_count = d
feature -- Element change
add_duration (a_duration: like duration) -- Add a_duration to current date. -- (Add a_duration.year and a_duration.month first, then -- set day to day.min (days_in_month (new_month, new_year)) -- and finally add a_duration.day.) -- (From DT_ABSOLUTE_TIME.) require a_duration_not_void: a_duration /= Voidadd_date_duration (a_duration: like date_duration) -- Add a_duration to current date. -- (Add a_duration.year and a_duration.month first, then -- set day to day.min (days_in_month (new_month, new_year)) -- and finally add a_duration.day.) require a_duration_not_void: a_duration /= Voidadd_years_months_days (y, m, d: INTEGER) -- Add y years, m months and d days to current date. -- (Add y and m first, then set day to -- day.min (days_in_month (new_month, new_year)) -- and finally add d.)add_years (y: INTEGER) -- Add y years to current date. ensure day_adjusted: day = (old day).min (days_in_month (month, year))add_months (m: INTEGER) -- Add m months to current date. ensure day_adjusted: day = (old day).min (days_in_month (month, year))add_days (d: INTEGER) -- Add d days to current date.
feature -- Output
out: STRING -- Printable representation (yyyy/mm/dd) -- (From GENERAL.) ensure out_not_void: Result /= Voiddate_out: STRING -- Printable representation (yyyy/mm/dd) -- (From DT_DATE_VALUE.) ensure date_out_not_void: Result /= Voidappend_to_string (a_string: STRING) -- Append printable representation -- (yyyy/mm/dd) to a_string. -- (From DT_DATE_VALUE.) require a_string_not_void: a_string /= Voidappend_date_to_string (a_string: STRING) -- Append printable representation -- (yyyy/mm/dd) to a_string. -- (From DT_DATE_VALUE.) require a_string_not_void: a_string /= Void
feature -- Year
leap_year (y: INTEGER): BOOLEAN -- Is y a leap year? -- (From DT_GREGORIAN_CALENDAR.)Months_in_year: INTEGER -- Number of months in a year -- (From DT_GREGORIAN_CALENDAR.) ensure definition: Result = (December - Januray + 1)Days_in_year: INTEGER Days_in_leap_year: INTEGER -- Number of days in a (leap) year -- (From DT_GREGORIAN_CALENDAR.)Days_in_400_years: INTEGER Days_in_100_years: INTEGER Days_in_4_years: INTEGER Days_in_3_years: INTEGER Days_in_3_leap_years: INTEGER Days_in_2_years: INTEGER Days_in_2_leap_years: INTEGER -- Number of days in multiple years -- (From DT_GREGORIAN_CALENDAR.)
feature -- Month
January: INTEGER February: INTEGER March: INTEGER April: INTEGER May: INTEGER June: INTEGER July: INTEGER August: INTEGER September: INTEGER October: INTEGER November: INTEGER December: INTEGER -- Months -- (From DT_GREGORIAN_CALENDAR.)days_in_month (m, y: INTEGER): INTEGER -- Number of days in month m of year y -- (From DT_GREGORIAN_CALENDAR.) require m_large_enough: m >= January m_small_enough: m <= December ensure at_least_one: Result >= 1 max_days_in_month: Result <= Max_days_in_monthMax_days_in_month: INTEGER -- Maximum number of days in a month -- (From DT_GREGORIAN_CALENDAR.)days_at_month (m, y: INTEGER): INTEGER -- Number of days from beginning of year -- y until beginning of month m -- (From DT_GREGORIAN_CALENDAR.) require m_large_enough: m >= January m_small_enough: m <= December ensure days_positive: Result >= 0
feature -- Week day
Sunday: INTEGER Monday: INTEGER Tuesday: INTEGER Wednesday: INTEGER Thursday: INTEGER Friday: INTEGER Saturday: INTEGER -- Week days -- (From DT_GREGORIAN_CALENDAR.)Days_in_week: INTEGER -- Number of days in a week -- (From DT_GREGORIAN_CALENDAR.) ensure definition: Result = (Saturday - Sunday + 1)next_day (d: INTEGER): INTEGER -- Week day after d -- (From DT_GREGORIAN_CALENDAR.) require d_large_enough: d >= Sunday d_small_enough: d <= Saturday ensure sunday_definition: (d = Sunday) implies (Result = Monday) monday_definition: (d = Monday) implies (Result = Tuesday) tuesday_definition: (d = Tuesday) implies (Result = Wednesday) wednesday_definition: (d = Wednesday) implies (Result = Thursday) thursday_definition: (d = Thursday) implies (Result= Friday) friday_definition: (d = Friday) implies (Result = Saturday) saturday_definition: (d = Saturday) implies (Result = Sunday)previous_day (d: INTEGER): INTEGER -- Week day before d -- (From DT_GREGORIAN_CALENDAR.) require d_large_enough: d >= Sunday d_small_enough: d <= Saturday ensure sunday_definition: (d = Sunday) implies (Result = Saturday) monday_definition: (d = Monday) implies (Result = Sunday) tuesday_definition: (d = Tuesday) implies (Result = Monday) wednesday_definition: (d = Wednesday) implies (Result = Tuesday) thursday_definition: (d = Thursday) implies (Result= Wednesday) friday_definition: (d = Friday) implies (Result = Thursday) saturday_definition: (d = Saturday) implies (Result = Friday)
feature -- Time
Seconds_in_minute: INTEGER -- Number of seconds in a minute -- (From DT_GREGORIAN_CALENDAR.)Seconds_in_hour: INTEGER -- Number of seconds in an hour -- (From DT_GREGORIAN_CALENDAR.)Seconds_in_day: INTEGER -- Number of seconds in a day -- (From DT_GREGORIAN_CALENDAR.)Milliseconds_in_day: INTEGER -- Number of milliseconds in a day -- (From DT_GREGORIAN_CALENDAR.)Minutes_in_hour: INTEGER -- Number of minutes in an hour -- (From DT_GREGORIAN_CALENDAR.)Hours_in_day: INTEGER -- Number of hours in a day -- (From DT_GREGORIAN_CALENDAR.)
feature -- Epoch
Epoch_year: INTEGER Epoch_month: INTEGER Epoch_day: INTEGER -- Epoch date (1 Jan 1970) -- (From DT_GREGORIAN_CALENDAR.)epoch_days (y, m, d: INTEGER): INTEGER -- Number of days since epoch date (1 Jan 1970) -- (From DT_GREGORIAN_CALENDAR.) require m_large_enough: m >= January m_small_enough: m <= December d_large_enough: d >= 1 d_small_enough: d <= days_in_month (m, y)
invariant
irreflexive_comparison: not (Current < Current)
-- (From COMPARABLE.)
end -- class DT_DATE
|
Copyright © 2000-2001, Eric
Bezault mailto:ericb@gobosoft.com http://www.gobosoft.com Last Updated: 8 April 2001 |
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