import ceylon.time.base { Range, milliseconds, UnitOfDate, days, UnitOfYear, UnitOfMonth, UnitOfDay } import ceylon.time.internal { _gap = gap, _overlap = overlap } "Implementation of [[Range]] and allows easy iteration between [[Date]] types. Provides all power of [[Iterable]] features and complements with: * Easy way to recover [[Period]] * Easy way to recover [[Duration]] * Recover the overlap between [[DateRange]] types * Recover the gap between [[DateRange]] types * Allows customized way to iterate as navigate between values by [[UnitOfDate]] cases " see(`interface Range`) shared class DateRange( from, to, step = days ) satisfies Range<Date, UnitOfDate> { "The first Element returned by the iterator, if any. This should always produce the same value as `iterable.iterator().head`. It also represents the _caller_ that created the Range: Example: today().to(tomorrow) -> in this case today() is the caller/creator of the range." shared actual Date from; "The limit of the Range where. Example: Given: today().to(tomorrow) then tomorrow is the _to_ element. Given: tomorrow.to(today()) then today() is the _to_ element." shared actual Date to; "Customized way to iterate over each element, it does not interfer in _from_ and _to_ fields, but it does not guarantee that _to_ will be included in iterator." shared actual UnitOfDate step; "Returns the Period between _from_ and _to_ fields. Example: Given: today().to(tomorrow).duration then duration is 1 day. Given: tomorrow().to(today).duration then duration is -1 day." shared actual Period period => from.periodTo(to); "Returns the Duration between _from_ and _to_ fields. Example: Given: today().to(tomorrow).duration then duration is 86400000 milliseconds. Given: tomorrow().to(today).duration then duration is -86400000 milliseconds." shared actual Duration duration => Duration((to.dayOfEra - from.dayOfEra) * milliseconds.perDay); "Returns true if both: this and other are same type and have equal fields _from_ and _to_." shared actual Boolean equals( Object other ) => (super of Range<Date, UnitOfDate>).equals(other); "This implementation respect the constraint that if `x==y` then `x.hash==y.hash`." shared actual Integer hash => (super of Range<Date, UnitOfDate>).hash; "Returns empty or a new Range: - Each Range is considered a _set_ then [A..B] is equivalent to [B..A] - The precision is based on the lowest unit - When the new Range exists it will follow these rules:\n Given: [A..B] overlap [C..D]\n When: AB < CD\n [1..6] overlap [3..9] = [3,6]\n [1..6] overlap [9..3] = [3,6]\n [6..1] overlap [3..9] = [3,6]\n [6..1] overlap [9..3] = [3,6]\n\n Given: [A..B] overlap [C..D]\n When: AB > CD\n [3..9] overlap [1..6] = [3,6]\n [3..9] overlap [6..1] = [3,6]\n [9..3] overlap [1..6] = [3,6]\n [9..3] overlap [6..1] = [3,6]" shared actual DateRange|Empty overlap(Range<Date, UnitOfDate> other) { value response = _overlap([from,to], [other.from, other.to]); if ( is [Date,Date] response) { return DateRange(response[0], response[1]); } assert( is Empty response); return response; } "Returns empty or a new Range: - Each Range is considered a _set_ then [A..B] is equivalent to [B..A] - The precision is based on the lowest unit - When the new Range exists it will follow these rules:\n Given: [A..B] gap [C..D]\n When: AB < CD\n [1..2] gap [5..6] = (2,5)\n [1..2] gap [6..5] = (2,5)\n [2..1] gap [5..6] = (2,5)\n [2..1] gap [6..5] = (2,5)\n\n Given: [A..B] gap [C..D]\n When: AB > CD\n [5..6] gap [1..2] = (2,5)\n [5..6] gap [2..1] = (2,5)\n [6..5] gap [1..2] = (2,5)\n [6..5] gap [2..1] = (2,5)" shared actual DateRange|Empty gap( Range<Date, UnitOfDate> other ) { value response = _gap([from,to], [other.from, other.to]); switch( response ) case( is [Date,Date] ) { return response[0].successor < response[1] then DateRange(response[0].successor, response[1].predecessor) else []; } case( is Empty ) { return response; } } "An iterator for the elements belonging to this container. where each jump is based on actual step of this Range." shared actual Iterator<Date> iterator() { object listIterator satisfies Iterator<Date> { variable Integer count = 0; shared actual Date|Finished next() { value date = from > to then previousByStep(count++) else nextByStep(count++); value continueLoop = from <= to then date <= to else date >= to; return continueLoop then date else finished; } } return listIterator; } "Define how this Range will get next or previous element while iterating." shared actual DateRange stepBy( UnitOfDate step ) { return step == this.step then this else DateRange(from, to, step); } "The iteration for each element should always start from same point, this way is possible to not suffer with different number of days in months." Date nextByStep( Integer jump = 1 ) { switch( step ) case( is UnitOfYear ) { return from.plusYears(jump); } case( is UnitOfMonth ) { return from.plusMonths(jump); } case( is UnitOfDay ) { return from.plusDays(jump); } } "The iteration for each element should always start from same point, this way is possible to not suffer with different number of days in months." Date previousByStep( Integer jump = 1 ) { switch( step ) case( is UnitOfYear ) { return from.minusYears(jump); } case( is UnitOfMonth ) { return from.minusMonths(jump); } case( is UnitOfDay ) { return from.minusDays(jump); } } }