New subject: TZ-Olson updates to support Windows (was: The Trunk: Chronology-Core-dtl.85.mcz)

8 Jul 2023


      David T. Lewis uploaded a new version of Chronology-Core to project The Trunk:
http://source.squeak.org/trunk/Chronology-Core-dtl.85.mcz
==================== Summary ====================
Name: Chronology-Core-dtl.85
Author: dtl
Time: 1 July 2023, 9:01:03.976799 pm
UUID: bdd66b0f-97e1-4fd5-bca6-4194eaf60096
Ancestors: Chronology-Core-mt.82
Establish protocol for aTimeZone offsetAt: aDateAndTime. Let TimeZone be abstract and let FixedTimeZone implement the previous behavior with offset represented as a constant (no DST transition support). Other packages (e.g. TZ-Olson) may implement concrete TimeZone with DST support.
Save existing TimeZone instances in the package preamble and migrate them to FixedTimeZone in the postscript.
=============== Diff against Chronology-Core-mt.82 ===============
Item was added:
+ (PackageInfo named: 'Chronology-Core') preamble: '"below, add code to be run before the loading of this package"
+ 
+ "Remember all instances of TimeZone. These will become FixedTimeZone in the postscript"
+ TimeZone instSize = 3 ifTrue: [
+ 	Smalltalk at: #TimeZoneInstances put:
+ 		(Dictionary newFrom: (
+ 			TimeZone allInstances collect: [:tz |
+ 				tz -> { tz offset . tz name . tz abbreviation }]))].
+ '!
Item was changed:
  ----- Method: DateAndTime class>>localOffset: (in category 'squeak protocol') -----
  localOffset: aDuration
    "Override the local time zone (for testing). This disables the #automaticTimezone: preference"
+ 	self localTimeZone: (FixedTimeZone offset: aDuration name: 'Local Time (override)' abbreviation: 'LTO').
- 	self localTimeZone: (TimeZone offset: aDuration name: 'Local Time (override)' abbreviation: 'LTO').
  !
Item was changed:
  ----- Method: DateAndTime class>>now (in category 'ansi protocol') -----
  now
+ 	"Answer time now as reported by #primitiveUtcWithOffset. If the automaticTimeZone
+ 	preference is false, use the offset provided by LocalTimeZone rather than the offset
+ 	provided by the primitive."
- 	"Answer time now as reported by #primitiveUtcWithOffset. If the primitive is not
- 	available, answer the Posix epoch GMT."
self automaticTimezone
    	ifTrue: [ ^ self basicNew initializeFromPrimitive ]
    	ifFalse: [ | timeArray |
    		timeArray := Time posixMicrosecondClockWithOffset.
    		^ self utcMicroseconds: timeArray first offset: self localOffsetSeconds ]
  !
Item was added:
+ TimeZone subclass: #FixedTimeZone
+ 	instanceVariableNames: 'offset abbreviation name'
+ 	classVariableNames: ''
+ 	poolDictionaries: 'ChronologyConstants'
+ 	category: 'Chronology-Core'!
+ 
+ !FixedTimeZone commentStamp: 'dtl 6/20/2023 08:07' prior: 0!
+ FixedTimeZone is a simple class to collect the information identifying a UTC time zone. It is typically used in unit tests to specify specific time zone offsets.
+ 
+ offset			-	Duration	- the time zone's offset from UTC
+ abbreviation	-	String		- the abbreviated name for the time zone.
+ name			-	String		- the name of the time zone.
+ 
+ StaticTimeZone class >> #timeZones returns an array of the known time zones
+ StaticTimeZone class >> #default returns the default time zone (Greenwich Mean Time)
+ !
Item was added:
+ ----- Method: FixedTimeZone class>>allTimeZones (in category 'accessing') -----
+ allTimeZones
+ 
+ 	^ self timeZones , self timeZonesDST!
Item was added:
+ ----- Method: FixedTimeZone class>>default (in category 'accessing') -----
+ default
+ 	"Answer the default time zone - GMT"
+ 
+ 	^ self timeZones detect: [ :tz | tz offset = Duration zero ]!
Item was added:
+ ----- Method: FixedTimeZone class>>offset:name:abbreviation: (in category 'instance creation') -----
+ offset: aDuration name: aName abbreviation: anAbbreviation
+ 
+ 	^ self new
+ 		offset: aDuration;
+ 		name: aName;
+ 		abbreviation: anAbbreviation;
+ 		yourself
+ !
Item was added:
+ ----- Method: FixedTimeZone class>>timeZones (in category 'accessing') -----
+ timeZones
+ 	^{
+ 		self offset:  0 hours name: 'Universal Time' abbreviation: 'UTC'.
+ 		self offset:  0 hours name: 'Greenwich Mean Time' abbreviation: 'GMT'.
+ 		self offset:  1 hours name: 'Central European Time' abbreviation: 'CET'.
+ 		self offset:  2 hours name: 'South African Standard Time' abbreviation: 'SAST'.
+ 		self offset: -8 hours name: 'Pacific Standard Time' abbreviation: 'PST'.
+ 		self offset: -7 hours name: 'Mountain Standard Time' abbreviation: 'MST'.
+ 		self offset: -6 hours name: 'Central Standard Time' abbreviation: 'CST'.
+ 		self offset: -5 hours name: 'Eastern Standard Time' abbreviation: 'EST'.
+ 	}!
Item was added:
+ ----- Method: FixedTimeZone class>>timeZonesDST (in category 'accessing') -----
+ timeZonesDST
+ 	^{
+ 		self offset:  1 hours name: 'British Summer Time' abbreviation: 'BST'.
+ 		self offset:  2 hours name: 'Central European Summer Time' abbreviation: 'CEST'.
+ 		self offset: -7 hours name: 'Pacific Daylight Time' abbreviation: 'PDT'.
+ 		self offset: -6 hours name: 'Mountain Daylight Time' abbreviation: 'MDT'.
+ 		self offset: -5 hours name: 'Central Daylight Time' abbreviation: 'CDT'.
+ 		self offset: -4 hours name: 'Eastern Daylight Time' abbreviation: 'EDT'.
+ 	}!
Item was added:
+ ----- Method: FixedTimeZone>>abbreviation (in category 'accessing') -----
+ abbreviation
+ 
+ 	^ abbreviation!
Item was added:
+ ----- Method: FixedTimeZone>>abbreviation: (in category 'accessing') -----
+ abbreviation: aString
+ 
+ 	abbreviation := aString!
Item was added:
+ ----- Method: FixedTimeZone>>name (in category 'accessing') -----
+ name
+ 
+ 	^ name!
Item was added:
+ ----- Method: FixedTimeZone>>name: (in category 'accessing') -----
+ name: aString
+ 
+ 	name := aString!
Item was added:
+ ----- Method: FixedTimeZone>>offset: (in category 'accessing') -----
+ offset: aDuration
+ 
+ 	offset := aDuration
+ !
Item was added:
+ ----- Method: FixedTimeZone>>offsetAt: (in category 'accessing') -----
+ offsetAt: dateAndTime
+ 	"A FixedTimeZone has a constant offset, ignoring daylight savings time transitions"
+ 
+ 	^ offset
+ !
Item was added:
+ ----- Method: FixedTimeZone>>printOn: (in category 'private') -----
+ printOn: aStream
+ 
+ 	super printOn: aStream.
+ 	aStream
+ 		nextPut: $(;
+ 		nextPutAll: self abbreviation;
+ 		nextPut: $)!
Item was changed:
  Object subclass: #TimeZone
+ 	instanceVariableNames: ''
- 	instanceVariableNames: 'offset abbreviation name'
    classVariableNames: ''
    poolDictionaries: 'ChronologyConstants'
    category: 'Chronology-Core'!
+ !TimeZone commentStamp: 'dtl 6/15/2023 22:27' prior: 0!
+ A TimeZone answers the UTC offset for a DateAndTime based on local rules for a geographic region. For each regional time zone, the UTC offset varies as a function of the DateAndTime, notably in support of daylight savings time changes. The UTC offset for a TimeZone also may change over time as local rules are updated for various regions and political jurisdictions.
- !TimeZone commentStamp: 'dtl 7/11/2009 15:03' prior: 0!
- TimeZone is a simple class to colect the information identifying a UTC time zone.
+ Concrete subclasses are expected to implement UTC offset rules. The simple case of FixedTimeZone implements a time zone with constant offset, which is useful for unit test support.!
- offset			-	Duration	- the time zone's offset from UTC
- abbreviation	-	String		- the abbreviated name for the time zone.
- name			-	String		- the name of the time zone.
- 
- TimeZone class >> #timeZones returns an array of the known time zones
- TimeZone class >> #default returns the default time zone (Grenwich Mean Time)
- !
Item was added:
+ ----- Method: TimeZone class>>allForOffset: (in category 'accessing') -----
+ allForOffset: aDuration
+ 
+ 	^ self allTimeZones select: [:ea | ea offset = aDuration]!
Item was added:
+ ----- Method: TimeZone class>>allTimeZones (in category 'accessing') -----
+ allTimeZones
+ 	"Various concrete implementations may be available. These may include a
+ 	simple StaticTimeZone or e.g. the TZ-Olson time zone tables with daylight
+ 	savings time offset transitions."
+ 
+ 	^ self allSubclasses
+ 		inject: OrderedCollection new
+ 		into: [ :result :cls |
+ 			(cls class includesLocalSelector: #allTimeZones)
+ 				ifTrue: [result addAll: cls allTimeZones].
+ 			result].
+ !
Item was changed:
  ----- Method: TimeZone class>>default (in category 'accessing') -----
  default
    "Answer the default time zone - GMT"
+ 	^ FixedTimeZone default!
- 	^ self timeZones detect: [ :tz | tz offset = Duration zero ]!
Item was removed:
- ----- Method: TimeZone class>>offset:name:abbreviation: (in category 'instance creation') -----
- offset: aDuration name: aName abbreviation: anAbbreviation
- 
- 	^ self new
- 		offset: aDuration;
- 		name: aName;
- 		abbreviation: anAbbreviation;
- 		yourself
- !
Item was removed:
- ----- Method: TimeZone class>>timeZones (in category 'accessing') -----
- timeZones
- 	^{
- 		self offset:  0 hours name: 'Universal Time' abbreviation: 'UTC'.
- 		self offset:  0 hours name: 'Greenwich Mean Time' abbreviation: 'GMT'.
- 		self offset:  1 hours name: 'Central European Time' abbreviation: 'CET'.
- 		self offset:  2 hours name: 'South African Standard Time' abbreviation: 'SAST'.
- 		self offset: -8 hours name: 'Pacific Standard Time' abbreviation: 'PST'.
- 		self offset: -7 hours name: 'Mountain Standard Time' abbreviation: 'MST'.
- 		self offset: -6 hours name: 'Central Standard Time' abbreviation: 'CST'.
- 		self offset: -5 hours name: 'Eastern Standard Time' abbreviation: 'EST'.
- 	}!
Item was removed:
- ----- Method: TimeZone class>>timeZonesDST (in category 'accessing') -----
- timeZonesDST
- 	^{
- 		self offset:  1 hours name: 'British Summer Time' abbreviation: 'BST'.
- 		self offset:  2 hours name: 'Central European Summer Time' abbreviation: 'CEST'.
- 		self offset: -7 hours name: 'Pacific Daylight Time' abbreviation: 'PDT'.
- 		self offset: -6 hours name: 'Mountain Daylight Time' abbreviation: 'MDT'.
- 		self offset: -5 hours name: 'Central Daylight Time' abbreviation: 'CDT'.
- 		self offset: -4 hours name: 'Eastern Daylight Time' abbreviation: 'EDT'.
- 	}!
Item was changed:
  ----- Method: TimeZone>>abbreviation (in category 'accessing') -----
  abbreviation
+ 	^ self subclassResponsibility!
- 	^ abbreviation!
Item was removed:
- ----- Method: TimeZone>>abbreviation: (in category 'accessing') -----
- abbreviation: aString
- 
- 	abbreviation := aString!
Item was changed:
  ----- Method: TimeZone>>name (in category 'accessing') -----
  name
+ 	^ self subclassResponsibility!
- 	^ name!
Item was removed:
- ----- Method: TimeZone>>name: (in category 'accessing') -----
- name: aString
- 
- 	name := aString!
Item was changed:
  ----- Method: TimeZone>>offset (in category 'accessing') -----
  offset
+ 	"Answer the current offset"
+ 	^ self offsetAt: DateAndTime basicNew initializeFromPrimitive
- 	^ offset
  !
Item was removed:
- ----- Method: TimeZone>>offset: (in category 'accessing') -----
- offset: aDuration
- 
- 	offset := aDuration
- !
Item was added:
+ ----- Method: TimeZone>>offsetAt: (in category 'accessing') -----
+ offsetAt: dateAndTime
+ 
+ 	^ self subclassResponsibility
+ !
Item was removed:
- ----- Method: TimeZone>>printOn: (in category 'private') -----
- printOn: aStream
- 
- 	super printOn: aStream.
- 	aStream
- 		nextPut: $(;
- 		nextPutAll: self abbreviation;
- 		nextPut: $)!
Item was changed:
+ (PackageInfo named: 'Chronology-Core') postscript: '"Let all old instances of TimeZone become FixedTimeZone"
+ (Smalltalk globals removeKey: #TimeZoneInstances ifAbsent: [])
+ 	ifNotNil: [ :instanceData | 
+ 		instanceData keysAndValuesDo: [ :instance :data | | newInstance |
+ 			newInstance := FixedTimeZone
+ 				offset: data first
+ 				name: data second
+ 				abbreviation: data third.
+ 			instance becomeForward: newInstance ]].
+ '!
- (PackageInfo named: 'Chronology-Core') postscript: 'Smalltalk removeFromStartUpList: DateAndTime'!