- Pharo-users - lists.pharo.org

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by Paul DeBruicker

Tim Mackinnon wrote > I am also wondering if the issue with Timespan is concerning - I was > surprised that putting a start and end date left me something that didnât > answer my end date presumably down to rounding when itâs converted down to > a duration (making me wonder if its better to keep a start and end date > and calculate the duration on the fly). > > Tim The Timespans are half open intervals. (https://en.wikipedia.org/wiki/Interval_(mathematics)) Friday July 21st ends at 11:59:59.99999999999... etc etc etc ...9999PM and the 22nd starts at 12:00AM If Timespans were closed intervals like you expect then we'd be out of whack with our corner of the universe. That extra clock tick adds complexity. But I add a method to my image called #displayEnd because I also want them to print 3PM-4PM and not 3PM-3:59:59.999999999PM and use that in my print statements and rendering for Seaside. displayEnd ^ start + duration -- View this message in context: http://forum.world.st/How-to-calculate-someone-s-age-elegantly-Does-Duratio… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

July 21, 2017

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by Esteban A. Maringolo

I remember this was discussed before in the mailing list, not in the context of age calculation, but regarding the offset/duration vs calendar based dates handling. Pharo's core date classes are "incremental", which isn't suited for calendar sensitive calculations. Java core class for those calculations is the java.util.Calendar class which is "field" based. See http://forum.world.st/Interesting-Date-Time-Thread-on-Squeak-Dev-tp4778652p… Esteban A. Maringolo 2017-07-21 12:16 GMT-03:00 Tim Mackinnon <tim(a)testit.works>: > I hadnât heard of that library - looks like one to keep in the back of my mind for more serious date related work. > > I do think that age or ageOn: should be in the standard core particularly when we have so many date and duration related classes - but Iâm not sure what the feeling is about adding methods. Certainly the group I saw learning smalltalk were very surprised it wasnât there particularly when they saw the rich models we do have. > > I am also wondering if the issue with Timespan is concerning - I was surprised that putting a start and end date left me something that didnât answer my end date presumably down to rounding when itâs converted down to a duration (making me wonder if its better to keep a start and end date and calculate the duration on the fly). >> On 21 Jul 2017, at 13:58, Esteban A. Maringolo <emaringolo(a)gmail.com> wrote: >> You might consider a full-fledged framework for it like Chalten: >> https://github.com/ba-st/chalten

July 21, 2017

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by Tim Mackinnon

I hadnât heard of that library - looks like one to keep in the back of my mind for more serious date related work. I do think that age or ageOn: should be in the standard core particularly when we have so many date and duration related classes - but Iâm not sure what the feeling is about adding methods. Certainly the group I saw learning smalltalk were very surprised it wasnât there particularly when they saw the rich models we do have. I am also wondering if the issue with Timespan is concerning - I was surprised that putting a start and end date left me something that didnât answer my end date presumably down to rounding when itâs converted down to a duration (making me wonder if its better to keep a start and end date and calculate the duration on the fly). Tim > On 21 Jul 2017, at 13:58, Esteban A. Maringolo <emaringolo(a)gmail.com> wrote: > > Tim, > > You might consider a full-fledged framework for it like Chalten: > https://github.com/ba-st/chalten > > I don't know how it handles timezones, because the age calculation > might get trickier if you consider also the time of birth and you're > querying it from a different timezone ;-) > > Regards! > > Esteban A. Maringolo > > > 2017-07-21 6:09 GMT-03:00 K K Subbu <kksubbu.ml(a)gmail.com>: >> I suppose no one needed it that badly ;-). Age is the difference in years >> except when the given date's julian is less than self's julian when it is >> less by 1, so the code can be simplified to: >> >> ^aDate year - self year - >> (aDate dayOfYear < self dayOfYear) ifTrue: [ 1 ] ifFalse: [ 0 ]) >> >> BTW, the code has an off-by-one error. +1 should be dropped in first age >> assignment. >> >> Regards .. Subbu >> >> >> On Friday 21 July 2017 12:55 PM, Tim Mackinnon wrote: >>> >>> Yes that's a good solution, however I'm really surprised that with the >>> plethora of dates, durations, timespans (we are well served with a very rich >>> time and date domain) that this isn't already in the image? >>> >>> It seems very surprising. In fact the group I was working with (other >>> language programmers) kept looking and looking for something as they felt >>> certain they had overlooked it given all those promising classes. >>> >>> I'm curious why it's not in there? And would we also expect to find its >>> equivalent on a timespan (maybe delegating back to this date method? This >>> assumes that timespan can be fixed as it loses precision unexpectedly). >>> >>> Thanks for the reply. >>> >>> Tim >>> >>> >>> >>> Sent from my iPhone >>> >>>> On 21 Jul 2017, at 06:41, K K Subbu <kksubbu.ml(a)gmail.com> wrote: >>>> >>>> Date>>ageOn: aDate >>>> " assert: (self <= aDate) >>>> | age | >>>> >>>> age = aDate year - self year + 1. >>>> aDate monthIndex < self monthIndex ifTrue: [ ^age - 1 ]. >>>> (aDate monthIndex = self monthIndex and: [aDate dayOfMonth < self >>>> dayOfMonth]) ifTrue: [ ^age - 1 ]. >>>> ^age >>>> >>>> HTH .. Subbu >>>> >>>>> On Friday 21 July 2017 05:28 AM, Tim Mackinnon wrote: >>>>> Hi - I just ran a great MobProgramming session with Smalltalk for the >>>>> XProLo group - and there was lots of great feedback and questions, however >>>>> one of them really got me thinkingâ¦ >>>>> We did a little exercise to create a Person class with name, dob - and >>>>> then we TDDâd an age methodâ¦ which seems simple on the surface but it gets >>>>> to an interesting point - what about leap years? How old is someone on those >>>>> years? >>>>> I thought that our plethora of Date/Duration classes might handle this - >>>>> but I couldnât spot something obvious and was wondering if someone had a >>>>> neat answer. >>>>> Essentially if you try: >>>>> age >>>>> ^Date today - self dob >>>>> You get a Duration, >>>>> But there isnât : >>>>> ^(Date today - self dob) asYears >>>>> There is is asDay >>>>> ^(Date today - self dob) asDays >>>>> But then can you really >>>>> ^(Date today - self dob) asDays / 365) truncated >>>>> But what about leap yearsâ¦ so >>>>> ^(Date today - self dob) asDays / 365.25) truncated >>>>> It all feels a bit inelegant and I suspect there is a better Smalltalk >>>>> way that is eluding me? Any suggestions? >>>>> Tim >>>> >>>> >>>> >>> >>> >> >> >

July 21, 2017

Re: [Pharo-users] In Praise of the Very Best Programming Language

by Esteban A. Maringolo

Great! Although it might happen silently, many smalltalkers like me value the "public relations" job you decided to lead on your own. So keep promoting Smalltalk! When something has value in itself, it doesn't need to be sold, only needs awareness in the public. Regards! Esteban A. Maringolo 2017-07-18 1:14 GMT-03:00 horrido <horrido.hobbies(a)gmail.com>: > My farewell article? > https://medium.com/@richardeng/in-praise-of-the-very-best-programming-langu… > <https://medium.com/@richardeng/in-praise-of-the-very-best-programming-langu…> > > > > -- > View this message in context: http://forum.world.st/In-Praise-of-the-Very-Best-Programming-Language-tp495… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >

July 21, 2017

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by Esteban A. Maringolo

Tim, You might consider a full-fledged framework for it like Chalten: https://github.com/ba-st/chalten I don't know how it handles timezones, because the age calculation might get trickier if you consider also the time of birth and you're querying it from a different timezone ;-) Regards! Esteban A. Maringolo 2017-07-21 6:09 GMT-03:00 K K Subbu <kksubbu.ml(a)gmail.com>: > I suppose no one needed it that badly ;-). Age is the difference in years > except when the given date's julian is less than self's julian when it is > less by 1, so the code can be simplified to: > > ^aDate year - self year - > (aDate dayOfYear < self dayOfYear) ifTrue: [ 1 ] ifFalse: [ 0 ]) > > BTW, the code has an off-by-one error. +1 should be dropped in first age > assignment. > > Regards .. Subbu > > > On Friday 21 July 2017 12:55 PM, Tim Mackinnon wrote: >> >> Yes that's a good solution, however I'm really surprised that with the >> plethora of dates, durations, timespans (we are well served with a very rich >> time and date domain) that this isn't already in the image? >> >> It seems very surprising. In fact the group I was working with (other >> language programmers) kept looking and looking for something as they felt >> certain they had overlooked it given all those promising classes. >> >> I'm curious why it's not in there? And would we also expect to find its >> equivalent on a timespan (maybe delegating back to this date method? This >> assumes that timespan can be fixed as it loses precision unexpectedly). >> >> Thanks for the reply. >> >> Tim >> >> >> >> Sent from my iPhone >> >>> On 21 Jul 2017, at 06:41, K K Subbu <kksubbu.ml(a)gmail.com> wrote: >>> >>> Date>>ageOn: aDate >>> " assert: (self <= aDate) >>> | age | >>> >>> age = aDate year - self year + 1. >>> aDate monthIndex < self monthIndex ifTrue: [ ^age - 1 ]. >>> (aDate monthIndex = self monthIndex and: [aDate dayOfMonth < self >>> dayOfMonth]) ifTrue: [ ^age - 1 ]. >>> ^age >>> >>> HTH .. Subbu >>> >>>> On Friday 21 July 2017 05:28 AM, Tim Mackinnon wrote: >>>> Hi - I just ran a great MobProgramming session with Smalltalk for the >>>> XProLo group - and there was lots of great feedback and questions, however >>>> one of them really got me thinkingâ¦ >>>> We did a little exercise to create a Person class with name, dob - and >>>> then we TDDâd an age methodâ¦ which seems simple on the surface but it gets >>>> to an interesting point - what about leap years? How old is someone on those >>>> years? >>>> I thought that our plethora of Date/Duration classes might handle this - >>>> but I couldnât spot something obvious and was wondering if someone had a >>>> neat answer. >>>> Essentially if you try: >>>> age >>>> ^Date today - self dob >>>> You get a Duration, >>>> But there isnât : >>>> ^(Date today - self dob) asYears >>>> There is is asDay >>>> ^(Date today - self dob) asDays >>>> But then can you really >>>> ^(Date today - self dob) asDays / 365) truncated >>>> But what about leap yearsâ¦ so >>>> ^(Date today - self dob) asDays / 365.25) truncated >>>> It all feels a bit inelegant and I suspect there is a better Smalltalk >>>> way that is eluding me? Any suggestions? >>>> Tim >>> >>> >>> >> >> > >

July 21, 2017

Re: [Pharo-users] In Praise of the Very Best Programming Language

by kmo

You've done a great job in promoting smalltalk and pharo. -- View this message in context: http://forum.world.st/In-Praise-of-the-Very-Best-Programming-Language-tp495… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

July 21, 2017

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by K K Subbu

On Friday 21 July 2017 03:01 PM, Tim Mackinnon wrote: > Actually that simplification doesnât work - someone born on 1/Mar/2000 > should be 11 on 1/Mar/2011 and this answers 10 (the previous version did > work). You're right. The simplification does not take into account leap days. Mea culpa. Original code (dropping +1) is readable and simple. Regards .. Subbu > This does make me think its tricky enough to put this in the core - I > may submit it along with the unit tests I borrowed from Stack Overflow > (the shame)â¦ > > Its a good problem though. Thanks for discussing it with me. > > Tim > >> On 21 Jul 2017, at 10:09, K K Subbu <kksubbu.ml(a)gmail.com >> <mailto:kksubbu.ml@gmail.com>> wrote: >> >> ^aDate year - self year - >> (aDate dayOfYear < self dayOfYear) ifTrue: [ 1 ] ifFalse: [ 0 ]) >

July 21, 2017

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by Tim Mackinnon

Actually that simplification doesnât work - someone born on 1/Mar/2000 should be 11 on 1/Mar/2011 and this answers 10 (the previous version did work). This does make me think its tricky enough to put this in the core - I may submit it along with the unit tests I borrowed from Stack Overflow (the shame)â¦ Its a good problem though. Thanks for discussing it with me. Tim > On 21 Jul 2017, at 10:09, K K Subbu <kksubbu.ml(a)gmail.com> wrote: > > ^aDate year - self year - > (aDate dayOfYear < self dayOfYear) ifTrue: [ 1 ] ifFalse: [ 0 ])

July 21, 2017

Critical issues for Dr. Geo on P6

by Hilaire

Hello people, Here are a few critical issues due to bugs or lack of information or feature for porting Dr. Geo to P6. There were others critical issues from P6 but were resolved and will be hopefully integrated, when ? * Minimal Dr. Geo image <https://bugs.launchpad.net/bugs/1705661> * Integration with Playground <https://bugs.launchpad.net/bugs/1701460> * Export bitmap to clipboard <https://bugs.launchpad.net/bugs/1697418><-- it will be really cool to have. <https://bugs.launchpad.net/bugs/1697418> * Universal package for 64 bits <https://bugs.launchpad.net/bugs/1705668> Other issues: https://launchpad.net/drgeo/+milestone/17.09 My initial plane and need is to finish the porting and test by the end of August. Not sure it sounds realistic. Hilaire -- Dr. Geo http://drgeo.eu

July 21, 2017

Re: [Pharo-users] How to calculate someone's age elegantly? Does Duration work?

by K K Subbu

I suppose no one needed it that badly ;-). Age is the difference in years except when the given date's julian is less than self's julian when it is less by 1, so the code can be simplified to: ^aDate year - self year - (aDate dayOfYear < self dayOfYear) ifTrue: [ 1 ] ifFalse: [ 0 ]) BTW, the code has an off-by-one error. +1 should be dropped in first age assignment. Regards .. Subbu On Friday 21 July 2017 12:55 PM, Tim Mackinnon wrote: > Yes that's a good solution, however I'm really surprised that with the plethora of dates, durations, timespans (we are well served with a very rich time and date domain) that this isn't already in the image? > > It seems very surprising. In fact the group I was working with (other language programmers) kept looking and looking for something as they felt certain they had overlooked it given all those promising classes. > > I'm curious why it's not in there? And would we also expect to find its equivalent on a timespan (maybe delegating back to this date method? This assumes that timespan can be fixed as it loses precision unexpectedly). > > Thanks for the reply. > > Tim > > > > Sent from my iPhone > >> On 21 Jul 2017, at 06:41, K K Subbu <kksubbu.ml(a)gmail.com> wrote: >> >> Date>>ageOn: aDate >> " assert: (self <= aDate) >> | age | >> >> age = aDate year - self year + 1. >> aDate monthIndex < self monthIndex ifTrue: [ ^age - 1 ]. >> (aDate monthIndex = self monthIndex and: [aDate dayOfMonth < self dayOfMonth]) ifTrue: [ ^age - 1 ]. >> ^age >> >> HTH .. Subbu >> >>> On Friday 21 July 2017 05:28 AM, Tim Mackinnon wrote: >>> Hi - I just ran a great MobProgramming session with Smalltalk for the XProLo group - and there was lots of great feedback and questions, however one of them really got me thinkingâ¦ >>> We did a little exercise to create a Person class with name, dob - and then we TDDâd an age methodâ¦ which seems simple on the surface but it gets to an interesting point - what about leap years? How old is someone on those years? >>> I thought that our plethora of Date/Duration classes might handle this - but I couldnât spot something obvious and was wondering if someone had a neat answer. >>> Essentially if you try: >>> age >>> ^Date today - self dob >>> You get a Duration, >>> But there isnât : >>> ^(Date today - self dob) asYears >>> There is is asDay >>> ^(Date today - self dob) asDays >>> But then can you really >>> ^(Date today - self dob) asDays / 365) truncated >>> But what about leap yearsâ¦ so >>> ^(Date today - self dob) asDays / 365.25) truncated >>> It all feels a bit inelegant and I suspect there is a better Smalltalk way that is eluding me? Any suggestions? >>> Tim >> >> > >

July 21, 2017