Re: Unexpected comparison behavior change in 4.5.1
This WebDNA talk-list message is from 2003
It keeps the original formatting.
numero = 48769
interpreted = N
texte = Hi Charles,bob contains an empty string just exactly as much as an empty string contains an empty string. I thought Brian's explanation was good. I'm not sure what you didn't understand about it.I also agree with Brian that of course the behavior should not be changed without good reason and without notification in an upgrade. My understanding from Phil's reply is that this was not an intentional change, and they'll look into it. While in an ideal world software would be bug-free, and software updates would not contain inadvertent changes in behavior and new bugs, I haven't seen a software update yet in my 20 years programming that didn't have some of those. Even the biggest companies don't test adequately--because no one knows how to test adequately. All of us release software to our clients with bugs, and fix them when they're found. I'm hoping that Smith Micro will look into it, and if the behavior was inadvertently changed, they'll change it back in 4.5.2. This is tremendously inconvenient for someone in Brian's situation, of course. He might do best to rewrite his code to not use this particular algorithm.VelmaAt 12:26 PM 3/18/2003, you wrote: >explain. > >- ck > >On Tuesday, March 18, 2003, at 12:25 PM, Velma Kahn wrote: > >>Brian is quite correct, as far as I can see. >>Velma >> >> >>At 12:21 PM 3/18/2003, you wrote: >>>Brian, >>> >>>That is not correct. >>> >>>bob is a string consisting of the letters 'bob' it DOES contain 'b' >>>(which is what the ^ means to WebDNA) it does not contain '' which is >>>what [showif bob^] means as well as [if bob^]. Both these statements >>>are FALSE. >>> >>>Someone correct me if I'm wrong please :) >>> >>>- Charles >>> >>> >>>On Tuesday, March 18, 2003, at 10:29 AM, Brian Fries wrote: >>> >>>>Your description is inconclusive. If I was checking for b, then, to >>>>paraphrase you: >>>> >>>>What your comparison is saying IF bob contains b then true. bob >>>>contains bob therefore is false in both cases. >>>> >>>>This is not a test for equality, and bob contains NOTHING an infinite >>>>number of times. >>>> >>>>Again, I'm not saying that one result is better than the other - >>>>logically it's an inconclusive test. What I am saying is that, since >>>>it's inconclusive, it SHOULD NOT HAVE BEEN CHANGED WITHOUT GOOD REASON >>>>AND WITHOUT NOTIFYING DEVELOPERS THAT THEIR CODE MIGHT BREAK. >>>> >>>>SMSI: Comments? Scott? Please? >>>> >>>>- brian >>>> >>>>On Tuesday, March 18, 2003, at 12:47 AM, Charles Kline wrote: >>>> >>>>>What your comparison is saying IF bob contains NOTHING then true. bob >>>>>contains bob therefore is false in both cases. >>>>> >>>>>On Tuesday, March 18, 2003, at 01:56 AM, Brian Fries wrote: >>>>> >>>>>>On Monday, March 17, 2003, at 10:38 PM, Charles Kline wrote: >>>>>> >>>>>>> >>>>>>>On Tuesday, March 18, 2003, at 01:32 AM, Brian Fries wrote: >>>>>>> >>>>>>>>[showif bob^] >>>>>>>> >>>>>>>>or >>>>>>>> >>>>>>>>[if bob^] >>>>>>>> >>>>>>>> >>>>>>>>In my tests, these evaluate to true under 4.5.0 and earlier, and >>>>>>>>to false under 4.5.1. Clearly URL is not the issue here. >>>>>>>[showif bob^] should evaluate to 'false' so it seems the bug was in >>>>>>>4.5.0 >>>>>> >>>>>>And WHY should [showif bob^] evaluate false? I don't see anything in >>>>>>the empty string that isn't also in bob, therefore I - and every >>>>>>version of WebDNA prior to 4.5.1 - would expect it to evaluate to > true. >>>>>> >>>>>>> >>>>>>>[if bob^] should evaluate to 'false' as well. >>>>>> >>>>>>Again, why is false any better than true for this? If WebDNA were >>>>>>being written from scratch, then it would be the right time to make a >>>>>>choice on this. But, since it's worked the same way since I began >>>>>>using the product in 1997, I think its a little late to make this change. >>>>>> >>>>>>I'm not really here to debate which way it SHOULD resolve the >>>>>>comparison, I'm only here to point out that it broke my code - which >>>>>>was fully tested and had been working fine for years. >>>>>> >>>>>>>It was always my understanding that when using [if] to compare >>>>>>>strings, they needed to be in quotes. Was in the docs. as that from >>>>>>>the beginning. >>>>>> >>>>>>Relevance? What quotes do you see missing from my example? >>>>>> >>>>>>- brian >>>> >>>> >>>>------------------------------------------------------------- >>>>This message is sent to you because you are subscribed to >>>> the mailing list
. >>>>To unsubscribe, E-mail to: >>>>To switch to the DIGEST mode, E-mail to >>>> >>>>Web Archive of this list is at: http://webdna.smithmicro.com/ >>> >>> >>>------------------------------------------------------------- >>>This message is sent to you because you are subscribed to >>> the mailing list . >>>To unsubscribe, E-mail to: >>>To switch to the DIGEST mode, E-mail to >>> >>>Web Archive of this list is at: http://webdna.smithmicro.com/ >> >>---------------------------------------- >>Velma Kahn >>Glory Day Software Company >>200 Tanager Ln NW, Floyd, Virginia 24091, U.S.A. >>phone: 540-745-6469 * fax: 651-321-4884 >>email: vkahn@glorydaysoftware.com >>http://www.glorydaysoftware.com >>http://www.communitymade.com >>http://www.floydcrafts.com >> >> >>------------------------------------------------------------- >>This message is sent to you because you are subscribed to >> the mailing list . >>To unsubscribe, E-mail to: >>To switch to the DIGEST mode, E-mail to >> >>Web Archive of this list is at: http://webdna.smithmicro.com/ > > >------------------------------------------------------------- >This message is sent to you because you are subscribed to > the mailing list . >To unsubscribe, E-mail to: >To switch to the DIGEST mode, E-mail to > >Web Archive of this list is at: http://webdna.smithmicro.com/---------------------------------------- Velma Kahn Glory Day Software Company 200 Tanager Ln NW, Floyd, Virginia 24091, U.S.A. phone: 540-745-6469 * fax: 651-321-4884 email: vkahn@glorydaysoftware.com http://www.glorydaysoftware.com http://www.communitymade.com http://www.floydcrafts.com ------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://webdna.smithmicro.com/
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Hi Charles,bob contains an empty string just exactly as much as an empty string contains an empty string. I thought Brian's explanation was good. I'm not sure what you didn't understand about it.I also agree with Brian that of course the behavior should not be changed without good reason and without notification in an upgrade. My understanding from Phil's reply is that this was not an intentional change, and they'll look into it. While in an ideal world software would be bug-free, and software updates would not contain inadvertent changes in behavior and new bugs, I haven't seen a software update yet in my 20 years programming that didn't have some of those. Even the biggest companies don't test adequately--because no one knows how to test adequately. All of us release software to our clients with bugs, and fix them when they're found. I'm hoping that Smith Micro will look into it, and if the behavior was inadvertently changed, they'll change it back in 4.5.2. This is tremendously inconvenient for someone in Brian's situation, of course. He might do best to rewrite his code to not use this particular algorithm.VelmaAt 12:26 PM 3/18/2003, you wrote: >explain. > >- ck > >On Tuesday, March 18, 2003, at 12:25 PM, Velma Kahn wrote: > >>Brian is quite correct, as far as I can see. >>Velma >> >> >>At 12:21 PM 3/18/2003, you wrote: >>>Brian, >>> >>>That is not correct. >>> >>>bob is a string consisting of the letters 'bob' it DOES contain 'b' >>>(which is what the ^ means to WebDNA) it does not contain '' which is >>>what [showif bob^] means as well as [if bob^]. Both these statements >>>are FALSE. >>> >>>Someone correct me if I'm wrong please :) >>> >>>- Charles >>> >>> >>>On Tuesday, March 18, 2003, at 10:29 AM, Brian Fries wrote: >>> >>>>Your description is inconclusive. If I was checking for b, then, to >>>>paraphrase you: >>>> >>>>What your comparison is saying IF bob contains b then true. bob >>>>contains bob therefore is false in both cases. >>>> >>>>This is not a test for equality, and bob contains NOTHING an infinite >>>>number of times. >>>> >>>>Again, I'm not saying that one result is better than the other - >>>>logically it's an inconclusive test. What I am saying is that, since >>>>it's inconclusive, it SHOULD NOT HAVE BEEN CHANGED WITHOUT GOOD REASON >>>>AND WITHOUT NOTIFYING DEVELOPERS THAT THEIR CODE MIGHT BREAK. >>>> >>>>SMSI: Comments? Scott? Please? >>>> >>>>- brian >>>> >>>>On Tuesday, March 18, 2003, at 12:47 AM, Charles Kline wrote: >>>> >>>>>What your comparison is saying IF bob contains NOTHING then true. bob >>>>>contains bob therefore is false in both cases. >>>>> >>>>>On Tuesday, March 18, 2003, at 01:56 AM, Brian Fries wrote: >>>>> >>>>>>On Monday, March 17, 2003, at 10:38 PM, Charles Kline wrote: >>>>>> >>>>>>> >>>>>>>On Tuesday, March 18, 2003, at 01:32 AM, Brian Fries wrote: >>>>>>> >>>>>>>>[showif bob^] >>>>>>>> >>>>>>>>or >>>>>>>> >>>>>>>>[if bob^] >>>>>>>> >>>>>>>> >>>>>>>>In my tests, these evaluate to true under 4.5.0 and earlier, and >>>>>>>>to false under 4.5.1. Clearly URL is not the issue here. >>>>>>>[showif bob^] should evaluate to 'false' so it seems the bug was in >>>>>>>4.5.0 >>>>>> >>>>>>And WHY should [showif bob^] evaluate false? I don't see anything in >>>>>>the empty string that isn't also in bob, therefore I - and every >>>>>>version of WebDNA prior to 4.5.1 - would expect it to evaluate to > true. >>>>>> >>>>>>> >>>>>>>[if bob^] should evaluate to 'false' as well. >>>>>> >>>>>>Again, why is false any better than true for this? If WebDNA were >>>>>>being written from scratch, then it would be the right time to make a >>>>>>choice on this. But, since it's worked the same way since I began >>>>>>using the product in 1997, I think its a little late to make this change. >>>>>> >>>>>>I'm not really here to debate which way it SHOULD resolve the >>>>>>comparison, I'm only here to point out that it broke my code - which >>>>>>was fully tested and had been working fine for years. >>>>>> >>>>>>>It was always my understanding that when using [if] to compare >>>>>>>strings, they needed to be in quotes. Was in the docs. as that from >>>>>>>the beginning. >>>>>> >>>>>>Relevance? What quotes do you see missing from my example? >>>>>> >>>>>>- brian >>>> >>>> >>>>------------------------------------------------------------- >>>>This message is sent to you because you are subscribed to >>>> the mailing list . >>>>To unsubscribe, E-mail to: >>>>To switch to the DIGEST mode, E-mail to >>>> >>>>Web Archive of this list is at: http://webdna.smithmicro.com/ >>> >>> >>>------------------------------------------------------------- >>>This message is sent to you because you are subscribed to >>> the mailing list . >>>To unsubscribe, E-mail to: >>>To switch to the DIGEST mode, E-mail to >>> >>>Web Archive of this list is at: http://webdna.smithmicro.com/ >> >>---------------------------------------- >>Velma Kahn >>Glory Day Software Company >>200 Tanager Ln NW, Floyd, Virginia 24091, U.S.A. >>phone: 540-745-6469 * fax: 651-321-4884 >>email: vkahn@glorydaysoftware.com >>http://www.glorydaysoftware.com >>http://www.communitymade.com >>http://www.floydcrafts.com >> >> >>------------------------------------------------------------- >>This message is sent to you because you are subscribed to >> the mailing list . >>To unsubscribe, E-mail to: >>To switch to the DIGEST mode, E-mail to >> >>Web Archive of this list is at: http://webdna.smithmicro.com/ > > >------------------------------------------------------------- >This message is sent to you because you are subscribed to > the mailing list . >To unsubscribe, E-mail to: >To switch to the DIGEST mode, E-mail to > >Web Archive of this list is at: http://webdna.smithmicro.com/---------------------------------------- Velma Kahn Glory Day Software Company 200 Tanager Ln NW, Floyd, Virginia 24091, U.S.A. phone: 540-745-6469 * fax: 651-321-4884 email: vkahn@glorydaysoftware.com http://www.glorydaysoftware.com http://www.communitymade.com http://www.floydcrafts.com ------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://webdna.smithmicro.com/
Velma Kahn
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