Re: Using 'for each' to modify a container
Hello, Jacque, On 10/11/06 8:14 PM, J. Landman Gay [EMAIL PROTECTED] wrote: Bill Marriott wrote: And I'm *really* concerned about the second part of your report Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. Surely THAT is a definite bug?! Have other people experienced this? Are you able to reproduce it? Is there a bug on it already filed? I do this all the time and I'd have to update a lot of code to fix it. For what it's worth, I do it all the time too and have never had a problem. I think maybe the original poster was just being cautious. I am the original poster, and I will explain a bit more. I have several apps that do some intense data parsing, error checks, and reformatting. At some point during the development a few months ago I was trying to chase a set of bugs in a handler that were very elusive. My standard repeat form evolved to: repeat for each line LNN in varList put item 1 to 2 of LNN cr after newVarList end repeat delete char -1 of newVarList and, like you, reused my choice of LNN. Cool beans. However...in one long handler... Using Variable Watcher and some test variables, I saw 'LNN' change the way you would expect, then later, strangely, it held some garbage characters, and thus the bug(s). The failure was not always the same, but it did fail before the end of the process. By not reusing LNN each time, the problem has not returned. My current system is to use LNN1, LNN2, LNN3, etc. The reason I use all caps is to remind me not to change the variable, but rather recast ( eg. get LNN) so I could change the value. You are right about 'just being cautious'. I have too much to accomplish to go through the 'strange debug' again. Jim Ault Las Vegas ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
Clearly, it shouldn't be necessary, but I wonder if putting empty into LNN or delete variable LNN after each loop has finished would cure that? Best, Mark On 12 Oct 2006, at 07:51, Jim Ault wrote: Hello, Jacque, On 10/11/06 8:14 PM, J. Landman Gay [EMAIL PROTECTED] wrote: Bill Marriott wrote: And I'm *really* concerned about the second part of your report Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. Surely THAT is a definite bug?! Have other people experienced this? Are you able to reproduce it? Is there a bug on it already filed? I do this all the time and I'd have to update a lot of code to fix it. For what it's worth, I do it all the time too and have never had a problem. I think maybe the original poster was just being cautious. I am the original poster, and I will explain a bit more. I have several apps that do some intense data parsing, error checks, and reformatting. At some point during the development a few months ago I was trying to chase a set of bugs in a handler that were very elusive. My standard repeat form evolved to: repeat for each line LNN in varList put item 1 to 2 of LNN cr after newVarList end repeat delete char -1 of newVarList and, like you, reused my choice of LNN. Cool beans. However...in one long handler... Using Variable Watcher and some test variables, I saw 'LNN' change the way you would expect, then later, strangely, it held some garbage characters, and thus the bug(s). The failure was not always the same, but it did fail before the end of the process. By not reusing LNN each time, the problem has not returned. My current system is to use LNN1, LNN2, LNN3, etc. The reason I use all caps is to remind me not to change the variable, but rather recast ( eg. get LNN) so I could change the value. You are right about 'just being cautious'. I have too much to accomplish to go through the 'strange debug' again. Jim Ault Las Vegas ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
Using Variable Watcher and some test variables, I saw 'LNN' change the way you would expect, then later, strangely, it held some garbage characters, and thus the bug(s). The failure was not always the same, but it did fail before the end of the process. By not reusing LNN each time, the problem has not returned. FWIW, I ran into a similar issue some time ago: garbage characters randomly appearing in a variable. Took me weeks of messing around with complex code since I couldn't get simple tests to fail. Eventually I determined the problem was contrived object references. I was manually creating object references like btn 1 of stack coolstack which for some reason was intermittently failing and being stored as garbage. Once I started referencing objects using their long IDs, the problem disappeared. Chalk this up as another ...might save someone else a few headaches Regards, Scott Rossi Creative Director Tactile Media, Multimedia Design - E: [EMAIL PROTECTED] W: http://www.tactilemedia.com ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
The first part though, about not changing the contents of a loop variable, does give unexpected results though I hardly ever get an actual script error. Usually I just get scrambled variables. -- Jacqueline Landman Gay | [EMAIL PROTECTED] HyperActive Software | http://www.hyperactivesw.com Strange. I do it all the time and never seen a problem. Notably all such loops in my programs are really short, no more than a few lines. May be I am just lucky that I do not trigger the condition that scrambles the content but it might be time to change my habits :) Robert Brenstein ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
On Oct 12, 2006, at 12:03 AM, Mark Smith wrote: Clearly, it shouldn't be necessary, but I wonder if putting empty into LNN or delete variable LNN after each loop has finished would cure that? Putting empty into the labelVariable in each repeat loop solves some problems so I would imagine it would in the above as well. I've done this before: repeat for each line theLine in theData split theLine by ; AND : -- do something fancy put empty into theLine end repeat Without the line put empty into theLine the code doesn't always work correctly. With the line it does. Of course, according to the docs I was being bad and should change my behavior. -- Trevor DeVore Blue Mango Learning Systems - www.bluemangolearning.com [EMAIL PROTECTED] ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
I have experienced no corruption of data, but I certainly have had unexpected behavior. Given: put 1 into mcnt repeat for each line tline in mlist put empty into word 1 of tline put tline into line mcnt of mlist put mcnt + 1 into mcnt end repeat As each iteration of the repeat loop progresses I find the data I get in tline is shifted to the right by the length of the deleted data. I can only think an index is created at the start of the loop which points to a memory location, and since the data is shifting while the pointer does not, you must not change the contents of mlist until the loop is finished. So I learned when using this form to either store the contents of mlist in a temporary variable and modify that, or build a temporary variable as I go until the loop is complete. Then I put the contents of that variable into mlist if that's what I want. I have had no problems changing the contents of tline. Bob Sneidar IT Manager Logos Management Calvary Chapel CM On Oct 11, 2006, at 5:45 AM, Mark Powell wrote: I want to use the 'for each' form of the repeat loop, but don't know how to use it to modify data within a container. For example: repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine) into item -2 of thisLine --how do I get the change back into vContainer? end repeat Thanks! Mark Powell mark_powell (at symbol) symantec.com ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
Robert Sneidar wrote: put 1 into mcnt repeat for each line tline in mlist put empty into word 1 of tline put tline into line mcnt of mlist put mcnt + 1 into mcnt end repeat FWIW, doing the data collection with the form put...into line... loses much of the performance value of using repeat for each, as it requires the engine to crawl through mlist looking for mcnt number of CRs each time through the loop. To counter this, some years ago Scott Raney optimized the put...after form, so you could have a second variable as a collector for things you gather during the iteration, and would probably see a snappy performance boost: put empty into tNuList repeat for each line tline in mlist put empty into word 1 of tline put tline cr after tNuList end repeat This practice of collecting from one source and concatenating to a different destination also takes care of the anomalies you noted when attempting to modify the source container within a repeat for each loop. -- Richard Gaskin Fourth World Media Corporation ___ [EMAIL PROTECTED] http://www.FourthWorld.com ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Using 'for each' to modify a container
I want to use the 'for each' form of the repeat loop, but don't know how to use it to modify data within a container. For example: repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine) into item -2 of thisLine --how do I get the change back into vContainer? end repeat Thanks! Mark Powell mark_powell (at symbol) symantec.com ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
hi Mark, try this: repeat for each line thisLine in vContainer put thisLine into tLine put doSomeFunction(item -2 of thisLine) into item -2 of tLine put tLine cr after tContainer end repeat delete char -1 of tContainer put tContainer into vContainer Hope that helps, malte ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
You shouldn't try to change the tires while the car is moving, and you shouldn't try to modify the entity being used as the basis of a repeat loop. For example, if you were to say repeat with i = 1 to 20 end repeat you shouldn't try to modify i within the loop. If you say repeat for each line theLine in myVariable end repeat you shouldn't try to modify myVariable within the loop. There are probably many possibilities for your solution, but I would probably do it this way: put empty into newContainer repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine) into item -2 of thisLine put thisLine return after newContainer end repeat put char 1 to -2 of newContainer into vContainer Mark Powell wrote: I want to use the 'for each' form of the repeat loop, but don't know how to use it to modify data within a container. For example: repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine) into item -2 of thisLine --how do I get the change back into vContainer? end repeat ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
On 10/11/06 6:34 AM, Bill Marriott [EMAIL PROTECTED] wrote: You shouldn't try to change the tires while the car is moving, and you shouldn't try to modify the entity being used as the basis of a repeat loop. For example, if you were to say repeat with i = 1 to 20 end repeat you shouldn't try to modify i within the loop. If you say repeat for each line theLine in myVariable end repeat you shouldn't try to modify myVariable within the loop. There are probably many possibilities for your solution, but I would probably do it this way: put empty into newContainer repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine) into item -2 of thisLine put thisLine return after newContainer end repeat put char 1 to -2 of newContainer into vContainer Actually, I try to avoid changing the value returned by the 'for each' --original version put empty into newContainer repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine) into item -2 of thisLine put thisLine return after newContainer end repeat put char 1 to -2 of newContainer into vContainer --my preference is put empty into newContainer repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine)cr after newContainer end repeat put char 1 to -2 of newContainer into vContainer I think the reason that 'for each' is so fast is that it scans the vContainer memory space, returns those characters, and is not meant to be modified. My experience is that it is unpredictable to rely on the changed value of 'thisLine' Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. Jim Ault Las Vegas ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
Hi Jim, I think the reason that 'for each' is so fast is that it scans the vContainer memory space, returns those characters, and is not meant to be modified. My experience is that it is unpredictable to rely on the changed value of 'thisLine' Wow, this is very interesting to me. I just checked the documentation (2.6.1) on the for each chunkType labelVariable for of repeat, and was astonished to find: Important! You cannot change the labelVariable in a statement inside the loop. Doing so will cause a script error. You can change the content of the container, but doing so will probably produce unexpected results. Ya learn something new every day! Sounds kind of cheesy to me, though. Why wouldn't it be identical to repeat with i = 1 to the number of chunkType in theContainer put chunkType i of theContainer into labelVariable -- do stuff end repeat Your explanation is plausible, but if it is so then why permit (You can change...) changing the contents of the container itself within the loop? That would seem to cause an even bigger problem. BTW, I set up a button with the following script: on mouseUp put empty into newContainer repeat for each line thisLine in fld 1 put thisline *** into thisLine put thisLine return after newContainer end repeat put char 1 to -2 of newContainer into fld 1 end mouseUp Which not only didn't generate a script error but worked perfectly as expected. Is the bug in the documentation, or that it doesn't generate a script error, or that for each doesn't let you modify the labelVariable? And I'm *really* concerned about the second part of your report Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. Surely THAT is a definite bug?! Have other people experienced this? Are you able to reproduce it? Is there a bug on it already filed? I do this all the time and I'd have to update a lot of code to fix it. This would suggest to me that maybe I shouldn't use i more than once in a handler as the control variable for a repeat as well (something I always do, unless nesting the loops of course). I won't even get into the idea of declaring the labelVariable as a global! --my preference is put empty into newContainer repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine)cr after newContainer end repeat put char 1 to -2 of newContainer into vContainer ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
On 10/11/06 3:05 PM, Bill Marriott [EMAIL PROTECTED] wrote: Hi Jim, I think the reason that 'for each' is so fast is that it scans the vContainer memory space, returns those characters, and is not meant to be modified. My experience is that it is unpredictable to rely on the changed value of 'thisLine' Wow, this is very interesting to me. I just checked the documentation (2.6.1) on the for each chunkType labelVariable for of repeat, and was astonished to find: Important! You cannot change the labelVariable in a statement inside the loop. Doing so will cause a script error. You can change the content of the container, but doing so will probably produce unexpected results. (disclaimer.. I do not have assembler programming, or other low-level experience, so what follows in an amateur discussion) I believe this stems from the way memory registers are managed. The very tiny bit of C and Pascal programming I read meant I had to first learn how to manage anything I created, finally releasing it back to the operating system. The penalty was mucho errors and unexpected results. My guess is that Rev is allowing speed in cases where they do not have to munger variables in memory, therefore you cannot reliably 'redefine' them on the fly. A loop counter may be an offset index that is pre-set when the loop starts, thus very fast, but not to be changed during execution. Kinda like re-indexing a database. I am ready for those who know the real story to fire away :-) Ya learn something new every day! Sounds kind of cheesy to me, though. Why wouldn't it be identical to repeat with i = 1 to the number of chunkType in theContainer put chunkType i of theContainer into labelVariable -- do stuff end repeat The 'to the number of' useage is much, much slower, thus not identical Your explanation is plausible, but if it is so then why permit (You can change...) changing the contents of the container itself within the loop? That would seem to cause an even bigger problem. BTW, I set up a button with the following script: on mouseUp put empty into newContainer repeat for each line thisLine in fld 1 put thisline *** into thisLine put thisLine return after newContainer end repeat put char 1 to -2 of newContainer into fld 1 end mouseUp Which not only didn't generate a script error but worked perfectly as expected. Is the bug in the documentation, or that it doesn't generate a script error, or that for each doesn't let you modify the labelVariable? The error probably depends on what other operations are being done in the memory stack of Rev. Here 'memory stack' is the area of computer memory registers the system reserves for Rev to use. If nothing requires Rev to 'move' memory locations, then your labelVariable will be in the same location the next time you want to access it. Its like the coffee cup on your desk. You reach for it without looking, and all is well, unless someone pushed it closer to you when you were not looking. And I'm *really* concerned about the second part of your report Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. Surely THAT is a definite bug?! Have other people experienced this? Are you able to reproduce it? Is there a bug on it already filed? I do this all the time and I'd have to update a lot of code to fix it. This would suggest to me that maybe I shouldn't use i more than once in a handler as the control variable for a repeat as well (something I always do, unless nesting the loops of course). I won't even get into the idea of declaring the labelVariable as a global! All I can say is that you are getting a tradeoff... memory registers + speed vs controlled variables and definitions --my preference is put empty into newContainer repeat for each line thisLine in vContainer put doSomeFunction(item -2 of thisLine)cr after newContainer end repeat put char 1 to -2 of newContainer into vContainer ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
On 10/11/06 5:05 PM, Bill Marriott [EMAIL PROTECTED] wrote: Wow, this is very interesting to me. I just checked the documentation (2.6.1) on the for each chunkType labelVariable for of repeat, and was astonished to find: Important! You cannot change the labelVariable in a statement inside the loop. Doing so will cause a script error. You can change the content of the container, but doing so will probably produce unexpected results. Ya learn something new every day! Sounds kind of cheesy to me, though. Why wouldn't it be identical to repeat with i = 1 to the number of chunkType in theContainer put chunkType i of theContainer into labelVariable -- do stuff end repeat Because in the example you cite above, every time through the loop, Rev has to count the number of chunkType until it reaches the desired location. Take a look at this Script C from this tip from a while back for more info: Increasing Script Performance, Part I http://www.sonsothunder.com/devres/revolution/tips/scrp005.htm in fact the other tips in this series are equally important: Increasing Script Performance, Part II http://www.sonsothunder.com/devres/revolution/tips/scrp006.htm Increasing Script Performance, Part III http://www.sonsothunder.com/devres/revolution/tips/scrp007.htm Your explanation is plausible, but if it is so then why permit (You can change...) changing the contents of the container itself within the loop? That would seem to cause an even bigger problem. BTW, I set up a button with the following script: on mouseUp put empty into newContainer repeat for each line thisLine in fld 1 put thisline *** into thisLine put thisLine return after newContainer end repeat put char 1 to -2 of newContainer into fld 1 end mouseUp Which not only didn't generate a script error but worked perfectly as expected. Is the bug in the documentation, or that it doesn't generate a script error, or that for each doesn't let you modify the labelVariable? It's not the loop variable that is problematic to change, it's the container. So in this: repeat for each line tLine in tData you can manipulate tLine to your hearts content, but not tData. tData has already been examined, parsed, and put into memory in known places so iteration through the loop can go lightning fast... if you attempt to change tData you throw a wrench in the works. And I'm *really* concerned about the second part of your report Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. I personally haven't ever encountered this. I have always been able to reuse the loop variable without problem... Ken Ray Sons of Thunder Software Web site: http://www.sonsothunder.com/ Email: [EMAIL PROTECTED] ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
Bill Marriott wrote: And I'm *really* concerned about the second part of your report Further, I don't reuse the name 'thisLine' in the next instance of a repeat for each loop in the *same handler*, but change the name to avoid conflict, such as 'thisline', 'thisline1', 'thisLine2'. Again, unpredictable results occasionally. Surely THAT is a definite bug?! Have other people experienced this? Are you able to reproduce it? Is there a bug on it already filed? I do this all the time and I'd have to update a lot of code to fix it. For what it's worth, I do it all the time too and have never had a problem. I think maybe the original poster was just being cautious. The first part though, about not changing the contents of a loop variable, does give unexpected results though I hardly ever get an actual script error. Usually I just get scrambled variables. -- Jacqueline Landman Gay | [EMAIL PROTECTED] HyperActive Software | http://www.hyperactivesw.com ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
you can manipulate tLine to your hearts content, but not tData. tData has already been examined, parsed, and put into memory in known places so iteration through the loop can go lightning fast... if you attempt to change tData you throw a wrench in the works. But Ken, that's exactly what the documentation says is NOT to be done (and should generate a script error). My first post assumed what you said (ok to manipulate tLine, not to manipulate tData), but it seems the reality is opposite. Weird, huh? :) ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
On 10/11/06 10:21 PM, Bill Marriott [EMAIL PROTECTED] wrote: you can manipulate tLine to your hearts content, but not tData. tData has already been examined, parsed, and put into memory in known places so iteration through the loop can go lightning fast... if you attempt to change tData you throw a wrench in the works. But Ken, that's exactly what the documentation says is NOT to be done (and should generate a script error). Wow... haven't gotten any script errors or any scrambled data... oh well, I guess I'm just lucky... My first post assumed what you said (ok to manipulate tLine, not to manipulate tData), but it seems the reality is opposite. Weird, huh? :) Actually when I reread the statement: Important! You cannot change the labelVariable in a statement inside the loop. Doing so will cause a script error. You can change the content of the container, but doing so will probably produce unexpected results. It sounds like you shouldn't maniuplate either... Ken Ray Sons of Thunder Software Web site: http://www.sonsothunder.com/ Email: [EMAIL PROTECTED] ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
Re: Using 'for each' to modify a container
Yes! I wouldn't mess around behind rev's back like that- especially with 'binaries'. sqb It sounds like you shouldn't maniuplate either... Ken Ray -- stephen barncard s a n f r a n c i s c o - - - - - - - - - - - - ___ use-revolution mailing list use-revolution@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-revolution
