Re: [Lazarus] WinINet STDCALL callback crash
On 03/04/2013 12:45 AM, matt...@accordancebible.com wrote: Ludo, Thank you very much for your most informative posting. I have spent the week trying to implement the msdn examples in pure Pascal and in Pascal-DLL hybrids. Success in non-threaded asynchrosity eludes me though. Your example (http://www.lazarus.freepascal.org/index.php?topic=18506.15#msg105226) using URLMON's URLDownloadToFile works perfectly. However, the example is synchronous whilst we need asynchronous. Research indicates that URLOpenPullStream is the more relevant function in our case (because we download asynchronously to both memory streams and files, depending on what flags the user sets and can track the progress of the download). The problem is that URLOpenPullStream and URLDownloadToFile (which I am using as an intermediate coding step) both require a variable of a type that implements the IBindStatusCallback interface, which in turn requires declaration of the IBinding interface. I have tried doing so without success; I share my code below. Is there a way to access the UrlMon.dll's definition of IBindStatus and IBinding so that these interfaces are available within Lazarus? Currently, the only option I see is to define these interfaces myself. Alternatively, is there an example of a Lazarus definition of these interfaces? FYI, after the program segfaults, the assembler window points within urlmon!ZonesReInit Thank you for any help you might provide. This is definitely the most difficult route to async you are trying to walk;) Delphi has an unit to support urlmon that defines all these interfaces but I still have to see a stable and reliable piece of code that manages to use URLOpenPullStream. Also quite some knowledge on COM interfaces is need to try to get that working. For example QueryInterface := E_NOTIMPL; is a no go in interfaces. Why don't you use a standard async library such as lNet (http://wiki.freepascal.org/lNet, http://lnet.wordpress.com/)? It has a lazarus package that will install amongst others the TLHTTPClientComponent that has already the necessary events. The library comes with a httpclienttest example application that show you how to use the component. There is also Indy (http://wiki.freepascal.org/Indy_with_Lazarus) which is async although that library is much bigger and compatibility with lazarus is not that good as well as its portability to other platforms. Ludo -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
[Lazarus] some number manipulation
Hi all, I have a series of results, for each day of the month I have 10 numbers ranging from 1 to 20. i.e. Day11,3,4,5,7,9,12,16,17,20 Day23,4,5,6,8,9,15,17,18,19 etc. Question 1 how can I find the number of 1's 2's 3's 4's etc. for the whole month series? Question 2 How can I test for 3 or more consecutive numbers in each day? Hope this is clear, any guidance will be most appreciated. Paul -- ---This message has been sent using Thunderbird on kubuntu--- -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] some number manipulation
On 09/03/13 11:12, appjaws wrote: Hi all, I have a series of results, for each day of the month I have 10 numbers ranging from 1 to 20. i.e. Day11,3,4,5,7,9,12,16,17,20 Day23,4,5,6,8,9,15,17,18,19 etc. Question 1 how can I find the number of 1's 2's 3's 4's etc. for the whole month series? Question 2 How can I test for 3 or more consecutive numbers in each day? Q1 for such a small dataset a brute force approach of iterating over all values and counting each occurrence of 1, 2, 3 etc. in 20 distinct counters seems best. Q2 Your data is ordered by value, so a function along these lines ought to work: type TNumber = 1..20; TDayData = array[1..10] of TNumber; function ThreeOrMoreConsecutiveNos(dd: TDayData): boolean; var i: integer=1; begin Result:= False; while i =8 do begin if ( dd[i]=Pred(dd[i+1]) ) and ( dd[i+1]=Pred(dd[i+2]) ) then Exit(True); Inc(i); end; end; -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] some number manipulation
On 09/03/13 12:11, Howard Page-Clark wrote: On 09/03/13 11:12, appjaws wrote: Hi all, I have a series of results, for each day of the month I have 10 numbers ranging from 1 to 20. i.e. Day11,3,4,5,7,9,12,16,17,20 Day23,4,5,6,8,9,15,17,18,19 etc. Question 1 how can I find the number of 1's 2's 3's 4's etc. for the whole month series? Question 2 How can I test for 3 or more consecutive numbers in each day? Q1 for such a small dataset a brute force approach of iterating over all values and counting each occurrence of 1, 2, 3 etc. in 20 distinct counters seems best. Q2 Your data is ordered by value, so a function along these lines ought to work: type TNumber = 1..20; TDayData = array[1..10] of TNumber; function ThreeOrMoreConsecutiveNos(dd: TDayData): boolean; var i: integer=1; begin Result:= False; while i =8 do begin if ( dd[i]=Pred(dd[i+1]) ) and ( dd[i+1]=Pred(dd[i+2]) ) then Exit(True); Inc(i); end; end; Thank you Howard, I just realised that I need to sort the numbers because they are not like my example above. So where and how would I sort the array for each Day and then call ThreeOrMore? I'm still learning and really appreciate your help Paul -- ---This message has been sent using Thunderbird on kubuntu--- -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] some number manipulation
On 09/03/13 3:06, appjaws wrote: I have a series of results, for each day of the month I have 10 numbers ranging from 1 to 20. i.e. Day11,3,4,5,7,9,12,16,17,20 Day23,4,5,6,8,9,15,17,18,19 ... I just realised that I need to sort the numbers because they are not like my example above. So where and how would I sort the array for each Day and then call ThreeOrMore? If you have any programming books you'll almost certainly find they include a chapter on sorting algorithms (bubble sort, quicksort etc.). One FPC/Lazarus tutorial implementation is at http://www.pp4s.co.uk/main/tu-ss-sort-quick-demo1a.html and Lazarus also has several integer quicksort implementations in its own code such as at ...\lazarus\lcl\grids.pas, line 2850 Howard -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] some number manipulation
I would create a matrix A[i,j] with i = 1,2,3,...31 (31 rows) and j=1,2,3,...20 (20 columns). Initialize the matrix to all zeroes. Then for each day of the month, if the number k occurs in day j, then set A[j,k] := 1. At the end of the month, the sum of the elements in row k will tell you how many times k occurred during the month. Then scan each row of the matrix looking for three or more consecutive 1's (left as an exercise :-) On 3/9/2013 10:00 AM, Howard Page-Clark wrote: On 09/03/13 3:06, appjaws wrote: I have a series of results, for each day of the month I have 10 numbers ranging from 1 to 20. i.e. Day11,3,4,5,7,9,12,16,17,20 Day23,4,5,6,8,9,15,17,18,19 ... I just realised that I need to sort the numbers because they are not like my example above. So where and how would I sort the array for each Day and then call ThreeOrMore? If you have any programming books you'll almost certainly find they include a chapter on sorting algorithms (bubble sort, quicksort etc.). One FPC/Lazarus tutorial implementation is at http://www.pp4s.co.uk/main/tu-ss-sort-quick-demo1a.html and Lazarus also has several integer quicksort implementations in its own code such as at ...\lazarus\lcl\grids.pas, line 2850 Howard -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
