Re: [fpc-pascal] Re: Why this evaluates on if wrong ? (GMP)
On Tuesday 30 October 2007 17:31, Inga Petuhhov wrote: A copy-paste from Python Shell: a = 1 a 1 a = a + 0.4 a 1.3999 a = a - 0.4 a 0.99989 a == 1 False Or a bit more simple (and for some maybe even more surprising): 1.0 == 0.4 - 0.4 + 1.0 True 1.0 == 1.0 + 0.4 - 0.4 False Floating points are not reals. Even simple commutative laws don't hold. Vinzent. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Or even better, give a clear problem description. TASKS: First, is to count number of words inside the document. Second, is to count number of unique words inside the document. INPUT: Document format is using HTML-like format for storing articles. Here's the format: DOC (contains an article) |- DOCID (contains article's ID) |- TITLE (contains article's title text) |- TEXT (contains article's content text) CRITERIA: A word criteria are: - alphabetic (a..z) character sequence separated by whitespaces or hyphenation characters (space, tab, return, minus). - character sequence that contains non alphabetic character is NOT considered as a word, ignored it. - inside TITLE and TEXT tag, ignore anything inside DOCID. Unique word criteria is case-insensitive. So word and Word is considered a same word. EXAMPLE: DOC DOCIDTEMPO-022904-111/DOCID TITLEThis is the article title./TITLE TEXT This is The article-content 123abc. /TEXT /DOC would give result: Number of words = 10 Number of unique words = 6 10 words are 5 words from inside TITLE tag and 5 words from inside TEXT tag. The unique words are: this, is, the, article, title., and content. 123abc. is ignored since it contains numbers. The document may contain more than one article. Counting is done through out all articles found. My program (using TStrings) requires about 0.4s to process the given document. :( Tested on the same machine using FPC v.2.0.4. -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Bee schreef: TStrings is meant for GUI purposes. It's design and implementation are not optimized. Then its our task to optimize it more (and more) so it could as fast as Perl. What I meant here is using standard or default FPC's classes/units. ;) I don't count any third parties class/units/library or non standard attempt here since it'd require extra effort, especially for newbies or newcomers (to FPC). Of course, I know I can beat Perl using my own optimized TStrings written in assembler by hand mixed by pascal syntax. But, that's not the point. ;) The point is that you are probably using the wrong class (I have not seen your code). To do unique word counts, a hash table is more suitable that a string list. Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
TStrings is meant for GUI purposes. It's design and implementation are not optimized. Then its our task to optimize it more (and more) so it could as fast as Perl. What I meant here is using standard or default FPC's classes/units. ;) I don't count any third parties class/units/library or non standard attempt here since it'd require extra effort, especially for newbies or newcomers (to FPC). Of course, I know I can beat Perl using my own optimized TStrings written in assembler by hand mixed by pascal syntax. But, that's not the point. ;) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
I had never used Perl before. Until someone showed me Perl is very fast for text processing (using its powerful regex), despite it's an interpreted language. It even beat Delphi and FPC though both are compiled language. A few lines Perl program almost two times faster than a few pages pascal program. How can an interpreted language is faster than a compiled language (I assume both has been optimized well and using the best algorithm)? Can FPC improve its text processing related classes/units, so they can be faster than Perl (as it should be, logically)? Especially the TStrings class. Perl is about regex. They use regex even for stuff where regexes aren't necessary. Since Perl is so fixated on regex, it is likely the case where most time is spent. Moreover, regexes are relative tight statemachines, and most of the time of regex benchmarks is spent in it, and thus outside perl. TStrings is meant for GUI purposes. It's design and implementation are not optimized. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
TStrings is meant for GUI purposes. It's design and implementation are not optimized. Then its our task to optimize it more (and more) so it could as fast as Perl. What I meant here is using standard or default FPC's classes/units. ;) I don't count any third parties class/units/library or non standard attempt here since it'd require extra effort, especially for newbies or newcomers (to FPC). You can't separate performance from requirements. First define a problem, then a solution. Not the other way around. If you just want to show off, the easiest is simply making a FPC header to pcre, it might be useful even. Of course, I know I can beat Perl using my own optimized TStrings written in assembler by hand mixed by pascal syntax. But, that's not the point. ;) TString returns strings. A regex returns a boolean. This means that tstrings must always copy strings. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Arrays of objects
Hello, I'm seeking for advice about which is the best way to hold an array of class instances I need to access the elements using its position (like a regular array) , and also i'd like the structure to grow when I add more elements. Fpc has 'dynamic arrays' , and also there several classes like TFPList, TList in RTL.Classes . Also, the FCL has the contrns unit which also contains some classes that can be used for storing objects into memory. At this point there are already too many options, and I am unsure what to use. The 'dynamic arrays' are very close to what i'm looking for, except that I couldn't find the documentation page of the SetLength procedure. In particular : what happens if i call this procedure again for the same array : an does it re-allocate memory for the array , or resizes its memory ? Cheers, Adrian Maier ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Speed
On 31 Oct 2007, at 00:47, L wrote: And I'm sure you know you can always use GOTO statements when you really need speed out of loops Actually, in current FPC versions that will more often than not cause slowdowns, because the compiler cannot optimize as well when goto's are used. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Re: Why this evaluates on if wrong ?
The discussion about PI reminds me another funny quote: The primary purpose of the DATA statement is to give names to constants; instead of referring to pi as 3.141592653589793 at every appearance, the variable PI can be given that value with a DATA statement and used instead of the longer form of the constant. This also simplifies modifying the program, should the value of pi change. -- FORTRAN manual for Xerox Computers Oh, my GOD! I hope, in the current eternity, no change in the value of pi might occur! ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Bee schreef: If you just want to show off, the easiest is simply making a FPC header to pcre, it might be useful even. Making a header on top of other libraries written by other languages is showing that FPC is lack of powerful units/libraries. For some particular cases maybe it's alright. For example header over OS API, or over Apache, or over widgetsets (gtk, qt, wince, etc), or other common and huge libraries. But for basic or simple task like text processing, IMO we should provide it by ourselves (fpc). Maybe we should write our own pascal regex library that is more powerful than pcre, or at least equal. That way we could be more independent. ;) To give you a head start, check out: http://svn.freepascal.org/svn/fpc/trunk/packages/base/regexpr/ It needs testing and fixing. Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31 Oct 2007, at 10:40, Bee wrote: If you just want to show off, the easiest is simply making a FPC header to pcre, it might be useful even. Making a header on top of other libraries written by other languages is showing that FPC is lack of powerful units/libraries. It merely means you don't want to waste time on rewriting a perfectly good library simply because of abstract language purity reasons. It is completely irrelevant in what language a library is written if it works well with your program and does what you want. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
If you just want to show off, the easiest is simply making a FPC header to pcre, it might be useful even. Making a header on top of other libraries written by other languages is showing that FPC is lack of powerful units/libraries. For some particular cases maybe it's alright. For example header over OS API, or over Apache, or over widgetsets (gtk, qt, wince, etc), or other common and huge libraries. But for basic or simple task like text processing, IMO we should provide it by ourselves (fpc). Maybe we should write our own pascal regex library that is more powerful than pcre, or at least equal. That way we could be more independent. ;) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Adrian Maier wrote: Hello, I'm seeking for advice about which is the best way to hold an array of class instances I need to access the elements using its position (like a regular array) , and also i'd like the structure to grow when I add more elements TObjectList If you want specific non type casted code, write a wrapper that exposes the obvious methods and properties: type TMyObject = class public a: integer; end; TMyObjectListWrapper = class private flist: TObjectList; procedure SetItem(index: counter; item: TMyObject); function GetItem(index: integer): TMyObject; public function Count: integer; function Add(item: TObject): integer; procedure Delete(index: integer); procedure Clear; property Items[index: integer]:TMyObject read GetItem write SetItem; end; untested because I have no Pascal to compile with, but you get the jist. M ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
To give you a head start, check out: http://svn.freepascal.org/svn/fpc/trunk/packages/base/regexpr/ You read my mind! I've just been thinking about to use fpc's regex unit. :D It needs testing and fixing. How is it compare with regex that comes from FPC 2.0.4? I still can't upgrade to fpc 2.2.0 for some particular reasons. ;) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Speed
I hear the Intel C compilers and Fortran compilers and Ada compilers are better optimized for certain things since FPC/delphi are generally desinged for GUI programming. ;-) C/Fortran yes, Ada no; there exists no Intel Ada compiler. False. There's no speed penalty for writing in Ada vs C. They use the same Gnu compiler back-end, and thus the same assembler-level optimizations. Identical algorithms implemented in the two languages often produce indistinguishable performance. There are cases where an Ada compiler can get better performance than a C compiler, because the Ada compiler has more information to work with. -- Jilani KHALDI ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31 Oct 2007, at 11:00, Bee wrote: It merely means you don't want to waste time on rewriting a perfectly good library simply because of abstract language purity reasons. It is completely irrelevant in what language a library is written if it works well with your program and does what you want. Yes. If C is very good, I won't use pascal (especially fpc) at the first place. :-P Do you really not see the difference between a) code already written and tested by others b) code written by yourself The regexp library is case 1. A program using that library is case 2. Case 1 can be written in C because the original author prefers C. Case 2 can be written in Pascal because you prefer Pascal. Language superiority does not enter the picture. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Re: Why this evaluates on if wrong ? (more pi fun)
On Tue, Oct 30, 2007 at 07:36:39PM +0200, Musan Antal wrote: The discussion about PI reminds me another funny quote: The primary purpose of the DATA statement is to give names to constants; instead of referring to pi as 3.141592653589793 at every appearance, the variable PI can be given that value with a DATA statement and used instead of the longer form of the constant. This also simplifies modifying the program, should the value of pi change. -- FORTRAN manual for Xerox Computers Here is another funny pi quote (appearing in a footnote in a book on VLSI design): pi = sqrt(10) for small values of pi With apologies for the increasing off-topicness, Tom -- E-MAIL: T.Verhoeff @ TUE.NL | Dept. of Math. Comp. Science PHONE: +31 40 247 41 25| Technische Universiteit Eindhoven FAX:+31 40 247 54 04| PO Box 513, NL-5600 MB Eindhoven http://www.win.tue.nl/~wstomv/ | The Netherlands ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
It merely means you don't want to waste time on rewriting a perfectly good library simply because of abstract language purity reasons. It is completely irrelevant in what language a library is written if it works well with your program and does what you want. Yes. If C is very good, I won't use pascal (especially fpc) at the first place. :-P -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] fast text processing
Heck, I'm not even a programmer, and this kludge is
about 25% faster than your perl script on my machine
program koleski;
{$MODE OBJFPC} {$H+}
uses classes, strings;
var
f: text;
s:ansistring;
wc:longint=0;
wl, ul:TStringList;
i,n:LongInt;
begin
assign(f, 'Koleksi.dat');
reset(f);
wl:=TStringList.Create();
ul:=TStringList.Create();
ul.Sorted:=true;
ul.Duplicates:=dupIgnore;
while not eof(f) do begin
readln(f,s);
n:=length(s);
if (n0) then begin
StrLower(@s[1]);
if (s[1]='') then begin
if StrLComp(@s[1], 'title',7) = 0 then begin
delete(s,1,7);
end else continue;
end;
for i:=1 to n do if not (s[i] in ['a'..'z','0'..'9']) then begin
if ( s[i] '' ) then begin
s[i]:=#10
end else begin
s[i]:=#0;
SetLength(s,StrLen(@s[1]));
break;
end;
end;
wl.Text:=s;
for i:=0 to wl.Count-1 do begin
s:=wl[i];
for n:=1 to length(s) do if (s[n] in ['0'..'9']) then begin
s:='';
break;
end;
if (s'') then begin
inc(wc);
ul.Add(s);
end;
end;
end;
end;
close(f);
WriteLn('Word count:',wc, #10'Unique word count:', ul.Count);
end.
- Jeff
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Re: [fpc-pascal] fast text processing
Heck, I'm not even a programmer, and this kludge is about 25% faster than your perl script on my machine Nope. It's still more or less twice slower. :-D [EMAIL PROTECTED]:~$ time perl koleksi.perl Word count: 126944 Unique word count: 11793 real0m0.208s user0m0.204s sys 0m0.004s [EMAIL PROTECTED]:~$ time ./koleksi2 Word count:126944 Unique word count:11793 real0m0.452s user0m0.432s sys 0m0.016s -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
On 10/31/07, Matt Emson [EMAIL PROTECTED] wrote: Adrian Maier wrote: Hello, I'm seeking for advice about which is the best way to hold an array of class instances I need to access the elements using its position (like a regular array) , and also i'd like the structure to grow when I add more elements TObjectList I am aware that TObjectList is one of the possible ways. But I was hoping to get a better understanding about the purpose of these various classes or types of array , and more importantly what are the drawbacks . Is there really no wiki page , tutorial, anything that provides an overview of the collections and types of arrays that FPC has ? -- Adrian Maier ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] fast text processing
this kludge is about 25% faster than your perl script on my machine Nope. It's still more or less twice slower. :-D I guess it depends on the hardware: % time koleksi.pl # perl Word count: 126944 Unique word count: 11793 real0m1.019s user0m0.992s sys 0m0.028s % time koleksi # fpc Word count:126944 Unique word count:11793 real0m0.817s user0m0.784s sys 0m0.020s AMD-K6-700 / SuSE-10.3 / Linux-2.6.22 / perl-5.8.8 / fpc-2.2.0 - Jeff ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Jeff Pohlmeyer schreef:
this kludge is about 25% faster than your perl script
on my machine
Nope. It's still more or less twice slower. :-D
I guess it depends on the hardware:
% time koleksi.pl # perl
Word count: 126944
Unique word count: 11793
real0m1.019s
user0m0.992s
sys 0m0.028s
% time koleksi # fpc
Word count:126944
Unique word count:11793
real0m0.817s
user0m0.784s
sys 0m0.020s
AMD-K6-700 / SuSE-10.3 / Linux-2.6.22 / perl-5.8.8 / fpc-2.2.0
Thanks Jeff, for writing that parser code, I am not good in doing that.
I made it three times as fast on my computer (windows 2000, fpc 2.3.1, P4 1.5 Ghz)
using a hashlist for the unique word count. Using a larger textbuf gave an
additional 10% speed up:
program project1;
{$MODE OBJFPC} {$H+}
uses classes, strings, contnrs;
const
bufsize = $1FFF;
var
f: text;
s:ansistring;
wc:longint=0;
wl:TStringList;
uhl: TFPStringHashTable;
i,n:LongInt;
textbuf: array[0..bufsize-1] of byte;
begin
assign(f, 'Koleksi.dat');
reset(f);
SetTextBuf(f, textbuf, sizeof(textbuf));
wl:=TStringList.Create();
uhl:=TFPStringHashTable.Create;
while not eof(f) do begin
readln(f,s);
n:=length(s);
if (n0) then begin
StrLower(@s[1]);
if (s[1]='') then begin
if StrLComp(@s[1], 'title',7) = 0 then begin
delete(s,1,7);
end else continue;
end;
for i:=1 to n do if not (s[i] in ['a'..'z','0'..'9']) then begin
if ( s[i] '' ) then begin
s[i]:=#10
end else begin
s[i]:=#0;
SetLength(s,StrLen(@s[1]));
break;
end;
end;
wl.Text:=s;
for i:=0 to wl.Count-1 do begin
s:=wl[i];
for n:=1 to length(s) do if (s[n] in ['0'..'9']) then begin
s:='';
break;
end;
if (s'') then begin
inc(wc);
if uhl.Find(s) = nil then
uhl.Add(s,'');
end;
end;
end;
end;
close(f);
WriteLn('Word count:',wc, #10'Unique word count:', uhl.Count);
end.
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Re: [fpc-pascal] fast text processing
AMD-K6-700 / SuSE-10.3 / Linux-2.6.22 / perl-5.8.8 / fpc-2.2.0 Probably because the different fpc version, no? I'm using fpc 2.0.4. However, this is a good news. :) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
If you just want to show off, the easiest is simply making a FPC header to pcre, it might be useful even. Someone had worked on it using Delphi7 and PCRE. A little optimization is done on the TStringList, it uses CompareText instead of CompareStr for text comparison. It does faster than my program (using fpc and the default TStringList), but still about 40% slower than Perl. Plus, the program depends on PCRE library. :( (Probably the other way around, but that breaks MBCS (Delphi) and UTF-8(FPC) compability, and the internationalization of your GUI. So that is not something safe to do) You are not the first to optimize TStringList in this way, and will not the last. There are reasons why TStringList is as it is. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] fast text processing
the easiest is simply making a FPC header to pcre, it might be useful even. I did that, once upon a time... http://www.hotlinkfiles.com/files/526004_qpvr0/pcre-fpc.tar.gz -Jeff ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
I made it three times as fast on my computer (windows 2000, fpc 2.3.1, P4 1.5 Ghz) using a hashlist for the unique word count. Using a larger textbuf gave an additional 10% speed up: Arrrggg, I hate myself for not able to upgrade to fpc v.2.2.0! I can't find TFPStringHashTable on fpc v.2.0.4! :(( -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Adrian Maier wrote: On 10/31/07, Matt Emson [EMAIL PROTECTED] wrote: Adrian Maier wrote: Hello, I'm seeking for advice about which is the best way to hold an array of class instances I need to access the elements using its position (like a regular array) , and also i'd like the structure to grow when I add more elements TObjectList I am aware that TObjectList is one of the possible ways. But I was hoping to get a better understanding about the purpose of these various classes or types of array , and more importantly what are the drawbacks . Is there really no wiki page , tutorial, anything that provides an overview of the collections and types of arrays that FPC has ? You can use dynamic arrays, they work like an ansi string: var VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. -- Joao Morais ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Adrian Maier wrote: VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. ... Of the array itself. The objects it contains is another matter. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
On 10/31/07, Joao Morais [EMAIL PROTECTED] wrote: Adrian Maier wrote: On 10/31/07, Matt Emson [EMAIL PROTECTED] wrote: Adrian Maier wrote: Hello, I'm seeking for advice about which is the best way to hold an array of class instances I need to access the elements using its position (like a regular array) , and also i'd like the structure to grow when I add more elements TObjectList I am aware that TObjectList is one of the possible ways. But I was hoping to get a better understanding about the purpose of these various classes or types of array , and more importantly what are the drawbacks . Is there really no wiki page , tutorial, anything that provides an overview of the collections and types of arrays that FPC has ? You can use dynamic arrays, they work like an ansi string: var VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. The detail that is not crystal clear to me is : after the first SetLength and i set the first 3 elements , is it *guaranteed* that the second SetLength leaves those first 3 elements untouched ? That's what i meant by resize as opposed to reallocate . Reallocation could occur in some other place in memory , leading to loosing the original contents.I have actually tested it with a small program, but since i've been able to access indexes way beyond the allocated number of elements before getting the program killed i want to be sure that i understand the proper use of dynamic arrays. Thanks Joao ! -- Adrian Maier ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Marco van de Voort wrote: Adrian Maier wrote: VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. ... Of the array itself. The objects it contains is another matter. Which is why TObjectList is a good choice: TObjectList.Create(True) makes all instances added to the list owned by the list and free'd when the list is free'd. TObjectList also manages the allocation/deallocation and size for you. M ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Marco van de Voort wrote: Adrian Maier wrote: VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. ... Of the array itself. The objects it contains is another matter. Ah, yes, forgot to mention this. I usually use dyn arrays to manage objects owned by other lists or objects. -- Joao Morais ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Dear Joao, I do beleive that the SetLength only resize the array, ie: The Vetor has 3 elements like: Vetor[0]:= 1 Vetor[1]:= 2 Vetor[2]:= 3 And then eu want the same variable but with only 2 element, then SetLength(Vetor, 2) Vetor[0]:= 1 Vetor[1]:= 2 As you can see you don't lose the first 2, After that you want 4 elements on the same variable: SetLength(Vetor, 4) If you print the variable, before associate any value to it you will get: Vetor[0]:= 1 Vetor[1]:= 2 Vetor[2]:= 0 Vetor[3]:= 0 Hope it helped Lourival 2007/10/31, Joao Morais [EMAIL PROTECTED]: Marco van de Voort wrote: Adrian Maier wrote: VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. ... Of the array itself. The objects it contains is another matter. Ah, yes, forgot to mention this. I usually use dyn arrays to manage objects owned by other lists or objects. -- Joao Morais ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal -- Lourival J. Mendes Neto ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Lourival Mendes wrote: SetLength(Vetor, 2) Vetor[0]:= 1 Vetor[1]:= 2 As you can see you don't lose the first 2, After that you want 4 elements on the same variable: SetLength(Vetor, 4) If you print the variable, before associate any value to it you will get: Vetor[0]:= 1 Vetor[1]:= 2 Vetor[2]:= 0 Vetor[3]:= 0 I assume the same based on the rtl internals -- except that you cannot assume values from a newly allocated area (except if you are dealing with objects) -- Joao Morais ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31/10/2007, Bee [EMAIL PROTECTED] wrote: Vincent said it was 3 times faster. I expected the result would be about 0.10s. Or am I wrong? Maybe that's machine dependent I'll try the one without the hash table to see the difference. Otherwise, lets just compare the sys time and say it's 16x faster. ;-) Regards, - Graeme - ___ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Bee schreef: [EMAIL PROTECTED]:word_parser$ time ./project1 Word count:126944 Unique word count:11793 real0m0.185s user0m0.140s sys 0m0.000s [EMAIL PROTECTED]:word_parser$ time perl project1.perl Word count: 126944 Unique word count: 11793 real0m0.281s user0m0.244s sys 0m0.016s Vincent said it was 3 times faster. I expected the result would be about 0.10s. Or am I wrong? Maybe I have a relatively slow computer, so I get more speedup. Keep in mind, that disk time is constant. So for example, total time is disk time + processing time For me: StringList: 10 + 50 = 60 Hashtable: 10 + 10 = 20 Speedup: 3 times For Graeme with his faster computer (2x processor time): StringList: 10 + 25 = 35 Hashtable: 10 + 5 = 15 Speedup: 2.3 Please choose appropiate number to get to the result :-) Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Bee schreef: [EMAIL PROTECTED]:word_parser$ time ./project1 Word count:126944 Unique word count:11793 real0m0.185s user0m0.140s sys 0m0.000s [EMAIL PROTECTED]:word_parser$ time perl project1.perl Word count: 126944 Unique word count: 11793 real0m0.281s user0m0.244s sys 0m0.016s Vincent said it was 3 times faster. I expected the result would be about 0.10s. Or am I wrong? It was three times faster than the string list version of Jeff. I don't have a perl interpreter :-). Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31/10/2007, Vincent Snijders [EMAIL PROTECTED] wrote: Maybe I have a relatively slow computer, so I get more speedup. Keep in mind, that disk time is constant. I'm also not sure if FPC compiler parameters where used. I did. I compiled as:fpc project1.pas Anyway, here is the Hash Table vs No Hash Table results. Quite a difference in speed when using the hash table. [EMAIL PROTECTED]:word_parser$ time ./project1_nohashtable Word count:126944 Unique word count:11793 real0m0.291s user0m0.276s sys 0m0.004s [EMAIL PROTECTED]:word_parser$ time ./project1 Word count:126944 Unique word count:11793 real0m0.196s user0m0.132s sys 0m0.008s [EMAIL PROTECTED]:word_parser$ time perl ./project1.perl Word count: 126944 Unique word count: 11793 real0m0.292s user0m0.268s sys 0m0.000s [EMAIL PROTECTED]:word_parser$ Regards, - Graeme - ___ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
Adrian Maier wrote: On 10/31/07, Joao Morais [EMAIL PROTECTED] wrote: Adrian Maier wrote: On 10/31/07, Matt Emson [EMAIL PROTECTED] wrote: Adrian Maier wrote: Hello, I'm seeking for advice about which is the best way to hold an array of class instances I need to access the elements using its position (like a regular array) , and also i'd like the structure to grow when I add more elements TObjectList I am aware that TObjectList is one of the possible ways. But I was hoping to get a better understanding about the purpose of these various classes or types of array , and more importantly what are the drawbacks . Is there really no wiki page , tutorial, anything that provides an overview of the collections and types of arrays that FPC has ? You can use dynamic arrays, they work like an ansi string: var VArray: array of TSomeClass; begin SetLength(VArray, 10); // now you have VArray[0] .. VArray[9]; SetLength(VArray, 20); // now you have [0] .. [19]; // Length(VArray) = 20 // for I := 0 to Pred(Length(VArray)) is a valid statement They are reference counted, just like ansi strings, ie don't worry about memory leakages. The detail that is not crystal clear to me is : after the first SetLength and i set the first 3 elements, is it *guaranteed* that the second SetLength leaves those first 3 elements untouched? I don't use dyn array realocation by myself, but seeing this piece of code I'd assume yes: procedure TFPList.SetCapacity(NewCapacity: Integer); begin If (NewCapacity FCount) or (NewCapacity MaxListSize) then Error (SListCapacityError, NewCapacity); if NewCapacity = FCapacity then exit; ReallocMem(FList, SizeOf(Pointer)*NewCapacity); FCapacity := NewCapacity; end; -- Joao Morais ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Well done Vincent!! :-) I can confirm your results... [EMAIL PROTECTED]:word_parser$ time ./project1 Word count:126944 Unique word count:11793 real0m0.185s user0m0.140s sys 0m0.000s [EMAIL PROTECTED]:word_parser$ time perl project1.perl Word count: 126944 Unique word count: 11793 real0m0.281s user0m0.244s sys 0m0.016s Hardware: Intel P4 CPU 2.40GHz with 1Gig RAM FPC Compiler: v2.2.0 Regards, - Graeme - ___ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
[EMAIL PROTECTED]:word_parser$ time ./project1 Word count:126944 Unique word count:11793 real0m0.185s user0m0.140s sys 0m0.000s [EMAIL PROTECTED]:word_parser$ time perl project1.perl Word count: 126944 Unique word count: 11793 real0m0.281s user0m0.244s sys 0m0.016s Vincent said it was 3 times faster. I expected the result would be about 0.10s. Or am I wrong? -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31/10/2007, Vincent Snijders [EMAIL PROTECTED] wrote: Maybe I have a relatively slow computer, so I get more speedup. Keep in mind, that disk time is constant. I'm also not sure if FPC compiler parameters where used. I did. I compiled as:fpc project1.pas It could be wise to add -O3 for anything considered a benchmark :-) ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
On 10/31/07, Joao Morais [EMAIL PROTECTED] wrote: They are reference counted, just like ansi strings, ie don't worry about memory leakages. The detail that is not crystal clear to me is : after the first SetLength and i set the first 3 elements , is it *guaranteed* that the second SetLength leaves those first 3 elements untouched ? Yes. But they can be copied, so address to them might be invalid. That's what i meant by resize as opposed to reallocate . Reallocation could occur in some other place in memory , leading to loosing the original contents. It does resize if possible, reallocate (and copy the original data as far as it fits) else. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
I had never used Perl before. Until someone showed me Perl is very fast for text processing (using its powerful regex), despite it's an interpreted language. It even beat Delphi and FPC though both are compiled language. A few lines Perl program almost two times faster than a few pages pascal program. Alright everyone. The answers are enough. Now I can say confidently that pascal (fpc v.2.2) is FASTER than Perl, including in text processing. ;) Thank you very much to everyone who involves in this thread. :) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Re: Why this evaluates on if wrong ?
El mar, 30-10-2007 a las 19:36 +0200, Musan Antal escribió: Oh, my GOD! I hope, in the current eternity, no change in the value of pi might occur! I bet the circles will never will be the same if that happens.:P ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal -- Germán Pablo Gentile - PetroBox [EMAIL PROTECTED] Petrobox ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Speed
On Wednesday 31 October 2007 12:35, Daniël Mantione wrote: Further, it is unknown how well the GCC backend optimizes Ada language constructs as it is primarily designed for the C language. Well enough. In other words, optimization is about the same - given fairly equivalent code. The main difference is that the Ada compiler gets its knowledge from the variable declarations, while the C compiler gets it from the code. Vinzent. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
[ Charset ISO-8859-1 unsupported, converting... ] I had never used Perl before. Until someone showed me Perl is very fast for text processing (using its powerful regex), despite it's an interpreted language. It even beat Delphi and FPC though both are compiled language. A few lines Perl program almost two times faster than a few pages pascal program. Alright everyone. The answers are enough. Now I can say confidently that pascal (fpc v.2.2) is FASTER than Perl, including in text processing. ;) Thank you very much to everyone who involves in this thread. :) I don't think that everybody that saw: http://shootout.alioth.debian.org/gp4/benchmark.php?test=alllang=allcalc=Calculatexfullcpu=1xmem=0.5xloc=0binarytrees=1chameneos=0message=0fannkuch=1fasta=1knucleotide=1mandelbrot=1meteor=0nbody=1nsieve=1nsievebits=1partialsums=1pidigits=1recursive=1regexdna=1revcomp=1spectralnorm=1hello=0sumcol=1 ever doubted that. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31/10/2007, Marco van de Voort [EMAIL PROTECTED] wrote: It could be wise to add -O3 for anything considered a benchmark :-) It squeezed another 0.015s out of the time making it even faster. :-) Regards, - Graeme - ___ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Arrays of objects
On 10/31/07, Marco van de Voort [EMAIL PROTECTED] wrote: On 10/31/07, Joao Morais [EMAIL PROTECTED] wrote: They are reference counted, just like ansi strings, ie don't worry about memory leakages. The detail that is not crystal clear to me is : after the first SetLength and i set the first 3 elements , is it *guaranteed* that the second SetLength leaves those first 3 elements untouched ? Yes. But they can be copied, so address to them might be invalid. That's what i meant by resize as opposed to reallocate . Reallocation could occur in some other place in memory , leading to loosing the original contents. It does resize if possible, reallocate (and copy the original data as far as it fits) else. Thanks for the info! -- Adrian Maier ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31/10/2007, Bee [EMAIL PROTECTED] wrote: Alright everyone. The answers are enough. Now I can say confidently that pascal (fpc v.2.2) is FASTER than Perl, including in text processing. ;) Thank you very much to everyone who involves in this thread. :) That was fun!!! :-0 So what's the task for tomorrow? ;-) Regards, - Graeme - ___ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Marco van de Voort schreef: [ Charset ISO-8859-1 unsupported, converting... ] I had never used Perl before. Until someone showed me Perl is very fast for text processing (using its powerful regex), despite it's an interpreted language. It even beat Delphi and FPC though both are compiled language. A few lines Perl program almost two times faster than a few pages pascal program. Alright everyone. The answers are enough. Now I can say confidently that pascal (fpc v.2.2) is FASTER than Perl, including in text processing. ;) Thank you very much to everyone who involves in this thread. :) I don't think that everybody that saw: http://shootout.alioth.debian.org/gp4/benchmark.php?test=alllang=allcalc=Calculatexfullcpu=1xmem=0.5xloc=0binarytrees=1chameneos=0message=0fannkuch=1fasta=1knucleotide=1mandelbrot=1meteor=0nbody=1nsieve=1nsievebits=1partialsums=1pidigits=1recursive=1regexdna=1revcomp=1spectralnorm=1hello=0sumcol=1 ever doubted that. But people who have seen http://shootout.alioth.debian.org/gp4/benchmark.php?test=regexdnalang=all may have doubted that. I wonder where fpc would end up in that list, A: if it uses its own regexpr parser (atm not good enough) B: if it uses Jeff's header translations for pcre Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Bee schreef: But people who have seen http://shootout.alioth.debian.org/gp4/benchmark.php?test=regexdnalang=all may have doubted that. Vincent, are we connected or what?! I was about to post the very exact URL! :-D I wonder where fpc would end up in that list, A: if it uses its own regexpr parser (atm not good enough) B: if it uses Jeff's header translations for pcre I prefer it would use fpc own regexpr unit instead of using other language libraries. IMO, it'd show the power of pascal (fpc) by itself. ;) Sure, but as Jonas pointed out it is better to use a good library than the write a bad library yourself. Feel free to improve the regexpr unit, if you want it to be used. Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On 31/10/2007, Graeme Geldenhuys [EMAIL PROTECTED] wrote: That was fun!!! :-0 So what's the task for tomorrow? ;-) for tomorrow the homework is: improve fpc regexp capability and get fpc in the top 5 on the regex-dna shootout ratings ;) Regards, - Graeme - henry ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Sure, but as Jonas pointed out it is better to use a good library than the write a bad library yourself. And someone would claim that the speed comes from the library (c?), not from pascal. :P It's a LANGUAGE shootout btw, not LIBRARY shootout. Maybe you had forgotten that. ;) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Bee schreef: Sure, but as Jonas pointed out it is better to use a good library than the write a bad library yourself. And someone would claim that the speed comes from the library (c?), not from pascal. :P It's a LANGUAGE shootout btw, not LIBRARY shootout. Maybe you had forgotten that. ;) A. That is not a problem. A couple of other, non-c participants use pcre. B. The same is done with pidigits. C. It shows that fpc has good interoperability. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On Wednesday 31 October 2007 14:19, Bee wrote: Sure, but as Jonas pointed out it is better to use a good library than the write a bad library yourself. And someone would claim that the speed comes from the library (c?), not from pascal. :P It's a LANGUAGE shootout btw, not LIBRARY shootout. Maybe you had forgotten that. ;) Well, considering that perl's or Python's speed greatly rely on the underlying C-implementation of (at least) particular functionality, all those comparisons basically boil down to C vs. C, anyway. Or don't they? ;) Vinzent. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
A. That is not a problem. A couple of other, non-c participants use pcre. I myself would consider them lacks of the language advantage on their own. B. The same is done with pidigits. C. It shows that fpc has good interoperability. We could submit more than one programs, one using fpc own regepxr unit, another using pcre. This way we would also implicitly/indirectly compares regepxr performance between fpc own regexpr against other libraries, besides the good interoperability of fpc. ;) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Well, considering that perl's or Python's speed greatly rely on the underlying C-implementation of (at least) particular functionality, all those comparisons basically boil down to C vs. C, anyway. Or don't they? Exactly! That's why I prefer to use fpc own regexpr unit. :) -Bee- has Bee.ography at: http://beeography.wordpress.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Vincent Snijders schrieb:
Jeff Pohlmeyer schreef:
this kludge is about 25% faster than your perl script
on my machine
Nope. It's still more or less twice slower. :-D
I guess it depends on the hardware:
% time koleksi.pl # perl
Word count: 126944
Unique word count: 11793
real0m1.019s
user0m0.992s
sys 0m0.028s
% time koleksi # fpc
Word count:126944
Unique word count:11793
real0m0.817s
user0m0.784s
sys 0m0.020s
AMD-K6-700 / SuSE-10.3 / Linux-2.6.22 / perl-5.8.8 / fpc-2.2.0
Thanks Jeff, for writing that parser code, I am not good in doing that.
I made it three times as fast on my computer (windows 2000, fpc 2.3.1,
P4 1.5 Ghz) using a hashlist for the unique word count. Using a larger
textbuf gave an additional 10% speed up:
program project1;
{$MODE OBJFPC} {$H+}
uses classes, strings, contnrs;
const
bufsize = $1FFF;
var
f: text;
s:ansistring;
wc:longint=0;
wl:TStringList;
uhl: TFPStringHashTable;
i,n:LongInt;
textbuf: array[0..bufsize-1] of byte;
begin
assign(f, 'Koleksi.dat');
reset(f);
SetTextBuf(f, textbuf, sizeof(textbuf));
wl:=TStringList.Create();
uhl:=TFPStringHashTable.Create;
while not eof(f) do begin
readln(f,s);
n:=length(s);
if (n0) then begin
StrLower(@s[1]);
if (s[1]='') then begin
if StrLComp(@s[1], 'title',7) = 0 then begin
delete(s,1,7);
end else continue;
end;
for i:=1 to n do if not (s[i] in ['a'..'z','0'..'9']) then begin
if ( s[i] '' ) then begin
s[i]:=#10
end else begin
s[i]:=#0;
SetLength(s,StrLen(@s[1]));
Why not SetLength(s,i)? StrLen is _very_ expensive. I don't see a way
how another #0 can be before.
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Re: [fpc-pascal] fast text processing
Florian Klaempfl schreef: Vincent Snijders schrieb: Jeff Pohlmeyer schreef: s[i]:=#0; SetLength(s,StrLen(@s[1])); Why not SetLength(s,i)? StrLen is _very_ expensive. I don't see a way how another #0 can be before. That is right, I am working on a version which does not do that anymore. Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Speed
On 31 Oct 2007, at 19:11, L wrote: Further, it is unknown how well the GCC backend optimizes Ada language constructs as it is primarily designed for the C language. I assumed that people used not just GNU Ada compilers.. for serious work. But I'm not sure. For example, what do Airplanes use? GNU? I'd laugh if Richard Stallman controlled the Boeing and rocket ships ;-) Sorry for flamebait. Please use the fpc-other list for things like that. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
On Wed, 31 Oct 2007 13:56:04 +0100 (CET) [EMAIL PROTECTED] (Marco van de Voort) wrote: [ Charset ISO-8859-1 unsupported, converting... ] I had never used Perl before. Until someone showed me Perl is very fast for text processing (using its powerful regex), despite it's an interpreted language. It even beat Delphi and FPC though both are compiled language. A few lines Perl program almost two times faster than a few pages pascal program. Alright everyone. The answers are enough. Now I can say confidently that pascal (fpc v.2.2) is FASTER than Perl, including in text processing. ;) Thank you very much to everyone who involves in this thread. :) I don't think that everybody that saw: http://shootout.alioth.debian.org/gp4/benchmark.php?test=alllang=allcalc=Calculatexfullcpu=1xmem=0.5xloc=0binarytrees=1chameneos=0message=0fannkuch=1fasta=1knucleotide=1mandelbrot=1meteor=0nbody=1nsieve=1nsievebits=1partialsums=1pidigits=1recursive=1regexdna=1revcomp=1spectralnorm=1hello=0sumcol=1 ever doubted that. Does someone know, why java 6 -server is that fast? Mattias ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Speed
For example, what do Airplanes use? GNU? Ada compilers must be certified, so if you are developing software for avionics *you have* to write your software with a compiler certified for avionics development. JK ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Well, considering that perl's or Python's speed greatly rely on the underlying C-implementation of (at least) particular functionality, all those comparisons basically boil down to C vs. C, anyway. Or don't they? Exactly! That's why I prefer to use fpc own regexpr unit. :) -Bee- Or you can use TRegexp or regexp2.pas units.. But from my testing, TRegexp is a bit slow on big files. Not sure if the latest TRegexp is faster: http://www.regexpstudio.com/TRegExpr/TRegExpr.html L505 ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Word count: 126944 Unique word count: 11793 real0m0.281s user0m0.244s sys 0m0.016s Can someone do a test for 5 minutes of parsing and see if things slow down or speed up for one of the programs? That takes away process load time too.. example: the time it takes to fork the process. Not sure if perl scripts are initially faster since you don't have to fork a process, assuming perl is already in memory waiting for the script. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Word count: 126944 Unique word count: 11793 real0m0.281s user0m0.244s sys 0m0.016s Can someone do a test for 5 minutes of parsing Rather I mean can someone do a more realistic test such as parsing 1500 files instead of one single file. At least in my line of work, I never parse one single file.. it is usually about 1500 or more at a time. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Op Wed, 31 Oct 2007, schreef Vincent Snijders: Florian Klaempfl schreef: Vincent Snijders schrieb: Why not SetLength(s,i)? StrLen is _very_ expensive. I don't see a way how another #0 can be before. No more strlen: http://www.hu.freepascal.org/fpcircbot/cgipastebin?msgid=1432 One more possible speedup: Why are you using strlower and strlcomp instead of lowercase/pos? The latter ones are probably faster and they don't care of code pages which are not relevant in this example. Daniël___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] fast text processing
Florian Klaempfl schreef: Vincent Snijders schrieb: Why not SetLength(s,i)? StrLen is _very_ expensive. I don't see a way how another #0 can be before. No more strlen: http://www.hu.freepascal.org/fpcircbot/cgipastebin?msgid=1432 Vincent ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] When Pascal code is too fast
Am Donnerstag, den 01.11.2007, 00:45 +0200 schrieb ik:
Hi List,
I have a weird problem. the fpWrite is too slow for FPC code. When
I have the same exact code in C that writes a big amount of buffers of
the same size with the same content. It seems that the fpWrite is way
too fast, and the can't handle another call in the loop, and I need to
slow down the loop using usleep.
At the beginning I thought that it was a problem with fpWrite, so I
created my own binding, but still the problem is the same.
Except then the fact that it seems that FPC is much faster the GCC,
any other ideas for such a behavior and what might be the reasons for
it ?
A POC for such code btw, can be as follows:
Pascal:
...
while not EOF(f) do
begin
readln(f,s);
fpwrite(f2, S[0], length(S));
end;
C:
...
while (! feof(f)) {
s_size = fread(f, s, MAX_BUFFER);
write(f2, s, s_size);
}
...
What error do you get? Lastly I had something similar with fpc writing
to fast to a non-blocking stderr channel. I haven't had time to do for
my code, but if you get ressource temporartily unavailable-like errors
switching the file to blocking mode might help.
Something like
fcntl(fileno(stderr), F_GETFL) O_NONBLOCK
or the pascal equivalent should do.
HTH,
Marc
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Re: [fpc-pascal] fast text processing
On 01/11/2007, Vincent Snijders [EMAIL PROTECTED] wrote: No more strlen: http://www.hu.freepascal.org/fpcircbot/cgipastebin?msgid=1432 Wow, that version improved quite a bit from the previous one!! [EMAIL PROTECTED]:word_parser$ time ./project1_fast Word count:126944 Unique word count:11793 real0m0.107s user0m0.100s sys 0m0.000s [EMAIL PROTECTED]:word_parser$ time perl ./project1.perl Word count: 126944 Unique word count: 11793 real0m0.271s user0m0.248s sys 0m0.008s Regards, - Graeme - ___ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
