|
PureBytes Links
Trading Reference Links
|
John,
You are only making the case that proper organization is the
responsibility of the programmer. Programming is a sharp sword. You
can slice up your problems with it, or you can cut yourself. It is
all in the technique. And yes, I also need to be reminded of what I
wrote last month and why.
My include statements in the main program are not one-liners. There
is a comment block at the start of each include file that documents
what is in there -- like a table of contents. I paste that whole
block into my main program. That way I have the top level
documentation of what is included -- usually a list of functions with
parameter names and a short description of why to call it. If I
search for a function, it will come across the definition in the
include comments. Each function in a file has its own comment block.
Though I don't make a point of documenting every little change or bug
fix, I do note the last change date on each one.
Outside of a major block of inline code, blocks of functions are what
I think of as AFL language extensions. So I might have one include
called FP_UtilityFunctions.afl that adds a dozen useful general
purpose stand alone functions to AFL independent of trading program
specifics.
On the other hand, I have FlexibleParam_Buttons.afl that adds many new
functions that specifically support on-chart button arrays. It has a
lot of functions and many of them call each other and must be
compatible as a set. It would be pure insanity to figure out how the
whole set worked without being able to see all the code and comments
together in the same file.
Then I have an include called FP_BtnBarInfo.afl that implements a
specific button/table of bar information -- a bar inspector. It is
not a function, but inline code that includes parameter definitions,
layer mouse click claim code, and a procedure called DrawBarInfo()
that draws the buttons on the screen with Gfx commands. That has to
be called later in reverse order of of all the buttons because there
are no Z layers for Gfx commands, or else it would be part of the
inline code.
I would suggest that your proposal would actually make things more
obscure from my point of view if I tried to use it as you are
suggesting. Then there is the problem of the compiler. It is not
really a compiler to any greater sense than most interpreters have.
It is not multi-pass for resolving references. The preprocessor is as
close to a compiler pass as it has, and it only looks at a few
specific commands like #include. It would have to be able to parse
the whole syntax to look for functions that are undefined, try to find
them in a file, add them to a special buffer that is always executed
initially as part of the AFL pass. This would be a lot of pain for
little gain. If you understand the simple elegance of the AFL
execution process, you would see that this is just wrong.
I am quite happy with the general concept of include files as opposed
to external functions. As I have pointed out, I lends the perfect
level of modularity to my programming. It also helps with revision
control that I only have one AFL trading program -- with a thousand
parameters. If I had many different trading programs, then I would
likely add a version number to the include file names for non-backward
compatible revisions, and leave the old ones alone.
Keep the blade away from you own arms and legs. ;-)
Best regards,
Dennis
On Feb 12, 2009, at 6:18 PM, Listsub wrote:
> Dennis,
>
> Interestingly I started out with same view as yourself regarding
> grouping related functions into one include file. Although it went
> against my past experience it was appealing because it seemed a
> quicker path to the business of developing and testing trading
> systems. Over time I found this approach did not work well for me
> and I switched to one per file. Reasons it didn't work?
>
> I found tracking code changes awkward. For example I knew a function
> group had been changed but which function within it and why?
> Keeping track of dependencies.
> Forgetting which functions were in which files - my age;-)
> Putting the wrong includes in programs - often redundant - age
> again ;-)
> Silly stuff like what group shall I put this function in - I ended
> up with 3 big files called Misc1, Misc2, Misc3!
>
> As you say working with large numbers of files is a challenge. A
> good Editor, version control and well organised folders help.
>
> Thanks for your ideas.
> John
>
>
> ----- Original Message -----
> From: "Dennis Brown" <see3d@xxxxxxxxxxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Thursday, February 12, 2009 2:58 AM
> Subject: Re: [amibroker] Re: Run time debugging for includes
>
>
>> John,
>>
>> Although I would not take advantage of some of what you are
>> suggesting, still you make some good points, and you got me thinking
>> about things that I could use.
>>
>> I would prefer to have a group of related functions in an include
>> file, rather than just one function per file. That way with one
>> include file I get a whole new functional set that are edited
>> together
>> to stay compatible version wise. Otherwise my 40 files would
>> become a
>> confusing 200+ files. Too much for me! There is a fine line between
>> not enough modularity and too much modularity. If I do want the
>> modularity, then the include can be written to follow the rules of a
>> function that you describe for scope.
>>
>> Right now, the include path names are constants because they are
>> preprocessed. I would like to have preprocess commands to set an
>> override default path for includes folder. That way one definition
>> in
>> the main code before the include could override the default include
>> folder path. One easy edit to get a new set, or reorganized to a
>> subfolder.
>>
>> #IncludeFolderPathOverride = "path" or <path> to relocate to a
>> relative subfolder
>> #Include <FilePath>
>> #IncludeFolderPathRestore
>>
>> The override is really a push, and the restore is a pop for multiple
>> levels. That way you could substitute a new path for just a portion
>> of the includes that you are testing without hard coding a fixed path
>> for each one.
>>
>> Your point #4 below is also an interesting one and could be applied
>> to
>> the include file path.
>>
>> Best regards,
>> Dennis
>>
>>
>> On Feb 11, 2009, at 8:38 PM, Listsub wrote:
>>
>>> As noted debugging AB with includes is not easy . The nature of AFL
>>> makes it quick and easy to write/test simple stuff but as complexity
>>> grows debugging any sizeable AFL project can be quite tricky,
>>> particularly if running RT as there is a lot going on.
>>>
>>> "Modular" programming is only catered for in AB by Includes (which
>>> is just a soure code copy preprocessor). The AB program structure
>>> model is therefore basically just one big chunck of code - which is
>>> why (unless you are very careful what you code inside Inlcudes) you
>>> can get some very hard to find problems (the problems can even
>>> change or disappear depending on the roder of Includes).
>>>
>>> IMO improving AFL to support procedure/function calls to external
>>> files would be a big plus to enabling better modular program design.
>>> Specifically:-
>>>
>>> a =xyx(p1,p2) would call the external proc/func "xyz" (unless xyz
>>> is defined in current source file).
>>>
>>> The benefits as I see them:-
>>>
>>> 1. #Inlcudes are no longer required for procs/fucntions.Compiler
>>> would pull them from library specified via preferences. No more
>>> searching for which Include file is that function in, which version
>>> of that was I using .. etc.
>>>
>>> 2. External functions matched by filename. i.e one function name =
>>> one filename, no ambiguity, easily portable.
>>>
>>> 3. External files are closed boxes - can only receive/pass data via
>>> parameters, return value or global variables. Everything else inside
>>> file is local. No interference bewteen files.
>>>
>>> 4. Faster code development/maint. For example if we have the
>>> facility in Preferences to define multiple paths to external proc/
>>> func library it becomes easy to test out changes without having to
>>> resort to all the usual suffixing fillenames, changing calls etc.
>>> i.e.
>>>
>>> path1=AB_Function_Library_Test
>>> path2=AB_Function_LIbrary_Live
>>>
>>> So to test out a mod just copy the function file to the Test
>>> library, make the changes and test. Compiler searches paths in order
>>> specified so anything with matching name in Test takes precedence
>>> over same name in Live.
>>>
>>> 5. Easier debugging? ;-)
>>>
>>> John
>>>
>>>
>>> ----- Original Message -----
>>> From: "jtoth100" <jtoth100@xxxxxxxxxxx>
>>> To: <amibroker@xxxxxxxxxxxxxxx>
>>> Sent: Wednesday, February 11, 2009 2:26 PM
>>> Subject: [amibroker] Re: Run time debugging for includes
>>>
>>>
>>>> Hi all,
>>>>
>>>> debugging includes is not easy and handy in any script language. So
>>>> instead of making the GUI to reduce clicks my suggestion would be
>>>> to
>>>> reduce possible error cases.
>>>>
>>>> Most errors come from undefined/uninitialized variables. If AFL
>>>> language would have an "OPTION" to require definition of all
>>>> variables then most common errors could be vanished.
>>>> Visual Basic 6.0 never was my favorite language and environment. It
>>>> was for average Joe to do basic level programming. It did not
>>>> require
>>>> declaring variable just like AFL or any script language. But I
>>>> had to
>>>> use it years ago. At that time all serious developer started each
>>>> module in VB with "Option Explicit On". This caused an error at
>>>> parse/compile time if a variable was not defined explicitly but was
>>>> referenced anywhere in the code.
>>>>
>>>> How would it help?
>>>> Most probles come from just creating variables by assigning a value
>>>> to an "identifier". However if you misstype an "identifier" or code
>>>> execute in a code path where variable does not get
>>>> defined/initialized you get an error. The worst thing is that these
>>>> errors are hidden until the rearly executed code path is executed
>>>> (typical runtime error). If definition of variables are required
>>>> even
>>>> these code paths are checked for proper variable usage.
>>>>
>>>> This should be an option for advanced users which is turned on on
>>>> purpose. So all code out there could run with no change.
>>>>
>>>> Variable assignment and definition could be merged to one statement
>>>> like in any modern language (e.g.: var x = 0.5;) This way
>>>> declaration
>>>> is required and initialization can be done as well.
>>>>
>>>> I know it does not guaranty that all runtime error are gone. But
>>>> with
>>>> disciplined coding most can be avoided and the need for debugging
>>>> is
>>>> vastly reduced.
>>>>
>>>> So I would not go for GUI change request but to improve AFL as a
>>>> script language.
>>>>
>>>> Regards,
>>>>
>>>> Y
>>>>
>>>>
>>
------------------------------------
**** IMPORTANT PLEASE READ ****
This group is for the discussion between users only.
This is *NOT* technical support channel.
TO GET TECHNICAL SUPPORT send an e-mail directly to
SUPPORT {at} amibroker.com
TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
http://www.amibroker.com/feedback/
(submissions sent via other channels won't be considered)
For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
http://www.amibroker.com/devlog/
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/amibroker/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/amibroker/join
(Yahoo! ID required)
<*> To change settings via email:
mailto:amibroker-digest@xxxxxxxxxxxxxxx
mailto:amibroker-fullfeatured@xxxxxxxxxxxxxxx
<*> To unsubscribe from this group, send an email to:
amibroker-unsubscribe@xxxxxxxxxxxxxxx
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|