Is there anything wrong with this?

So, we all think reusing other code and not reinventing the wheel is generally a good thing.

And using Moose is generally good.

So, I want to test if something is an object. I am using Moose.

1) Create a large hash to compare keys against, and then do

my $not_object_ref = {
  HASH => 1, ARRAY => 1, GLOB => 1,...
};

my $is_object;
if ( my $ref = ref $object ) {
  if ( ! $not_object_ref->{$ref} ) {
    $is_object++;
  }
}

# stuff that uses boolean value of $is_object

2) Use a Moose Attribute and eval

has q{_i_am_an_object} => (
  isa => q{Object},
  is => q{rw},
);

sub _is_object {
  my ( $self, $object ) = @_;
  my $is_object = 0;
  eval {
    $self->_i_am_an_object( $object ); # test if this is an object
    $is_object++;
  } or do {}; # I like PBP and perl critic :)
  return $is_object;
}

my $is_object = $self->_is_object( $object );
# stuff that uses boolean value of $is_object

I don't know if this is a pure abuse of the Moose Attribute system, or if there is a much neater way of doing it, but certainly it has merit over the whole keeping track of what refs are not objects. And certainly, if you want to check against the object type, you change the isa to the class name, and give it a better method name.

It's probably more of an abuse of eval :)

Andy

When not to shift...

I'm not a big fan of 'shift @array'. And I have just sealed why I think that is.

Anyone who has looked at my code will see that my methods always use array assignments

sub my_method {
  my ( $self, $arg_refs ) = @_;
}

Even if it is just $self, rather than

sub my_method {
  my $self = shift;
}

Today, I further found another bug whilst testing. I'm trying out Test::MockObject, and know that I want to return an arrayref, with 1 element in the array.

The code loops through 8 times, and I expect a result from this array each time, since the webservices I am mocking would provide this.

However, in my tests, I get a result of 1 true, rather than 8.

Why is this?

I check the arrayrefs are the same with some debug (they are). I check the array length each time through. 1st time, 1. All other 7, 0.

The reason is that instead of just assigning

my $ref_seq = $arrayref->[0];

I have shifted

my $ref_seq = shift @{ $arrayref };

So of course, I have within the code removed the element off the array, rather than leave it there, and since $arrayref goes out of scope in the code as soon as $ref_seq is assigned, either works.

This is one time when I would expect the 'real world' to have still been fine, but my 'test environment' can't cope.

Obviously, there are times when shift is most appropriate, i.e. you deliberately need to truncate out the first element because you must not allow that to get somewhere else as the array carries on, but that niggling little voice that keeps telling me never to shift has finally had a reason to give me.

Still, liking Test::MockObject :)

It's been a while

It has been a while since I last blogged. Unfortunately, family health problems are still not in a resolved state, so it probably will be so again.

However, last week, I went on Dave Cross's advanced perl course/seminar. In fact, most of my team did.

Dave knew his stuff (and apologised that he was talking about the 'new' 5.10 when 5.12 was released less than 36 hours earlier).

The course was interesting, however, due to the limitations of time (1 day isn't long enough, and I do like Lab-time) we didn't cover as much about Moose/DBIx::Class/Catalyst than I would have liked.

However, he did cover Test::Builder, which I hadn't really seen before, and how to create your own bespoke tests which will fit in with the plan.

And so I just have.

I have released Test::Structures::Data today. At the moment it only exposes one method

is_value_found_in_hash_values

Now, this is not to detract from Test::Deeply (which I like a lot!) or Test::Data::Hash, however, I could not find any methods which go to see if a value is present in a data structure, and this was particularly what I was after.

It is on CPAN

http://tinyurl.com/y5owods

and my github repository is

http://github.com/setitesuk/Test--Data--Structures

I plan to add some other methods shortly. These are meant to be simple things though. For example, you may have a hash, and a value. You don't know which key the value should be for, or even care which key it belongs to. The above test just sees if it can find it in the hash values.

Hoping this might be of use to someone (anyone?)

Andy

Retrieving the $schema object from the resultset object

More for my own personal reference

Within a resultset (row) object

my $schema = $self->result_source->schema();

Example reasoning

User wants to be able to obtain (via helper method) all the public groups s/he doesn't belong to

sub public_usergroups {
my ($self) = @_;

my $schema = $self->result_source->schema();

my @public_usergroups = $schema->resultset('Usergroup')->search({
id_usergroup => {
'NOT IN' => $self->user2usergroups->get_column('id_usergroup')->as_query,
},
is_public => 1,
});

return @public_usergroups;
}

The returned set are then also Usergroup objects, so they have the methods relating to those.

BarCamb3

Ive just been one of the lucky 20 to get a shiny ticket to BarCamb3 in the first batch of tickets released. WooHoo! Just hope now that my wife is better so that I can go.

More tickets are to be released next week, and the following week.

I went to the first 2 BarCambs, which where hosted by Matt Wood at the Wellcome Trust Sanger Institute. They were very interesting events, and I spoke at the 2nd one with a presentation called 'It's Too Much Information For Me', which came to me when I was 5 minutes away from the event in the car, thinking about a Duran Duran song and even the group hadn't been played on the radio.

That's the great thing about BarCamps. They are unconferences, so pretty much anything goes. You turn up on the day, with or without anything to talk about. Mill around having coffee, and put your name up to speak with a topic, or don't, or join some others.

The website for BarCamb is

http://barcamb.ltheobald.co.uk/

and the sponsors this year are Red Gate Software, Paypal and Taylor Vinters Solicitors.

I don't yet know what to talk about/discuss yet. Perhaps it will again come to me in the car. Also, I don't know how 2 days will be filled up, but whatever happens, it is bound to be interesting, and I'm hoping Simon turns up with Mbed again. (I want to play this year please!)

Andy

Artificial Intelligence vs the human brain

Here is a plea to all people working on Artificial Intelligence.

Please think about what you are doing, and try to avoid loose wiring.

My wife has suffered from Post-Natal depression ever since the birth of our son 4 and half years ago. Yesterday, I took her into hospital again to ensure that she is safe (she is plagued by voices at the moment) whilst the new medication ramps up to a level which is therapeutic for her.

This, as you may expect, is quite distressing for all of us. We have support systems in place though, and my work are being frankly fantastic about it all.

It gets me thinking though. I can program computers to get them to behave in particular ways, but how do you rewrite the programming in a brain.

I recently read 'Pragmatic Thinking and Learning - Refactor your Wetware' by Andy Hunt (www.pragprog.com).

This is great for yourself, or even trying to suggest to others. I have found some easy to apply tips and some which I need to get round to trying, but one thing it shows is that we have set ways of doing things. Our Logic/Linear-mode (L-mode) tends to be dominant, and seems to have the most influence, unless, as the book suggests, we deliberately try to get information from our Rich-mode (R-mode).

The key thing with this though is that we control the flow of information, we determine if we will do it. We seem to have a controlling Sensible-mode (S-mode).

And this is what I like about Computer Programming. A computer really only sources from L-mode, and it allows the L-mode to control it. So I can write a program that is logical, instructs the computer, and it doesn't get anything else influencing it (well, assuming I have taken care of external running factors such as OS, file locations...)

My wife though, is not controlling her own thoughts. What is, we don't know, but not her. Her S-mode seems to lose it's control. Whether the thoughts are L-mode or R-mode based (traditionally, it would look like those things are "Right-brain" thought processes, although when she explains her thoughts, you could argue the Logic-mode is having a say).

Luckily, this time, my wife's S-mode seems to be working enough to stop her finishing the act, but she is getting somewhere close to it (popping enough pills out of a blister pack, but at the last minute, throwing them in the bin instead of taking them).

So where am I going with this.

My opening request is to think about AI, and not introduce loose wiring. Truly Artificial Intelligence should be able to think both in L-mode and have R-mode, but with an overriding S-mode to control all the thoughts.

I like programming because what I produce only has to act logically. I am in turmoil because my wife has some 'loose wires' which are not allowing her to act completely rationally, and I can't fix the bug in the program to correct it.

If AI is a true goal of the computer technology industry, then lets hope that the coding which goes into it won't allow for the loose wires which screw up the controller, or else we might just have a lot of depressive machines which need careful looking after whilst we feed them lots of pill programs to try to make them better.

Here's hoping that the pills my wife is now taking soon start to sort out her programming. I'm glad I never became a psychiatrist.

crontab or daemon

So here is an interesting choice I need to make.

I have just rewritten a bit of code to email interested parties when a run with their data on it reaches 2 points. One when it reaches run complete (i.e. the instrument has done all it's processing) and then again when the data has been post-processed and qc'd and deposited in the central archive space for them to obtain.

I'm quite pleased with the code. It is more robust than the previous hack which we had never intended to be all encompassing, and actually mails the parties that should be interested (rather than some 'user' which may or may not be the right person).

It is, of course, also written using Moose.

However, now I have to decide, which do I choose, a cronjob, or a daemon process.

Cronjob:

Pros - very quick. Just decide how often to launch it, and run the script.
Cons - need to remember which node the cronjob is running, need to do something with the outputs (logs, etc), need to ensure that jobs don't relaunch on top of each other

Daemon:

Pros - Use a monitor to keep us informed it is still running, cyclical so won't launch over each other, write to a log file easy
Cons - Need to write a daemon controller script

I'm sure that there are others, I'm mostly babbling and writing this down as I think. Certainly, for the first release of this, I will start it as a cronjob, but down the line, I think I will move this to a Daemon, once the script has been in a production environment for a while. (i.e. we know it is working correctly!)