Re: Geolocation services: what's good, what's not?
On 3 Dec 2014, at 01:18, Peter Sergeant p...@clueball.com wrote: The first question I'd ask anyone considering using anything other than MaxMind's Geo2IP product is Why aren't you using MaxMind's Geo2IP product? Seconded. Cheap (I expect you can get away with the free dataset for this purpose!), great quality and easy to integrate. James
Re: windmill blades turning?
On 17 Oct 2014, at 09:02, Nicholas Clark n...@ccl4.org wrote: Single Malt not Malt beer! I wasn't really aware of what malt beer is. Having now looked it up, most definately, malt whiske?y. When I lived in Shepherd’s Bush, it was everywhere. I think I’ve only ever seen one person with a bottle, mind. Although a pint of scotch is always an option, in the right parts of the world. I believe lathos described it as a london.pm drinking game called “have a shot every time you have a shot”. James
Re: Getting the latest related record from a SQL DB
On 9 Oct 2014, at 22:36, Abigail abig...@abigail.be wrote: This assumes no artist releases two albums at the same time. Not really, it’s just that in that case it will only return one, which is probably acceptable behaviour. But that’s why the declarative nature of sql is brilliant, I can tell you exactly what it will do without running it. James
Re: Getting the latest related record from a SQL DB
On 10 Oct 2014, at 16:37, Abigail abig...@abigail.be wrote: MySQL disagrees with your assessment: Of course it does. Because otherwise I might have had a point. While we’re at it, did I make any egregious spelling errors? James
Re: Schwartzian transform
On 13 Aug 2014, at 11:12, Alex Balhatchet ka...@slackwise.net wrote: D'oh. Thanks for schooling me on 'map EXPRESSION' gents. I do vaguely remember seeing that before, but I never use it so I completely forgot about it :-) It’s amazing what you can fit into an expression (especially with parens), and the expression form runs a little faster. grep EXPR is also really useful for doing regex matches over a list and it becomes more obvious what it’s doing at first glance. James
Re: [ANNOUNCE] London PM Leadership Change
On 8 Aug 2014, at 23:53, Sue Spence virtually...@gmail.com wrote: Thank you. I didn't quite follow the last sentence, though. Daves and Women are fairly well understood collections of individuals with no observed overlap (so far). The other two terms are generally understood to be roughly equivalent. :-) I think he was asking how women stack up against Daves in the subset of “London.pm leaders”. Daves have almost certainly got that one nailed, surely? James
Re: [ANNOUNCE] London PM Leadership Change
On 9 Aug 2014, at 09:31, Dave Cross d...@dave.org.uk wrote: It's one-all surely? Are you seriously saying that you’re the only Leader we’ve had called Dave? That seems… implausible, given Dave distribution. James
Re: Deploying perl code
On 25 Jul 2014, at 08:52, Ben Tisdall b...@tisdall.de wrote: However, I would urge you to spend a day each investigating Ansible SaltStack, the latter in salt-ssh mode if you want to make a direct comparison. Both of the aforementioned tools do ad-hoc remote execution, task orchestration and configuration management. Ansible I do like for the most part, but there are a few sharp edges. I don’t think it was usable up until they put out 1.3 (was it 1.3? it’s been a while since i’ve written a playbook) which added a bunch of useful stuff in the standard library — I was running out of git master for ages. I don’t think it’s the right solution for this case, though. Salt: just no. Really no. I’m really surprised to see a recommendation for it, because it’s a terrible piece of software. James
Re: Deploying perl code
On 25 Jul 2014, at 09:40, mascip mas...@gmail.com wrote: and the idempotence: you can run a playbook as many times as you like, it should have just the same effect as running it once (true for most Ansible things). That’s in stark contrast to my experiences. I found ansible requires you to think about the side effects of everything so that you can write idempotent code. Where the default puppet library and constraint resolution mode of thinking basically gives you the idempotence for free, ansible pushes the responsibility back to the developer. Chef is even worse at this. Without idempotence for free, the only compelling reason to use it over a shell script is the reusable roles. James
Re: Deploying perl code
On 25 Jul 2014, at 11:54, Andrew Beverley a...@andybev.com wrote: The main problem is that it seems to be a victim of its own success: there is a huge backlog of merge requests. I'd like to provide some simple patches to a couple of modules to make them work better for me, but have little hope that they'd be merged this side of Christmas. I provided a really simple patch a while ago - it's not been touched and now no longer merges cleanly. I won’t even try and submit a patch after my experience reporting a documentation bug. I was at the time regularly tweeting with their CTO, so I let him know on twitter. He then pointed me at the bug tracker, where I proceeded to file my bug. Immediately, ‘ansibot’ informed me that my bug would be closed in a few days if I didn’t reformat my bug to correspond with their designated format for bugs, which included such things as “steps to reproduce” (because you know, we all have difficulty reproducing documentation bugs). I think the only way I actually got that doc bug fixed was by complaining loudly and repetitively on twitter about how ridiculous their processes are, but they showed absolutely no willing to make it easier to contribute towards their projects, so I’m showing absolutely no willing to help them grow their company. /j
Re: Deploying perl code
On 24 Jul 2014, at 17:25, David Cantrell da...@cantrell.org.uk wrote: I'm looking for tools that will make it easy to go from a bunch of code in a release branch on github to an updated bunch of servers, with minimal downtime. If it matters we're using Debian. Is this the sort of thing that puppet and chef are for? If you've used them are they as awesome as the hype makes out, or will they just push me into the same murderous rage as our current bunch of incomplete shell scripts do? Puppet/chef isn’t going to work terribly well for this model, imo. I suspect what you’re looking for is capistrano ( or Tak, the perl equivalent (and mst-ware!) ). Puppet is *shitty* if you’re wanting to deal with anything to do with versioning - it makes you go set up a repository server where you pin the versions by hand. I’m always going to recommend you build an app-specific perl and deploy that via rpm/deb, but whether you should build an os package of your code, well, depends on your code. I’m thinking from the sound of this, capistrano would be a better fit. And if your jenkins isn’t already singing the single-button deployment song, make it do so*. James * My company provides consultancy on such matters, if such a thing would interest you and your budget has increased since the last time we spoke about it ;)
Re: Deploying perl code
On 24 Jul 2014, at 18:59, David Cantrell da...@cantrell.org.uk wrote: On Thu, Jul 24, 2014 at 06:34:08PM +0200, James Laver wrote: And if your jenkins isn?t already singing the single-button deployment song, make it do so*. That does, of course, depend on our code being easily deployable. We're a long way from that at the moment. It's something to consider once I can type 'myappdeploy live' and be confident that it will Just Work. Then I’ll double down on my capistrano/tak recommendation. If that’s what you want, it seems like the right tool for the job. Cap is ruby, so perhaps Tak may be more what you want. Or not. I don’t know. James
Re: [ANNOUNCE] Reminder: Tech Meet this Thursday 7pm at Conway Hall
On 23 Jul 2014, at 10:09, Vytautas D vyt...@gmail.com wrote: All the trafficparking aside, there are quite a few of us coming from southampton.pm, hence it's much cheaper option.. I would really consider driving to “much closer” and finishing the journey off with public transport. It will save congestion charge and dependent on where, probably parking as well. James
Re: Interview - a Dancer in London:)
Be careful of yaks. I went to write some blogging software and I've made 10 modules releasable since, but still no blog. James Sent from my BlackBerry 10 smartphone. 2. From user requirement to open source project: the birth of a CPAN module. Andy
Re: Character encodings and databases
On 19 Jun 2014, at 15:58, Andrew Hill london...@welikegoats.com wrote: 1. Data is not being stored in the database as UTF8 - not sure how to check when Perl is the only tool available to query it 2. Conversion is occuring in the DBD driver Yes. I don’t know the oracle version of it, but many DBD adapters provide a method to set the charset, or a magic SQL command you can execute. James
Re: Evaluating user-defined conditions
On 10 Jun 2014, at 09:26, Andrew Beverley a...@andybev.com wrote: I'm happy to be restrictive to the user, and only allow straightforward strings in double quotes. So anything else is removed or not allowed, and the strings in quotes are checked as above. I would not be surprised if I've missed something though! Andy I was sort of hoping that the not too subtle hints that using eval is a bad idea would pay off. Apparently not. Perl is quite complicated. You’ll keep missing things until you’re sick of patching security holes. Don’t do it. James
Re: Evaluating user-defined conditions
On 9 Jun 2014, at 12:39, Abigail abig...@abigail.be wrote: In short, Safe.pm may be the answer, but depending on who your users are, it may be overkill, or still contain too many hooks for an attacker. In short, if you trust the input, just eval() it, and if you don’t, you want a parser. You might consider transforming it automatically into postfix notation and building a really simple stack machine if you just want basic arithmetic and placeholders. Otherwise, I can recommend Parse::RecDescent. Perhaps you can be cheeky and get them to write some yaml like this: operation: + with: - 1 - operation: - - with: - 2 - operation: * - with: [3,4] Not very user friendly, but very easy to work with. It depends how much effort you’re willing to put in and whether you trust the input. James
Re: Module namespace for projects
On 22 May 2014, at 09:59, Andrew Beverley a...@andybev.com wrote: Hi guys, I'm creating a Perl project that I hope to eventually release (a Postfix filter to add signatures to outgoing emails). My aim is to eventually release it as a Debian package. A stupid question, but I'm a bit unsure about how I should define the namespace for my project's modules. Do I need to slot any program modules into the CPAN namespace? So, for example, I'll have a module to manage all the database aspects. Let's say the program will be called emailsig and I use Emailsig::DB for the database queries. Presumably the module Emailsig::DB would eventually need to be installed under /usr/share, so should I actually be naming the module something like Email::Emailsig::DB? Following on from the above, should I then be uploading the modules to CPAN? Grateful for any advice! Andy Hi Andy, First thing I’d say is give your project a short-ish name so that if you do release it to the cpan, you won’t die of RSI. Second thing is to pick a root Module name that doesn’t clash with something in cpan. Other than that, don’t worry. So you’d still be able to have Emailsig::DB. Besides, I wouldn’t worry about eventually now, and when you do, I’d expect you’ll decide there are better approaches than what you describe. If the modules are something you think would be useful to someone else, then please do upload them. Or at least make them easily available on github. James
Re: emergency social meet June 11
On 20 May 2014, at 13:43, Randal L. Schwartz mer...@stonehenge.com wrote: And is this mic on? Or am I drinking by myself? :( Despite the fact you’re a supercite quoter (*g*, *fist shake*), I’m liable to be up for it if reminded much closer to the time. James
Re: Finding the intersection between two regexes
On 21 Apr 2014, at 09:45, Dirk Koopman d...@tobit.co.uk wrote:
This may be related to the question I asked recently about turning (up to) a
few hundred REGEXes into one giant REGEX. The goal being to test all those
disparate REGEXes in the most efficient way possible on a string.
Sounds like an implementation detail.
My reading of the problem was this:
package Evil;
use Moose;
has regexen = (
is = ‘ro’,
default = sub { [] },
traits = [‘Array’],
handles = {
add_regex = ‘push’,
res = ‘elements’,
},
);
sub go {
my ($self, $datum) = @_;
for my $r ($self-res) {
return 0 if $datum !~ $r;
}
1;
}
__PACKAGE__-meta-make_immutable;
1;
__END__
Re: XP-Replacement for Parents
On 27 Mar 2014, at 23:42, Wendy G.A. van Dijk nl...@wendy.org wrote: Scanners I never had luck with scanner support on Windows XP, always stupid errors. This behaviour of idiots working on drivers at the scanner manufacturers is continued for support in Ubuntu. It just sucks always. Almost none of the extended options promised, ever work for me. Not back than in XP, and not now in Ubuntu. I just have to scan my shit to a USB stick, and copy the files to my computer later. Universal law of conservation of suckdom. (slightly OT…) Scanners and printers are the source of most of my historical frustrations with computers. I’ve finally achieved hardware peripheral nirvana by buying a Scansnap S220m (sheet-fed) and a cheap lexmark laser and plugging them into my mac, whereupon scanning becomes “launch scansnap software, hit button on front of scanner” and printing just works. Before this, I more or less gave up because I’ve never had much luck. The part where software has to touch the real world is where it all goes wrong. James
Re: You make a lovely teddy bear
On 28 Mar 2014, at 12:18, Mallory van Achterberg stommep...@stommepoes.nl wrote: On Thu, Mar 27, 2014 at 04:37:35PM +, David Cantrell wrote: So I'd like to thank you all for being my teddy bear: http://cm.bell-labs.com/cm/cs/tpop/debugging.html I thought it was called rubber duck, for some reason... Also: cardboard man. I used to keep a rubber duck on my desk for this purpose, and a former boss used to make a great cardboard man despite knowing nothing about programming (he was smart, just lacked programming knowledge). James
Re: XP-Replacement for Parents
On 27 Mar 2014, at 12:07, Alex Balhatchet ka...@slackwise.net wrote: On another topic if you want something that looks like Windows XP but acts like Ubuntu I've read good things about Lubuntu[2]. In this vein, many Linuxes ship LXDE now. My old favourite foresight does, but there aren’t as many packages for it as there used to be, sadly. James
Re: XP-Replacement for Parents
On 27 Mar 2014, at 17:01, Smylers smyl...@stripey.com wrote: Yeah, if I end up doing this in person that'd be a sensible way to proceed. Or even otherwise. Ubuntu has built in VNC support. If you can walk your mother through setting up reverse SSH tunnel*, you’d be able to do it for her, remotely. James * Well, it’s only one command. You’d need a bounce box though.
Re: Web scraping frameworks?
On 4 Mar 2014, at 22:10, DAVID HODGKINSON daveh...@gmail.com wrote: For what I'm thinking, a way of relating named divs (and lists of) on a page to the hash elements needed for poking into DBIx::Class. As for Web::Scraper, it's Miyagawa-ware, so definitely worth looking at. Sounds like what you actually want is a handful of app-specific lines of code around HTML::TreeBuilder. You can fetch with LWP (maybe LWP::Simple if your needs are small) or WWW::Mechanize for more complex stuff, or whatever else. FWIW, last time I got involved in web scraping, this approach worked quite well and while it’s not immediately reusable, it’s pretty straightforward. James
Re: Web scraping frameworks?
On 4 Mar 2014, at 23:15, Hernan Lopes hernanlo...@gmail.com wrote: Another usual problem is data coersion, it can be done at the moment data is read. Or, it can be right before the moment data is written/saved. Of course the latter is probably the best option in most cases. The creaton of the crawler for each site must be as fast as possible and with the less hassle, ie, data coersion, encodings problems, parsing data according to content types if each crawler must implement all that, its not going to be fun. Its going to be a nightmare. The web scrapping frameworks exist to take care of all those parts and simply dispose objects your recipe can use to scrap each site already with the correct encoding and parsed module. Imagine if you read prices, and every time you read a price $ 20,000.00 you must coerse it into 2.00 That operation can be done for each site/template which would not be fun. Better just grab $ 20,000.00 and before writing on database, coerce into 2.00. This is more reusable. and if needed it can evolve into better parsing methods. S, $startup is importing data from an external webservice which is actually json (but it’s so shit it may as well be screenscraping). We elected to clean it up on entry. It really simplifies the massive amounts of other processing that happen down the line. In fact, I’d say it’s just not doable any other way. James
Re: sub signatures coming
On 25 Feb 2014, at 03:45, Paul Makepeace pa...@paulm.com wrote:
On Mon, Feb 24, 2014 at 2:04 PM, Steve Mynott steve.myn...@gmail.com wrote:
http://perltricks.com/article/72/2014/2/24/Perl-levels-up-with-native-subroutine-signatures
Finally. But don't believe the python/perl comparison troll, as
python, for once, actually outguns perl on a character chomping basis,
sub pairwise_sum ($arg1, $arg2) {
return map { $arg1-[$_] + $arg2-[$_] } 0 .. $#$arg1;
}
def pairwise_sum(list1, list2):
return [i + j for i, j in zip(list1, list2)]
Paul
But I probably already have List::MoreUtils imported (because Perl).
sub pairwise_sum ($a1, $a2) {
zip @$a1, @$a2;
}
And lets ignore the fact that the perl version that was used in the article was
buggy. If $arg2 is shorter than $arg1 it breaks. zip’s supposed defined
behaviour is to stop when either list runs out of elements.
James
Re: sub signatures coming
On 25 Feb 2014, at 11:18, James Laver james.la...@gmail.com wrote:
But I probably already have List::MoreUtils imported (because Perl).
sub pairwise_sum ($a1, $a2) {
zip @$a1, @$a2;
}
And lets ignore the fact that the perl version that was used in the article
was buggy. If $arg2 is shorter than $arg1 it breaks. zip’s supposed defined
behaviour is to stop when either list runs out of elements.
James
Oh, for bonus fun, I’d do it a different way in clojure (using a map):
(def pairwise-sum zipmap)
You might also have fun assuming clojure.zip[1] has anything to do with the
zipmap function. If you actually figure out what a ‘zipper’ is, do please let
me know because it’s been evading me for about a year.
James
1. http://clojuredocs.org/clojure_core/clojure.zip/zipper
Re: sub signatures coming
On 25 Feb 2014, at 11:31, Matt Lawrence matt.lawre...@virgin.net wrote:
On 25/02/14 11:18, James Laver wrote:
But I probably already have List::MoreUtils imported (because Perl).
sub pairwise_sum ($a1, $a2) {
zip @$a1, @$a2;
}
And lets ignore the fact that the perl version that was used in the article
was buggy. If $arg2 is shorter than $arg1 it breaks. zip’s supposed defined
behaviour is to stop when either list runs out of elements.
Whereas this one is buggy because it doesn't actually do what it says on the
tin. Where's the summation?
Matt
Ah yes. I’d just woken up.
sub pairwise_sum($a2,$a2) {
map {shift($_)+shift($_)} (zip @$a1, @$a2);
}
James
Re: consolidate regexes
On 25 Feb 2014, at 16:45, Nicholas Clark n...@ccl4.org wrote: Vendor supplied perl is going to be slower than one you compile yourself. Or at least, it won't be faster. Historically this wasn’t always the case*. When ubuntu first got going, their packages were a little faster to load than other distros because they were the first to use LDFLAGS=-O1 That, and that it does take a little bit of domain knowledge to know how to properly tune for what it is you’re doing. Many sysadmins do not have this experience. James * No, I’m not going to forget the Dead Rat bless/overload madness in a hurry, either.
Re: [ANNOUNCE] Damian Conway Speaking at London.pm: Monday, 10th March
Sent from my BlackBerry 10 smartphone. Original Message From: Nicholas Clark Of those, GIR 0AA breaks the pattern for postcodes, doesn't it? No number in the out code. GIR0AA breaks everything. It's non-geographic for a start. And i'm not sure the girobank exists any more. James
Re: [ANNOUNCE] London Perl Mongers March Social - 2014-03-06 - The Antelope SW1W 8EZ
On 19 Feb 2014, at 21:32, Ash Berlin ash_c...@firemirror.com wrote: Good pub that one - or it used to be when London.pm went there last time… which was when Simon Wistow was not yet our Ex-Glourious Leader. Wow that dates it. Not quite true. We were there just before Ovid fled to Europe. James
Re: smutty british expression?
On 13 Feb 2014, at 09:46, Dominic Thoreau domi...@thoreau-online.net wrote: You'll generally get change from a fiver for *a* pint, but not two. Unless you're drinking really rubbish stuff, or inside a Sam Smiths' pub. (at least in London. Which Arthur's house wasn't.) Sam Smiths pubs are no longer a cheap option. In fact, the last one I drank in wound me a pretty big bill come the end of the night. On the other hand, their chocolate stout should make youngs embarrassed about their double chocolate stout. James
Re: Recommended IDE...?
On 17 Jan 2014, at 10:18, Andrew london...@unitedgames.co.uk wrote: Looking to try using an Integrated Development Environment. Is there an industry standard everyone uses and I should get familiar with, or will any do? My previous experience is with NotePad and TextWrangler. I've Windows98SE and OSX 10.5.8 [Leopard] ;-), and use both in tandem via a KVM switch, XD. It’s rather a personal choice. If you’re writing Perl, I don’t think you need anything other than a text editor. Komodo IDE has a lovely interface for debugging though. My emacs configuration is quite IDE-like in many respects. I expect many people have VIM configs that do more for you as well. In terms of actual IDEs, the standard is eclipse, I prefer Komodo. It really is intensely personal. Try a few. James
Re: One off job helping with Linux partition
On 9 Jan 2014, at 19:34, Guinevere Nell guinevere.n...@gmail.com wrote: Hi all, Hi, I’m having a little bit of difficulty following here. I am a latent perl programmer (was NY.pm in the day, YAPC 19100, etc) - it's been a few, um 5 or 6, years since i have coded regularly - and I've just tried installing Ubuntu on my windows 8 machine with no success - had no cd drive and it complained and then won't let me boot in - Are you saying that you do not have a CD drive? How did you try and install umbongo without one - usb key? Or are you instead saying that you booted into umbongo, it told you you didn’t have a CD drive then kicked you out and now you can’t get back in to either OS? If you’ve got a backup, how did you take it? Assuming everything you require is in that backup, I think you should be able to sort this out yourself without too much hassle. So the questions: - How many partitions are currently on that disk? - Are any of them bootable at all? - How did you attempt the installation? USB key? - Which image did you download and how did you write that to whatever installation medium? - Do you have a CD drive? - Does the backup have all of the files you need? James
Re: [ANNOUNCE] London.pm Social - 2nd January 2014 - Gunmakers
Should you be needing respite from a period of overindulgence, you’ll be out of luck at our January social. For the rest of us, we’ll be enjoying foamy beer, fruity ciders and fragrant wines and possibly a bit of food to cap it off with (not that this was in short supply recently for most of you I’ll wager). We haven’t been to the Gunmakers in quite a long time now, but we’re going back in the only month of the year we have a chance of getting a social there. As per usual, people who haven’t attended a social before will get a free (as in beer!) pint. Find us. We’ll be the ones that look like perlmongers. I’ll be there from about 6pm. The Gunmakers, 13 Eyre St Hill, Clerkenwell EC1R 5ET http://thegunmakers.co.uk/ James
Re: EMERGENCY SOCIAL . . .
On 4 Dec 2013, at 16:03, Th. J. van Hoesel th.j.v.hoe...@gmail.com wrote: around 5.15 I will be at Victoria Station... let's meet anywhere uptown and drink and eat and chat and maybe you will end up at NLWP::2014 Theo Since noone else has stepped up to the plate, I nominate the Bag o’ Nails. Or rather Dave Cross nominates it and I’m announcing it. Meet you there around 5:15. Everyone else can feel free to pop along as well. http://www.beerintheevening.com/pubs/s/45/453/Bag_O_Nails/Victoria James
Re: EMERGENCY SOCIAL . . .
Arrived. Nice pub. Good choice Dave. James Dave Cross d...@dave.org.uk wrote: Quoting James Laver james.la...@gmail.com: On 4 Dec 2013, at 16:03, Th. J. van Hoesel th.j.v.hoe...@gmail.com wrote: around 5.15 I will be at Victoria Station... let's meet anywhere uptown and drink and eat and chat and maybe you will end up at NLWP::2014 Theo Since noone else has stepped up to the plate, I nominate the Bag o’ Nails. Or rather Dave Cross nominates it and I’m announcing it. Meet you there around 5:15. Everyone else can feel free to pop along as well. http://www.beerintheevening.com/pubs/s/45/453/Bag_O_Nails/Victoria I'm suggesting it as my default pub in the Victoria area. but I'm afraid I won't be able to be there this evening. Theo - I'm still looking forward to your Number::Fraction patches :) Dave... -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
Re: Regex teaser
On 3 Dec 2013, at 23:54, Paul Makepeace pa...@paulm.com wrote: What does this output? $ perl -le '($a = aabbb) =~ s/b*$/c/g; print $a’ You can tell you’ve been writing perl too long when you know what that’s going to do and why :( Here’s your example modified to exhibit my favourite regex madness. Can you explain this one? perl -le '($a = aabbb) =~ s/.*?/./g; print $a’ James
Re: I have a bikeshed, colour suggestions appreciated
On 4 Dec 2013, at 01:17, Kent Fredric kentfred...@gmail.com wrote: On 4 December 2013 13:40, Yitzchak Scott-Thoennes sthoe...@gmail.com wrote: Is it spell correcting the domain names? It should use And the colours we're providing simply aren't in our browsers dictionary. So ... its interpreting it as hex. And non hex characters as 0’s I always wondered why ‘monkey’ was a bright blue. http://monkey.bikeshed.org/ James
Re: Best practices for database migrations
Simon Wistow si...@thegestalt.org wrote: Is there a current favourite for doing database migrations (i.e having a programatic way for a database to upgraded to a new version by having a series of sql commands run on it)? There are quite a few ways of doing it. What database are you using? If postgres you can do this in pure DDL/SQL with transactions and a unique constraint on your migrations table (but up and down are different files). If not postgres, I recommend ragtime (clojure) which manages the same interface for a jumber of databases from the command line through lein. Ragtime: https://github.com/weavejester/ragtime James -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
Re: Best practices for database migrations
On Mon, Nov 18, 2013 at 2:13 PM, Edmund von der Burg e...@ecclestoad.co.uk wrote: On 18 November 2013 02:01, Simon Wistow si...@thegestalt.org wrote: Is there a current favourite for doing database migrations (i.e having a programatic way for a database to upgraded to a new version by having a series of sql commands run on it)? However the Python/Django crowd do have http://south.readthedocs.org/en/latest/about.html which is probably 90% of the solution for 99% of the likely scenarios. I suspect it is similar to the active record approach, and well worth a look by anyone proposing to create a database migration toolset, especially the easy rollback support. South is mostly lovely, except when you have a MySQL database. I've found in practice you need to squash migrations a lot to avoid difficulties if you're working off MySQL (South helpfully warns that it wouldn't be a problem if you got a real database). The guy who wrote south has written the schema migrations stuff that's now in core django in 1.7 and it seems to work very well. South is quite hacky for reasons that will become obvious when you've used it for a while. Obvious downside here is that it requires you keep a copy of your models in Python rather than SQL. There's also quite a lot you can't do to your database in django's model system and muttley may want that. Oh, and I mistakenly trolled muttley early by linking to ragtime. I was actually meaning drift, https://github.com/macourtney/drift , but it looks like the joke about sexps came in quite by accident :) James
Re: Database Design Advice
Smylers smyl...@stripey.com wrote: William Blunn writes: Instead of storing a version ID (e.g. 1, 2, 3, 4, 5, 6), you could store a SERIAL. So for one document ID, you might store versions 10, 11, 12, 50, 75, 87. This was my immediate thought as well, but I'd probably cheat and declarr the document version numbers to be oureky decorative and thus the realm of userspace to turn them into 1,2,3,4,5 etc. -- one can, after all fix this with a single line of code. Performance (and complexity) would be much better than triggers -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
Re: Database Design Advice
Mark Stringer m...@repixl.com wrote: From the OP: But version should start at 1 for each document and be consecutive. I'll grant that I've assumed that was to be more friendly to the end user, but in that case, it really is just cunning use of the .. operator. I'd guess that the date_created is being stored in the table, so could be used to order the records without the need for a serial, if ordering is the only concern. Personally I would opt for timestamps by preference, but that brings in a longer requirements chat. How does backdating revisions work? Do you need a separate key to order in that case? Etc. James -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
Re: Database Design Advice
On Fri, Nov 8, 2013 at 10:06 AM, Smylers smyl...@stripey.com wrote: James Laver writes: This was my immediate thought as well, but I'd probably cheat and declarr the document version numbers to be oureky decorative ^^ “purely”, I presume? Yes. Phone keyboard, sorry. and thus the realm of userspace to turn them into 1,2,3,4,5 etc. -- one can, after all fix this with a single line of code. True. I'm all for cheating. But reporting will be done by Crystal Reports connecting directly to the database (and there's a distinct possibility that there will end up being more than one code base (in different programming languages) using the database too), so I'd rather any serial-number-to-per-document- version-number conversion was handled in the database, so it's in just one place. That conversion could be abstracted by a view, so the complexity is hidden for somebody just doing a SELECT — but my attempts with the Rank() window function seem like too complex complexity to be worth it. In this case, a view seems like the best solution. But if you're going to materialise it for extra performance, then you're back in the world of triggers (assuming eager materialisation), and back comes the complexity :( James
Re: Database Design Advice
On Fri, Nov 8, 2013 at 11:43 AM, Smylers smyl...@stripey.com wrote: • Separate fields for discount_percentage and discount_amount. This has the disadvantage of needing to ensure that a record doesn't have both fields set. If the business concocts another discount type in future, this will require a field for each discount type. I'd probably actually go for this and a trigger. The particular case of discounts means it's unlikely they'll add another, and this seems like the most straightforward way to deal with it. Relational databases aren't always great for modelling things, so when it's unclear what's the best solution, it's usually best to go for simple. James
Re: Database Design Advice
On Fri, Nov 8, 2013 at 5:22 PM, Yitzchak Scott-Thoennes sthoe...@gmail.com wrote: On Fri, Nov 8, 2013 at 12:38 AM, Mark Stringer m...@repixl.com wrote: I'd guess that the date_created is being stored in the table, so could be used to order the records without the need for a serial, if ordering is the only concern. Never use date/times as unique identifiers/sort keys. I'll agree with the former, but what's the reasoning behind the latter? James
Re: Multi argument open and STDERR
On 3 Oct 2013, at 21:26, Paul Weaver paul.wea...@bbc.co.uk wrote: How can I capture STDERR? You're looking for IPC::Open3, I suspect. Certainly it's the closest analogue to the way you're doing it that I can think of. http://perldoc.perl.org/IPC/Open3.html I also note that ffmpeg is a strange beast and has a fairly undocumented remote control mechanism. At least I think that was ffmpeg. That only requires STDIN/STDOUT. James
Re: Could use some hotel/travel help
On 26 Sep 2013, at 05:29, Kieren Diment dim...@gmail.com wrote: Mornington Crescent. (with apologies) Surely only at the end of his trip? Given he wants Euston, it's less silly than it sounds, but Camden is a bit gauche. I'm rather fond of the Great Northern Hotel at King's Cross (or at least it's a favourite brunch spot), but it's definitely not a cheap option. Alternatively how about somewhere lovely in Somers Town (Euston)? Bloomsbury would also be convenient and is quite beautiful. Again, an easy walk into Euston. Fitzrovia would put you one stop away (Warren St) or a slightly longer walk and is also quite lovely with some great eating. James
Re: Could use some hotel/travel help
On Thu, Sep 26, 2013 at 11:05 AM, Kieren Diment dim...@gmail.com wrote: Yeah, but I already won. Ungetlemanly as my strategy was. -- Sent from my phone, so please excuse spelling mistakes, top posting, brevity etc. You were in Nidd. Also, we were playing Mornington Croissant.* James * http://www.isihac.co.uk/games/mcvariations/mc-m.html
Re: Robot turtles
On Mon, Sep 23, 2013 at 1:22 PM, Joel Bernstein j...@fysh.org wrote: I'm not aware of any 3-8 year olds in this group, am I missing the point? A number of london.pm members are parents. It seems fairly likely they'd want their kids to grow up knowing at least a little about programming. James
Re: Perl publishing and attracting new developers
On 20 Sep 2013, at 07:46, gvim gvi...@gmail.com wrote: I doubt that, judging by the tone of your replies. Welcome to London.pm, home of robust discussion. Oh well, I should have known better than to engage in discussion with someone whose email address begins with abuse. Have a nice life. Back in the day, using abuse@ emails cut down on spam massively. If you genuinely believe you're trying to have an intelligent debate here, I'm amazed at the level of self delusion, because if you take trolling out of it it just comes off as a huge whine about the state of reality. James
Re: Perl publishing and attracting new developers
On Fri, Sep 20, 2013 at 4:19 PM, Adrian Howard adri...@quietstars.com wrote: Publishers are in the business of making money. They *vastly* prefer to sell to an existing market, rather than try to create one. Technical books are a trailing indicator of interest, not a leading one. I can't really think of any counter examples. We already *have* good general books for introducing the relative newbie to Perl. Programming Perl, Learning Perl, Modern Perl Beginning Perl all spring to mind. I don't think adding more is going to produce more Perl devs. The fact that they behave responsively doesn't mean they aren't part of the causative loop. Knowing you want to program something and finding a preponderence of ruby books in the shop means you're more likely to pick one up and learn ruby. James
Re: Perl publishing and attracting new developers
On Thu, Sep 19, 2013 at 9:46 AM, Kent Fredric kentfred...@gmail.com wrote: On 19 September 2013 19:41, Philippe Bruhat (BooK) philippe.bru...@free.frwrote: That book needs a chapter about the secret operators. ;-) I disagree, I don't see much value in promoting esoteric ways to use Perl. We just need to promote things that are good, and things that are awesome, and things that make programming in Perl *better*, things that serve as compelling arguments to use a more modern Perl, things that serve to inspire people to use more *CPAN* I'm actually inclined to write such a book. Anyone interested in coauthoring please message offlist and we can see if there's any mileage in it. James
Re: return \@array or @array
On Thu, Sep 12, 2013 at 5:05 PM, Jérôme Étévé jerome.et...@gmail.com wrote: I'm still not quite sure about the real benefit of return \@array though. There isn't one. In fact, there are downsides to using it if you don't need it, like accidentally modifying in two places where you only wanted to modify in one. Python passes by reference by default and I see a lot of code that makes a shallow copy to avoid such bugs. So passing by value helps eliminate a whole category of programming bug. In any case, it's an interpreted programming language. Write bits that have greater performance requirements in XS. Or don't write them in perl at all. James
Re: return \@array or @array
On 12 Sep 2013, at 20:23, Daniel de Oliveira Mantovani daniel.oliveira.mantov...@gmail.com wrote: My benchmark does show that. Look again. Wrong. Copy-on-write semantics. Aside from the fact you're being odious in public again, arguing with Abigail is generally not likely to result in you being proven right. James
London.pm Dim Sum, Leong's Legends, Thursday 12th September 13:00
Motivated by the dual reasons of Jay Rayner having finally discovered their xiao long bao and writing about them in tones that made me crave them from when I used to do them regularly and a strong desire to avoid a particular client meeting I don't want to be in, let's have dim sum tomorrow - it's been ages! (Opposite De Hems) Leong's Legends, 4 Macclesfield st W1D 6AX James Sent from my iPhone
Re: London.pm Dim Sum, Leong's Legends, Thursday 12th September 13:00
13:00, as per subject? :) /j Sent from my iPhone On 11 Sep 2013, at 20:44, Gordon Banner t...@gordonbanner.me.uk wrote: Any particular time? On 11/09/2013 06:52, James Laver wrote: Motivated by the dual reasons of Jay Rayner having finally discovered their xiao long bao and writing about them in tones that made me crave them from when I used to do them regularly and a strong desire to avoid a particular client meeting I don't want to be in, let's have dim sum tomorrow - it's been ages! (Opposite De Hems) Leong's Legends, 4 Macclesfield st W1D 6AX James Sent from my iPhone
Re: Assigning Classes
Sent from my iPhone On 10 Sep 2013, at 08:50, Raphael Mankin r...@mankin.org.uk wrote: This approach has exponential complexity. Definitely infeasible. Not necessarily. How many courses are there Dave? James
Re: Assigning Classes
On Tue, Sep 10, 2013 at 9:19 AM, Dave Cross d...@dave.org.uk wrote: Not necessarily. How many courses are there Dave? About 30. Sorry, that was in the original email. I meant to ask how many students. James
Re: Assigning Classes
On Tue, Sep 10, 2013 at 11:27 AM, Philippe Bruhat (BooK) philippe.bru...@free.fr wrote: OTOH, it might improve the network connectivity. And valuable (IRL) social networking opportunities. James
Re: Assigning Classes
On Mon, Sep 9, 2013 at 2:57 PM, Paul Johnson p...@pjcj.net wrote: On Mon, Sep 09, 2013 at 01:30:00PM +, Dave Hodgkinson wrote: Prolog. Facts and rules then go solve. no Actually, Prolog was my first thought too. The major limitation is fallback behaviour. James
Re: Assigning Classes
On Mon, Sep 9, 2013 at 4:10 PM, Dave Cross d...@dave.org.uk wrote: I'm pretty sure that Paul wasn't actually dismissing Prolog. I think you'll find he was making a joke. ...which I should have gotten but I'm full of cold. James
Re: Perl 5.16 vs Ruby 2.0 UTF-8 support
On Fri, Aug 23, 2013 at 5:37 PM, Nic Gibson n...@corbas.co.uk wrote: If you are seeing this in your then your code is either a) not encoded as ASCII (probably Latin-1 or UTF-8) or b) broken If you're seeing this in client-provided CSV, I recommend running a mile. Notes from the recent frontiers: - Excel windows exports as wincp1252 with \r\n line endings - Excel mac exports as macroman (yes, in 2013!) with \r line endings - UTF-8 is a great interchange format. But it's quite annoying perl doesn't have a flag to automatically en/decode to/from UTF-8 as regards STDIN and STDOUT (and in the case of STDIN, probably anything that uses) - iconv is awesome! Here are some handy aliases: alias utf8tolatin1=iconv -f utf-8 -t iso-8859-1 alias win1252toutf8=iconv -f windows-1252 -t utf-8 alias utf8towin1252=iconv -f utf-8 -t windows-1252 (a rather grumpy) James (who is sat on a client site at this hour thanks to aforementioned CSV)
Re: Perl 5.16 vs Ruby 2.0 UTF-8 support
On Fri, Aug 23, 2013 at 8:01 PM, Matt Lawrence matt.lawre...@virgin.net wrote: Doesn't the -C switch count? Or indeed the PERL_UNICODE environment variable. Matt I take it back. Wish I'd known about this 2 days ago, of course.
Re: Using grep on undefined array
On Wed, Aug 14, 2013 at 1:59 PM, Matt Lawrence matt.lawre...@virgin.net wrote:
man perlglossary:
autovivification
A Graeco-Roman word meaning “to bring oneself to life”. In Perl, storage
locations (lvalues) spontaneously generate themselves as needed, including
the creation of any hard reference values to point to the next level of
storage. The assignment $a[5][5][5][5][5] = quintet potentially creates
five scalar storage locations, plus four references (in the first four
scalar locations) pointing to four new anonymous arrays (to hold the last
four scalar locations). But the point of autovivification is that you don’t
have to worry about it.
perlglossary is wrong. It doesn't only occur as an lvalue but can
occur by access as well.
I'm actually surprised that noone has mentioned the 'autovivification'
pragma ('unpragma'?) by now in a fairly long thread.
use strict;
use warnings;
no autovivification;
my %foo;
my $bar = $foo{bar}[1];
die(fail 1) if %foo; # does not die because autovivification was suppress
use autovivification;
$bar = $foo{bar}[1];
die(fail 2) if %foo; # does die, we turned off suppression
James
Re: Assigning anonymous hash to a list
On 30 Jul 2013, at 22:32, Joseph Werner telco...@gmail.com wrote: No, What you have done here is to assigned a list value to an array of assignable elements. I am talking about the example at the top of this thread, which was a scalar assignment to a list of elements. You've seen what perl thinks of it (in the form of opcodes executed) and it isn't what you think it thinks. Please stop telling people it's raining when you're standing dry in the sunshine. Abigail is…Abigail. He's usually right. James
Re: Another Comparison Of Programming Languages
On Thu, Jul 11, 2013 at 2:49 PM, Raphael Mankin r...@mankin.org.uk wrote: His analysis of English, his native tongue, is considerably worse than his comparison of programming languages. I wouldn't bother trying to fix the article. Considering that aside from the perl entry being really quite wrong, the methodology is serious flawed, I can't imagine anyone taking it seriously. James
Re: New pet keeping rules in the Netherlands
On 20 Jun 2013, at 22:50, Kieren Diment dim...@gmail.com wrote: I particularly like it when they have babies and there are hundreds of tiny cute huntsman spiders all over the ceiling. For a bonus, they eat cockroaches. There was an old lady who swallowed a fly. Wait, what eats huntsmans again? James
Re: New pet keeping rules in the Netherlands
On 19 Jun 2013, at 22:14, Damian Conway dam...@conway.org wrote: Except that it's a species of Australian wildlife. And nocturnal. Which means that it will wait until you fall asleep before it kills you. Skippy, skippy, skippy the bush kangaroo-oo James
Re: Living with smart match breakage
On 14 Jun 2013, at 10:26, Kieren Diment dim...@gmail.com wrote: [1] Not that I use many of the newer core features, occasionally I have to account for some of my $work code having to work on 5.8. I don't use smart match precisely because it doesn't feel intuitive and I have enough to worry about without having to memorise yet another table of results, some of which are surprising. I suspect most people are in the same boat, but the darkpan argument always gets trotted out in these cases. The solution you present of a Perl release that fails compile would be nice though. Perhaps with a switch in a new release of Perl? James
Re: Scope of variables in a function
On 2 Jun 2013, at 12:42, Dave Mitchell da...@iabyn.com wrote:
I'm not aware of any particular performance penalty:
$ time perl5180o -E'for (1..100_000_000) { my $x = 1 }'
real 0m5.638s
$ time perl5180o -E'for (1..100_000_000) { my $x }'
real 0m4.012s
$ time perl5180o -E'for (1..100_000_000) { state $x = 1 }'
real 0m3.060s
$ time perl5180o -E'my $x; for (1..100_000_000) { $x }'
real 0m2.787s
Yes technically its slightly slower than a bare '$x', but it's a lot
faster than a bare 'my $x';
I stand corrected. I thought I'd seen a warning in the docs at some point but
evidently I'm making it up.
/j
Re: Scope of variables in a function
On 1 Jun 2013, at 18:23, Dirk Koopman d...@tobit.co.uk wrote: It is very annoying. The more so because this is an artefact that is (apparently) relied on by a lot of legacy code. Quite a lot of other perl artefacts have been deprecated and then removed. Why does this one persist? In what way is it useful or intuitive? We did formalise an alternative, in the form of :state, but I don't know about how well it's used. It also incurs a performance penalty that people are presumably unhappy about (but then one assumes it's also incurred by the informal version too…) /j
Re: npm, PyPi overtake CPAN
On 24 May 2013, at 01:31, Paul Makepeace pa...@paulm.com wrote: I'm sure there's plenty of caveats etc but the gradients is probably what's most interesting here; CPAN is relatively static compared with, well, all the others. How about the caveat of utility? Whilst npm has a reasonable SNR and gems has so many modules that there are enough useful ones hidden there, pypi is mostly full of crap and not useful when you want to achieve something. That said, egg basket makes it remarkably easy to host your own mini-pypi server for darkpan you've generated
Re: Random Perl Content
On 19 May 2013, at 07:29, Matthew Seaman m.sea...@infracaninophile.co.uk wrote: Why not just write each of your streams of random numbers to a file and then just re-read the file when you need to reuse that sequence? That involves quite a lot more careful management. The approach of logging seeds is quite widely used. In fact MySQL replication sends out the seed in each replica because they do it ass backwards and forgot someone night actually embed random() in their query. James
Re: Alternative sources of Perl programmers
On 17 May 2013, at 20:28, Duncan Garland duncan.garl...@ntlworld.com wrote:
Do you want to come out to Thames Ditton? It's a bit of a hike, but if
you're interested I'll see what I can do.
Historically, London.pm events outside of vaguely central london tend to have
poor attendance ('vaguely' here means the BBC and Net-A-Porter are both easy to
get to despite being in zone 2). I think Thames Ditton might be stretching the
definition of 'vaguely central london' a little too far, but thanks for the
offer.
James
Re: June social poll
On 16 May 2013, at 17:07, Peter Corlett ab...@cabal.org.uk wrote: Hi, So, may I have your input into whether we should: a) do the beer festival at the Gunmakers; b) go to one of our other favourite haunts such as the Bridge House, Founders Arms, or the Edgar Wallace; or c) try somewhere entirely new? Whilst option 'c' is entirely appealing, you forgot option 'awesome': have beer somewhere else followed by an ultra-heretical beer festival meet the following night. /j
Re: Alternative sources of Perl programmers
On 15 May 2013, at 23:04, Tom Hukins t...@eborcom.com wrote: I'm pleased that you enjoy your involvement in our community, but please don't spread the rumour that anything we used to do stopped happening. With a small group of volunteers and a large group of followers and mailing list subscribers, reality sometimes disrupts our aspirations. Indeed, I've been volunteered to organise the next tech meet. Now if we could just find a venue… James
Re: Number::Fraction
On 6 May 2013, at 13:57, Th. J. van Hoesel th.j.v.hoe...@gmail.com wrote:
What if people figured out that the method did accept 3 or more arguments
(why and how.. because they dug into the code ?). It would make no sensense
at all to call the method Number::Fraction-new( 1, 4, 6, 7, 2), but it would
produce by some magic allowance that it should return a Number::Fraction
object.
Okay, well first of all any constructor is going to take an arbitrary number of
arguments. That's how argument passing in perl works. If they read the code
they would see what it does, the only way they would otherwise see it taking
more than two arguments is by attempting to pass them. And if they did that,
they ought to have been reading the documentation more closely. Otherwise they
did and they just decided to see what happens? I don't see that one myself.
So, now we have some legacy code. And now extending the functionality in a
natural understandable manner, might cause old programs that did very odd
method calls to break.
I think you misunderstand here. How is what you propose a natural
understandable manner? Positional parameters are by convention added to the end
if you're creating more of them, not the front. See what messes libraries in
other languages have gotten into by making that mistake (erlang springs to
mind).
Furthermore, if programs are using the module aside from how it's documented,
they deserve to be broken. They could have submitted a bug to make something
official behaviour, but they didn't. And since we're talking about a simple
fraction module here, I don't think we're going to find anyone doing something
daft.
Is my next approach acceptable:
now:
a quick patch that will issue a warning the moment the method is being called
with 3 or more arguments (only once per application run), letting users know
that they did some odd thing, but forgive them and continue.
Nondestructive. I don't think anyone would argue with this.
next:
implement a 3-argument methode that will only work properly when the modules
is being used as
use Number::Fraction qw{:mixed}
still issue a warning
Why don't you just create a new constructor that takes arguments differently?
This would seem to be a good way around it. Seems to me you're way
overcomplicating things. It's also a common perl pattern because we're blessed
with the ability to have as many constructors as we want.
next:
let the module die with unintended 3-plus-argument calls
use Number::Fraction qw{:mixed}
Again, you're overcomplicating.
next:
drop the requirement to use :mixed, make it default
all in a time frame of one year ?
Why on earth are you overcomplicating this so?
Someone really need to enlighten me as to why write method implementations
like this, that accept arbitrary arguments, rather than locking down the API
It's a dynamic language. We have documentation on how to do things. And extra
arguments are ignored. This is fairly normal. I write a lot of code that does
this too and i don't consider it broken. In fact, it's more or less a perl
idiom and common to a lot of dynamic languages really (though in the majority
of cases they just use named parameters because the language has native support
for method signatures).
Ask yourself what you're achieving by changing the API like this. I think
you've got the potential to break code and I don't think you're doing it for
the right reasons. I don't like changing the order of positional parameters
when you're adding new ones either because it confuses people.
Furthermore, I don't think what Dave is suggesting about the move to Moose is a
daft one, but you'd do well to preserve the API as it currently stands. Perhaps
a BUILDARGS method that checks if it's being called according to the old API
(i.e. has two args, both of which are numeric) and fills in the keys for you if
so? To get the new 'mixed' functionality, you'd just pass in the keys manually
and it would do the right thing?
James
Re: Number::Fraction
Jesus, I thought my mail was long…
Apols in advance...
On 6 May 2013, at 21:13, Th. J. van Hoesel th.j.v.hoe...@gmail.com wrote:
After reading it three times, I have a slight feeling that I have bitten of
more then I can chew... and it was such a small bite already, couldn't find a
smaller module, so little code and such a elegant way of doing what it is
supposed to do - and I have some kind of affinity with as former math-teacher.
It is a fairly trivial module and I don't think wrong for your first chunk of
real world perl to be honest, I just think perhaps a little guidance could help.
And the documentation does say what parameters it takes, does not say
anything about what it does when passing in additional things.
Well then, it's undocumented behaviour, which should not be relied upon. I
don't personally see any harm in being liberal in what you accept.
I will admit, working with positional parameters is bad, and I do acknowledge
the danger in just adding other parameters and mess up the thing. Particular,
like stated before, Perl takes any number of parameters in function-calls,
and it would not be fun to have to reorder the parameters in the function
call anytime someone comes up with a new idea.
Well quite.
But it doesn't --- or, I have not tested it, but the code does explain. It
happily keeps running, though it is not conform the documentation
Sorry, how does it not conform to the documentation exactly? My understanding
here was that it didn't document what it did with extra params and thus a
fairly reasonable response was to simply ignore them?
So, I should fill in an official bug ?
I remain unconvinced there is a bug. Unless you've tickled one with some code
you've got in production, I don't think a bug is worth filing.
Adding
if ( @_ 2 ) warn fractions consist of a numerator and a denominator, found
more than 2 parameters\n;
would be acceptable?
It seems like a reasonable position to me. A warning never hurts anyone who
isn't doing stupid things with %SIG.
Why don't you just create a new constructor that takes arguments
differently? This would seem to be a good way around it. Seems to me you're
way overcomplicating things. It's also a common perl pattern because we're
blessed with the ability to have as many constructors as we want.
that could be an option.
I'd like to keep the module as it is... but accept other arguments, atop of
what has already been implemented. The module accepts in one single method 3
different calls:
passing a reference, which clones it to a new object.
passing a string, which will be unraffled in a numerator and denominator.
passing in 2 integers to construct the object.
these are not 3 separate constructors.
I would like expand the string handling and allow it to pass in a string in
the form off a b/c. That is not a great deal, just a bit off code. However,
I think it then looks a bit off to need an additional routine
Number::Fraction-new_from_integer_numerator_and_denominator( a, b, c ).
Therefor, I'd like to be able to use the same constructor that works with 2
AND 3 parameters, I think that would look better, building on top off the
overload features.
It's not my module, I've never used it before and I personally couldn't care
less if you make it accept three params optionally and break code where people
aren't following the docs. But don't shove the new argument on the front
because it's a terrible thing to do. Also, I'd hardly see
next:
let the module die with unintended 3-plus-argument calls
use Number::Fraction qw{:mixed}
Again, you're overcomplicating.
May i quote: Furthermore, if programs are using the module aside from how
it's documented, they deserve to be broken.
You've well over-engineered this. Break things for the right reason, not
because you've got a batshit crazy way of solving a problem.
I'm only trying to phase out the undocumented possibility that the method
could be called with to many parameters, that would potentially cause harm
the moment you would reorder the arguments in the call.
I am aware of the danger now.
Had it been caught since the early releases, there might not had been any
calling programs that would do ...new-( 2, 5, 7);
Why is this a problem? Why can't you just work around it like everyone else
does?
Frankly have you considered making a subclass that handles three args? It might
be a better fit.
Doing Objective-C as well - which is not just a new kid in town either - that
does not use named parameters either, it does positional parameters to their
method calls. However, through some smart signature, it uses extreme long
function-calls that makes it all quite explicit and does do quite a lot of
parameter checking in the IDE. Guess the only way to do real named parameters
is through NSDictionary or what we in Perl have, called a hash, in which case
the order does not affect the result.
Re: Number::Fraction
On 2 May 2013, at 18:50, Th. J. van Hoesel th.j.v.hoe...@gmail.com wrote: Back to your code, line 198: if (@_ = 2) Why not check for if (@_ == 2) ? it should have only two arguments to construct a fraction from calling Number::Fraction-new(1, 2); Why would you allow it to pass other arguments? It looks like a combination of defensive programming and laziness. If you check for length of two, you have to handle both the case of too few args and too many args in addition to the case of two args. This is lazier and will it really harm it people pass more than 2 to silently ignore the extras? James
Re: Best Practices for passing option hashes into XS
On 28 Apr 2013, at 01:55, Simon Wistow si...@thegestalt.org wrote:
and then pass the HV into some C code. But I dislike having Perl types
in otherwise Perl free code.
snip
So my second thought is to have a struct
typedef struct {
char* first_opt;
char* second_opt;
} foo_struct;
I think you've basically got a first question you haven't asked. Are you
writing a C library that you want to interface with in perl or are you writing
an XS library? If the former, you should probably translate them into a broader
structure that includes all of the options you're looking for (or pass them as
plain parameters into the remainder of the code). If the latter, you should
stick with Perl datatypes.
James
Re: Best Practices for passing option hashes into XS
On 28 Apr 2013, at 16:33, Simon Wistow si...@thegestalt.org wrote: Firstly, while technically the C code written for the module is never used anywhere else. However I didn't write it originally - I'm merely patching it - and it currently doesn't use any Perl datatypes anywhere else so I'm loathe to add Perl datatypes for that reason. That sounds awfully like a compatibility shim for perl. Where using Perl datatypes would be appropriate. Secondly, I have also, several times in the past, wanted to appropriate C code I've written or observed in Perl modules (also Ruby, PHP and Python extensions) and use them elsewhere and the use of Perl Datatypes prevents that. Ultimately you still need some sort of shim. Sounds like you're actually writing a reasonable amount of C and that it would be better off being a C library in and of itself. Lastly, an aesthetic choice. The language Perl is written in is technically C but really, it's not. It is great for writing Perl but it's not what you'd call pretty or easily accessible. Moreover it *looks* different to 'regular' C. The code I'm modifying is written in nice (to my eyes) lower_case C dialect. The code I'm adding is OpenSSL Camel_case and the juxtaposition makes me wince. Adding in a third style might be too much to bear. But it has to go somewhere. You still need shim code somewhere. If I was going to add a fourth (less well thought out) reason it would be that, like dates and string encodings, one should get ones data into a canonical form as close to the 'edge' as possible. In this case all my XS and Perl code is in the .xs file and all the C is in .c file and never the twain shall meet. I suppose this is just the second point again. Again, I think it comes down to that question. It sounds like you're writing a C library and a perl shim in the same chunk of code. You should think about separating them. James
Re: Raising Perl awareness on Tiobe + Wikipedia, etc.
On 21 Mar 2013, at 08:08, Mallory van Achterberg stommep...@stommepoes.nl wrote: However Javascript, while starting out lacking a lot, today has filled in many of the gaps. It never fixed its basic retardation, but libraries exist to fix it. JavaScript is an implementation detail of jQuery*. If something similar existed to make non-DOM JS less painful, perhaps I wouldn't despise node.js so much. /j * oh of course I have a list of rants about jQuery, glad you asked. Let's start with position:relative being assumed when you do .show(). Among *many* others. Wow, it really is like perl.
Re: jQuery
On 21 Mar 2013, at 12:04, Ben Evans benjamin.john.ev...@gmail.com wrote: You should also get a copy of Javascript - The Good Parts by Douglas Crockford. Yes and no. Crockford has some interesting opinions. Particularly when it comes to what makes good quality javascript (jslint is fundamentally broken IMO). My guys seem to like Angular.js as well. AngularJS has the bizarre glory of daftest release names i've ever seen: https://en.wikipedia.org/wiki/AngularJS#Releases /j
Re: Raising Perl awareness on Tiobe + Wikipedia, etc.
On 20 Mar 2013, at 08:47, Greg McCarroll g...@mccarroll.org.uk wrote: Now throw in node.js and recently you could build another argument for the importance of JS. Someone didn't see my talk at LPW.* I think the hype will blow over eventually because people will figure out that cooperative multitasking makes things like bcrypt remarkably hard. Not to mention that it's very irritating to program node. And don't get me started again, I already gave them damn talk. James * The one where I didn't spend the entire time being heckled by people who've been programming perl since the 0.1 release. The one where I had the audience chanting web scale at me. Such fun.
Re: New perl features?
On 15 Mar 2013, at 13:04, DAVID HODGKINSON daveh...@gmail.com wrote: So, no then. In the sense of having a single page of good examples of using the new features. With so many orgs stuck on ancient perls, it may not be a full solution. Sure it may attract newbies but if they get a job with an ancient perl they're going to be disappointed they can't use all that shiny. James
London.pm Dim Sum, Canary Wharf, Thursday 14th March 1pm
It's been a bloody long while since I summed dims, dimmed sums or ate delicious dumplings. Given that I spend far too much of my time around Canary Wharf, I miss most of the list-organised ones. Accordingly, it's time I stopped being lazy and organised one. We did this one a very long time ago and I seem to recall we had a little difficulty getting seated, so if you know in advance you want to attend, please email off list; the fewer ransomers we have on the day, the higher our chances. Royal China, 30 Westferry Circus, London E14 8RR 1PM. Be there or be hungry :) Cheers, James
Re: cpan you have to see
On 12 Dec 2012, at 15:57, Uri Guttman u...@stemsystems.com wrote: On 12/12/2012 07:12 AM, Leon Brocard wrote: he still thinks his code is doing something useful It is. I had to write something similar to his Boolean module when I inherited a fucked up database that had different standards for Boolean values in different parts of the code base. Everything was stored in a blob column for extra meta-database hate. Just because you get to work with all of the nice clean code in the world doesn't mean some people aren't stuck with the mistakes of others. Then again, my primary income stream is writing code and yours is recruitment, so it's expected I'm more likely to have to clean up messes. /j
Re: Agents part CCXXXIV
On 3 Dec 2012, at 06:38, Uri Guttman u...@stemsystems.com wrote: one reason i ask my candidates where else they are being submitted is to avoid those duplications. Bullshit. You ask because you want to try and muscle in on those positions. If you really asked permission before submitting every time (as you claim later in your email) you'd never be in a position of double submission. Pimp standard trick #4. /j
Re: Agents part CCXXXIV
On 2 Dec 2012, at 20:32, Dave Hodgkinson daveh...@gmail.com wrote: If an agent sends your resume somewhere without telling you, is there any kind of redress? Legally they broke the DPA. Good luck doing anything about it. /j
Re: Perl outreach
On 29 Nov 2012, at 12:33, gvim gvi...@gmail.com wrote: If we want to be Perl noticed again as a serious contender for new projects I'd say our best bet is to finally get Perl 6 finished, or at least production-ready. I know Perl 5 is excellent but Perl needs something new to get noticed again. That something is Perl 6. Perl == Perl 5. I fail to see how replacing it with another language helps the language being replaced. Fact is noone really cares how supposedly amazing a language is if there isn't a huge collection of pre-written code you can use with it. As anyone who saw my talk about other techs at LPW will know, I've been writing clojure of late. Unlike perl6, I can tap into a huge body of pre-written java code which goes some way to stopping me missing cpan. And don't even think cp6an is enough. /j
Re: Perl outreach
On 27 Nov 2012, at 12:51, Edmund von der Burg e...@ecclestoad.co.uk wrote: but I'm now a Node fan boy. The asynchronous approach tickles me. And npm is GLORIOUS. Does this mean that others will like Node - not at all. Try 'em all! And in one of my talks at LPW I went into length about why I can't stand node.js. Actually that's not true: I like synchronous node.js, just everything goes to pot if you want async. Wanting to play with new things is how I wound up on clojure. /j
Re: Perl outreach
On 27 Nov 2012, at 13:10, Bob Walker b...@randomness.org.uk wrote: On Tue, 27 Nov 2012, Edmund von der Burg wrote: And npm is GLORIOUS. I cant quite decide if the fact that it installs a module's dependencies in the directory of the module you're installing is insane or a very good idea. I like this. I note that both sbt (scala) and leiningen (clojure) do this also. I presume it's a java standard thing. Normally it dumps a jar in there of course. /j -- Sent from my invisible pink unicorn
Re: Perl outreach
On 27 Nov 2012, at 14:20, Edmund von der Burg e...@ecclestoad.co.uk wrote: To be sure there are some thing that async is awful at. I love it for APIs and responding to web requests. Anything short and sweet and potentially blocking or concurrent. For building a moderately complex REST API I found it tedious in the extreme. I'm currently building it in Perl with a view to replacing it with clojure past the prototype stage. Frankly if it weren't for the fact some parts of it require functionality for which the perl libraries are shit, I would keep it in perl and I'm far too lazy to bite off even more projects than the ones I currently have going. I do not believe there is a better prototype language than perl unless your vision happens to fit precisely into the typical app model of something like rails (and mine really does not). Not that perl is only capable of prototypes, merely that my app has special needs on the macro scale and I'm lazy. Oh, on the topic of node, I like npm. Npm feels like a JavaScript port of something written in perl. For the sequential testing of clicking on a web interface it was painful to the extreme. To the extent that I threw away all that code and started again using watir (http://watirwebdriver.com/). Which is Ruby. Who cares, it works! I would reach for cucumber/capybara in that situation. Watir is nice but cucumber grew on me after a while. /j -- Sent from my invisible pink unicorn
Re: London Perl Conference 2012 photos
On 25 Nov 2012, at 16:04, Chris Jack (MSN) chris_j...@msn.com wrote: https://picasaweb.google.com/104598318166622233830/LondonPerlConference24112 012?authuser=0feat=directlink https://picasaweb.google.com/104598318166622233830/LondonPerlConference24112012?authuser=0feat=directlink#5814779230205261074 Not entirely flattering. You must have picked a hell of a moment. /j
Re: 25 Years of Perl
On 24 Nov 2012, at 00:36, Uri Guttman u...@stemsystems.com wrote: this thread reminds me of something we need to crow about more. so many conventions, inventions, ideas have come from the perl community and then be copied/stolen/absorbed by other langs, usually without much recognition. We do of course do the same thing back when the ideas are worth stealing. TAP is used everywhere now. perl invented and spread it so it is universal in the perl world. TAP can be used certainly, but most languages have their own testing infrastructure. Most of it is pretty crap to be honest, but TAP is certainly not the only game in town. When dealing with Jenkins, for example, we have to use the JUnit harness because JUnit output is all that it understands. cpan is always being copied (poorly) by other langs. they just never get the community feeling of uploading to cpan as a cred and for sharing. The actual repository, yes. The clients, well personally I think Leiningen (clojure) does a better job. Now if they could work on reducing the output like Minicpan did... yapc has yet to be properly copied. no one else delivers more bang for the buck and fun as well. mjd invented lightning talks and they are at many confs now, not just lang ones. another perl invention with no credit given. How are these perl inventions? They are community inventions. /j
Re: 25 Years of Perl
On 22 Nov 2012, at 12:19, Abigail abig...@abigail.be wrote: A community thing that hasn't been mentioned yet: conference auctions. (Isn't London.pm still suffering from the outcome of an auction in 2001?) I consider it an interesting quirk. Interestingly the PHP and python meetups in london all pick the first thursday of the month, so if one were so inclined, one months where the first thursday after the first wednesday of the month comes out to mean the 8th, if one were to miss the orthodox social, one could attend the group for another language and the heretical social in one month. I, of course choose to attend the orthodox social where possible. /j
Re: 25 Years of Perl
On 20 Nov 2012, at 09:09, Jacqui Caren jacqui.ca...@ntlworld.com wrote: I know Tim will not blow his own trumpet but ... One of the biggies was and is DBI. We take it so much for granted that you could connect to any number of different database engines with the same perl binary these days, or with any other programming language too, but really perl led the world here. This was quietly revolutionary. How many webhosts do we think would ship several perls for several different database engines? /j
Re: I love git
On Sun, Oct 28, 2012 at 12:06 PM, David Cantrell da...@cantrell.org.uk wrote: Lovely. Now, having deleted the branch on one machine, and pushed the delete to github, how do I make it disappear everywhere else that I've got a copy of the repo? git push origin :branchname # note the significant colon Assuming your remote for github is 'origin'. You can also specify another branch to the left of the colon (e.g. foo:bar to push local branch foo to remote branch bar) /j
