Posted by matijs
11/12/2011 at 18h08
Something weird just happened. While refactoring GirFFI, I had managed to remove all use of a particular module. So, I removed the corresponding file, ran the tests using
rake test
And the tests passed. Committed, done.
Then, I took a walk down to the library. By the time I got back, as soon as I looked at my code again, there it was: A giant require statement requiring the file I had just removed. Huh, why do my tests pass?
Well, duh, I have GirFFI installed as a gem, and my code is just picking up the missing file from there. So, I run
bundle exec rake test
The tests fail, showing me exactly the line I need to remove. Commit amended, done.
So, the moral of the story: If you’re developing a gem, use your isolation tool of choice, be it Bundler, Isolate, or something else, to shield your gem development environment from older installed versions.
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Posted by matijs
31/07/2011 at 17h31
Recently, there was a change in where Debian’s rubygems packages store each gem’s files. Instead of having a separate bin directory for each version of ruby, now both the 1.8 and the 1.9 version store scripts in /usr/local/bin. In fact, they will happily overwrite each other’s scripts. This can be very confusing when you think you’re running a script with Ruby 1.8, but in fact it’s running with 1.9, and hence, 1.9’s set of installed gems.
All this made me seriously consider using RVM. Which was quite shocking, as I consider it to be an ugly hack, both in concept and in execution. So, rather than admitting defeat, I decided to create my own hack.
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Posted by matijs
10/05/2011 at 07h09
Over two years ago, I had the idea, that it should be possible to combine two great technologies, ruby-ffi, and GObject Introspection, to dynamically create bindings for GLib-based libraries.
This idea, like many, was born from frustration: The development of
Ruby-GNOME2 is labour-intensive, and therefore, it lags behind the
development of Gnome libraries. In particular, I wanted to use the Gio
library, which had no bindings at the time, to fetch generated icons for
images.
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Posted by matijs
22/04/2011 at 09h30
Let’s look at dynamic method generation. I need it for GirFFI, and if you
do any kind of metaprogramming, you probably need it too. It was
already shown a long time ago that using string evaluation is preferable to using
define_method with a block.
That is, if you care at all about speed.
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Posted by matijs
13/12/2010 at 23h14
On twitter, @clemensk asks:
Hey SQL experts, is it somehow possible in pure (My)SQL to extract a
nested set from a table full of paths (think: Category 1 > Category 2)?
To do this, you need to do two things: Extract the names of the nodes, and
calculate values for lft and rgt. Here’s my take on the latter part:
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Posted by matijs
10/12/2010 at 09h29
If you’re going to do this:
def foo= f
@foo = f + " bar"
endThen don’t first do this:
But instead do this:
That way, there won’t be “method redefined” warnings all over the place.
Let’s make this more general: Before you release your gem, make sure it
runs without warnings. They should stick out like a sore thumb when you run
your tests, anyway.
Thanks.
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Posted by matijs
16/09/2010 at 17h22
If you still have commits with messages like ‘Oops, I forgot this file’, you’re doing something wrong. Just use git commit --amend.
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Posted by matijs
27/06/2010 at 21h10
In some of my Rails projects, I have been a contented user of the memory_test_fix plugin. However, I rather dislike the use of Rails plugins, because I find updating them later on rather difficult, and I don’t like including external libraries in my own source tree (hence, I don’t like the practice of vendoring gems much either). When the concept of ‘gem plugins’ was introduced, I created a fork on github and created the necessary files to build the plugin as a gem, and have Rails properly load it.
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Posted by matijs
15/04/2010 at 05h42
You can implement a programming language in assembly. C is an example. This
has the advantage of being able to leave your language and use assembly
when necessary. You drop down to assembly for speed.
You can also implement a programming language in lisp. CLPython is an
example. This has the advantage of being able to leave your language and
use lisp when necessary. You drop down to lisp for expressiveness.
If lisp is the ultimate language, does this not make it the best option for
implementing other languages?
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Posted by matijs
11/04/2010 at 12h22
Because URL shortening services can go away at any time, I decided
to install my own. In the spirit of your-own-dogfood, and to make hacking
it as enjoyable as possible, it had to be in Ruby (this ruled out
YOURLS, which otherwise does exactly what I want). There are tons
of URL shortening projects in Ruby on GitHub. Unfortunately, they all
lacked one feature: password protection for the adding of URLs. In the end,
I picked a nice simple one and changed it to my liking. The result can be
found in my fork of turl.
Why is this safer than using one of the existing services? The reason tr.im
went under is that they couldn't make it pay for itself, and there was a
lot of abuse from spammers. Both problems are absent for my own service: I
don't need to make any money off of it, and I'm the only one who can create
new short URLs.
Some observations on developing this software:
For a small project like this, putting everything in one file is very,
very nice. Ramaze allows you to do this (as do other frameworks),
Ruby on Rails does not. I wonder how seamless the transition is if
your project starts small like this and then gradually becomes big enough
that you need to split it into different files.
Ramaze's documentation needs some love. Everything is documented well in
principle, but with the split-off of the innate library, it took me
ages to find the documentation for the a method and friends.
I really like the idea of [Sequel][sq]::Model where you define the
table schema right in the model. I'm not sure how or how well it works
with migrations, but for a small project like this, it's nice and clean.
Ramaze could use some more options for session storage. In particular,
something file-based shouldn't be too much to ask for. I'm using the
LocalMemCache option, and keep having to log in.
I really like Ramaze, and am eager to try Sinatra. I have been
ignoring these more light-weight frameworks for far too long.
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