Posted by matijs
17/04/2012 at 07h41
This morning, I found myself looking for a simple markdown previewer that would run on the desktop. Using GirFFI, it was ridiculously easy to create it myself.
The simple version, based on the Webkit example in the GirFFI repository, goes something like this:
require 'ffi-gtk3'
require 'github/markup'
GirFFI.setup :WebKit, ’3.0’
Gtk.init
win = Gtk::Window.new :toplevel
scr = Gtk::ScrolledWindow.new nil, nil
wv = WebKit::WebView.new
win.add scr
scr.add wv
win.set_default_geometry 700, 500
win.show_all
file = ARGV[0]
fullpath = File.expand_path(file, Dir.pwd)
html = GitHub::Markup.render fullpath
wv.load_string html, nil, nil, "file://#{fullpath}"
GObject.signal_connect(win, "destroy") { Gtk.main_quit }
Gtk.main
I got the basic version working in about 10 minutes. The more complex version adds a keyboard handler to allow reloading the viewed file.
Tags
GirFFI, software
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Posted by matijs
19/02/2012 at 12h46
My list of all-time-favorite books for programmers. I’m not saying everyone should read these, but each of these had an important impact on my growth as a programmer. These are not necessarily in chronological order, by the way.
First, books that are mostly independent of your choice of programming language:
Design Patterns and Refactoring are not books to be read cover to cover, since they they devote quite a large part of their volume to catalogueing. The other two definitely are.
The following books are each really about a particular language. They’re well written, but it’s hard to separate the impact of the books from the impact of the languages.
-
Programming Perl (a.k.a. The Camel Book). This book made me grasp object-oriented programming for the first time by breaking it down to a very basic level. I did most of my learning Perl from this book.
-
Programming Ruby (a.k.a. The Pickaxe Book). I learned Ruby from the free online edition. It got me hooked.
Tags
books, life, programming
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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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software
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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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software
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Posted by matijs
30/06/2011 at 18h15
It’s happening, like it happens to all of us: My hard disk is getting full,
and although the free space would have seemed like an ocean just a decade
ago, now it’s a worryingly small pool of tiny little gigabytes. I could
try freeing up some by tediously going through all the photos I never
bothered to cull before, but with Gb-sized videos being added on a regular
basis, that isn’t a long term solution. Where long term is anything that
will tide me over to my next laptop.
But, what if I could offload some of those files to some other storage
medium? I’m not really that fond of external hard disks, but perhaps a file
server? Great! You mount some remote directory, and it’s like it’s right
there on your machine.
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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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software
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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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software
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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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software
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Posted by matijs
10/12/2010 at 09h29
If you’re going to do this:
<typo:code lang=“ruby”>
def foo= f
@foo = f + “ bar”
end
</typo:code>
Then don’t first do this:
<typo:code lang=“ruby”>
attr_accessor :foo
</typo:code>
But instead do this:
<typo:code lang=“ruby”>
attr_reader :foo
</typo:code>
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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software
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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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software
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