While working on a research tool for my work I have noticed that my ruby solution rounds differently then the original c# .net code. It was not in every but about 10 percent of my tests failed due to the different rounding schemes.

Ruby uses the Symmetric Arithmetic Rounding while C# .net uses the Gaussian rounding otherwise known as the Banker’s routing.

I have looked for a quick solution for Ruby but Google did not return a result I could immediately use. I have found a javascript solution which I translated to Ruby.

Additionally I have added a “decimal” parameter to specify the precision of rounding.

Here is the code:

class Numeric
  def _round(val)
    sign = val < 0 ? -1 : 1
    return (val.abs.round * sign) if (val.abs - val.abs.floor) != 0.5
    return (val.abs.ceil  * sign) if val.abs.floor % 2 == 1
    return (val.abs.floor * sign)
  end

  def gaussian_round(decimals = 0)
    return (_round(self * (10**decimals))/((10**decimals).to_f))
  end
end

I have been looking into automating some of my development tasks in Cocoa/Xcode environment.  For the longest time I was using Subversion which would integrate quite well with Xcode. Recently, however, I have been exploring other version control systems.  Especially git.  Since it’s a much newer (D)VCS it does not have as much integration into systems as subversion.

I have managed to find some interesting solutions to include Git version number in Xcode project however the only actual solutions I have found are written in languages I don’t care for anymore.  Yes I can program in them but why would I want to.

So here is a quick solution written in MacRuby.

#!/usr/local/bin/macruby

git_output = `git show --abbrev-commit`
commit_version = git_output.split("\n").grep(/^commit/).first
version = commit_version.gsub(/^commit\s+(.*)\.{3}/, "\\1")
if version
  list = NSMutableDictionary.dictionaryWithContentsOfFile("Info.plist")
  list["CFBundleVersion"] = version
  list.writeToFile('Info.plist', :atomically => true)
end

In my final solution I intend to have an output in following format:

major.minor.revision (build)

where the “build” is going to correspond with the git commit version
and the other parts will reflect the marketing version numbers.

“If you don’t know where to start, start from writing tests.”

Sometimes a little bit of automation goes a long way and other times it may be just wasted time. I have run into one of these situations recently when dealing with Xcode and trying to rename menu items from NewApplication to the Application Name.

For Example:

Quit NewApplication -> Quit TestApp

My first approach was to use Ruby open the MainMenu.xib and do a replacement. This technique may prove to be useful in the future when I have more command line tools for other tasks, but currently there is a much simpler way of dealing with renaming menu items.

1. Right click on MainMenu.nib and select “Open As” -> “Source Code File”

2. Press: “Command-F” to open find/replace dialog

3. Replace all NewApplication strings with desired application name.

That’s it