CAUTION: The begin <code> end while <condition> is rejected by Ruby’s author Matz. Instead he suggests using Kernel#loop, e.g. loop do # some code here break if <condition> end Here’s an email exchange in 23 Nov 2005 where Matz states: |> Don’t use it please. I’m regretting this feature, and I’d like to |> remove … Read more
:: is basically a namespace resolution operator. It allows you to access items in modules, or class-level items in classes. For example, say you had this setup: module SomeModule module InnerModule class MyClass CONSTANT = 4 end end end You could access CONSTANT from outside the module as SomeModule::InnerModule::MyClass::CONSTANT. It doesn’t affect instance methods defined … Read more
There are pieces to this answer that helped me get what I needed (easy multi-line concatenation WITHOUT extra whitespace), but since none of the actual answers had it, I’m compiling them here: str=”this is a multi-line string”\ ‘ using implicit concatenation’\ ‘ to prevent spare \n\’s’ => “this is a multi-line string using implicit concatenation … Read more
EDIT: It has been 9 years since I originally wrote this answer, and it deserves some cosmetic surgery to keep it current. You can see the last version before the edit here. You can’t call the overwritten method by name or keyword. That’s one of the many reasons why monkey patching should be avoided and … Read more
If you’re using ruby 1.8.7 or 1.9, you can use the fact that iterator methods like each_with_index, when called without a block, return an Enumerator object, which you can call Enumerable methods like map on. So you can do: arr.each_with_index.map { |x,i| [x, i+2] } In 1.8.6 you can do: require ‘enumerator’ arr.enum_for(:each_with_index).map { |x,i| … Read more
What’s the difference between “include” and “require” in Ruby? Answer: The include and require methods do very different things. The require method does what include does in most other programming languages: run another file. It also tracks what you’ve required in the past and won’t require the same file twice. To run another file without … Read more
rails destroy controller lalala rails destroy model yadayada rails destroy scaffold hohoho Rails 3.2 adds a new d shortcut to the command, so now you can write: rails d controller lalala rails d model yadayada rails d scaffold hohoho
It’s easy; just do the following: rvm implode or rm -rf ~/.rvm And don’t forget to remove the script calls in the following files: ~/.bashrc ~/.bash_profile ~/.profile And maybe others depending on whatever shell you’re using.
Update for 2022 from TrinitronX Fast-forward to 2021 and now Bundler docs [web archive] now say to commit the Gemfile.lock inside a gem… ¯_(ツ)_/¯ I guess it makes sense for developers and ease of use when starting on a project. However, now CI jobs need to be sure to remove any stray Gemfile.lock files to … Read more
It’s shorthand for tags.map(&:name.to_proc).join(‘ ‘) If foo is an object with a to_proc method, then you can pass it to a method as &foo, which will call foo.to_proc and use that as the method’s block. The Symbol#to_proc method was originally added by ActiveSupport but has been integrated into Ruby 1.8.7. This is its implementation: class … Read more