Programming Crystal

Documenting a Project

You do document your code, don’t you? Crystal makes that easy: it allows for easy docs in Markdown format. It has no special doc syntax apart from #, so all your comments are documentation. First, read through the guidelines.^[43] Now let’s add some doc comments to your mineral project (you did create the exercise, didn’t you?). Here’s an example:

managing_projects/mineral/src/mineral.cr

require "./mineral/*"

module Mineral
  puts "app mineral is started!"

module Hardness
  def data
    mohs = {"talc" => 1, "gold" => 2.5, "calcite" => 3,
            "apatite" => 5, "corundum" => 9}
  end

  def hardness
    data[self.name]
  end
end

# Every Mineral has **hardness** (see the `Hardness` module). ...