gistfile1.rb

def _system(*args)
  system('echo', *args)
  system(*args)
end

class CreateDependenciesFilter < Nanoc3::Filter

  identifier :create_dependencies
  type       :binary

  def run(filename, params={})
    content = File.read(filename)
    content.scan(/^#include "([^"]+)"/) do |str|
      # Find item
      dependent_item = @items.find { |i| i[:filename] == str[0] }
      puts "*** #{item.inspect} depends on #{dependent_item.inspect}"

      # Notify
      Nanoc3::NotificationCenter.post(:visit_started, dependent_item)
      Nanoc3::NotificationCenter.post(:visit_ended,   dependent_item)

      # Raise unmet dependency error if item is not yet compiled
      any_uncompiled_rep = dependent_item.reps.find { |r| !r.compiled? }
      raise Nanoc3::Errors::UnmetDependency.new(any_uncompiled_rep) if any_uncompiled_rep
    end

    FileUtils.cp(filename, output_filename)
  end

end

class CompileFilter < Nanoc3::Filter

  identifier :compile
  type       :binary

  def run(filename, params={})
    _system('clang', '-x', 'c', '-c', '-arch', 'i386', '-I.', '-o', output_filename, filename)
  end

end

class LinkFilter < Nanoc3::Filter

  identifier :link
  type       :binary

  def run(filename, params={})
    filenames = *params[:files].map do |dependent_item|
      # Notify
      Nanoc3::NotificationCenter.post(:visit_started, dependent_item)
      Nanoc3::NotificationCenter.post(:visit_ended,   dependent_item)

      # Raise unmet dependency error if item is not yet compiled
      any_uncompiled_rep = dependent_item.reps.find { |r| !r.compiled? }
      raise Nanoc3::Errors::UnmetDependency.new(any_uncompiled_rep) if any_uncompiled_rep

      # Done
      dependent_item.reps[0].raw_path
    end
    _system('clang', '-arch', 'i386', '-o', output_filename, *filenames)
  end

end