Colors.rb – Functional programming in Ruby example

colors.rb

#!/usr/bin/env ruby

require 'paleta'

to_paleta = ->(color) { Paleta::Color.new(:hex, color) rescue nil }
to_div = ->(str) {
  "<div style='font-family: sans-serif; width: 5em; height: 3em;
               line-height: 3em; display: inline-block; text-align: center;
               margin: 0.25em; border-radius: 0.25em; padding: 1em;
               background: ##{str}'>
  ##{str}
  </div>"
}

File.open('colors.html', 'w') do |file|
  file.puts(
    ARGF
      .map(&:chomp)
      .map(& to_paleta)
      .compact
      .sort_by(&:hue)
      .map(&:hex)
      .uniq
      .map(& to_div)
  )
end

`open colors.html`