mineral.cr

class Mineral
  getter name : String
  getter hardness : Float64
  getter crystal_struct : String

  def initialize(name, hardness, crystal_struct)
    @name = name
    @hardness = hardness
    @crystal_struct = crystal_struct
  end
end

def mineral_with_crystal_struct(crstruct, minerals)
  minerals.find{ |m| m.crystal_struct == crstruct }
end

def longest_name(minerals)
  minerals.map{ |m| m.name }.max_by{ |name| name.size }
end

minerals = [
  Mineral.new("gold", 1.0, "cubic"),
  Mineral.new("topaz", 8.0, "orthorombic"),
  Mineral.new("apatite", 5.0, "hexagonal"),
  Mineral.new("wolframite", 4.5, "monoclinic"),
  Mineral.new("calcite", 3.0, "trigonal"),
  Mineral.new("diamond", 10.0, "cubic"),
]

min = mineral_with_crystal_struct("hexagonal", minerals)
#min = mineral_with_crystal_struct("triclinic', minerals)
puts "#{min.crystal_struct} - #{min.name} - #{min.hardness}"

puts longest_name(minerals)