exercism/elixir/wine-cellar/lib/wine_cellar.ex

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1.4 KiB
Elixir

defmodule WineCellar do
@colors [
white: "Fermented without skin contact.",
red: "Fermented with skin contact using dark-colored grapes.",
rose: "Fermented with some skin contact, but not enough to qualify as a red wine."
]
# @cellar [
# white: {"Chardonnay", 2015, "Italy"},
# white: {"Pinot grigio", 2017, "Germany"},
# red: {"Pinot noir", 2016, "France"},
# rose: {"Dornfelder", 2018, "Germany"}
# ]
def explain_colors(), do: @colors
def filter(cellar, color, opts \\ []) do
cellar
|> Keyword.get_values(color)
|> filter_by_year(opts[:year])
|> filter_by_country(opts[:country])
end
# The functions below do not need to be modified.
defp filter_by_year(wines, year)
defp filter_by_year(wines, nil), do: wines
defp filter_by_year([], _year), do: []
defp filter_by_year([{_, year, _} = wine | tail], year) do
[wine | filter_by_year(tail, year)]
end
defp filter_by_year([{_, _, _} | tail], year) do
filter_by_year(tail, year)
end
defp filter_by_country(wines, country)
defp filter_by_country(wines, nil), do: wines
defp filter_by_country([], _country), do: []
defp filter_by_country([{_, _, country} = wine | tail], country) do
[wine | filter_by_country(tail, country)]
end
defp filter_by_country([{_, _, _} | tail], country) do
filter_by_country(tail, country)
end
end