paiza.ioでelixir その38

概要

paiza.ioでelixirやってみた。
cond,case,with使ってみた。

サンプルコード

{n, m} = {100, 150}
result =
	cond do
		n > 100 -> "n is big"
		m > 100 -> "m is bigger"
		true -> "n nor m is not so big"
	end
|> IO.inspect	
cond do
	 0 > 1 -> "No"
	 0 > 2 -> "Nope"
	 true	-> "fallback"
end
|> IO.inspect
case {1, 0, 3} do
    {1, x, 3} when x > 0 -> 
        "マッチする"
    {1, x, 3} -> 
        "マッチする"
    _ -> 
        "マッチしない"
end
|> IO.inspect
func = fn -> 
    "hello" 
end
result =
	case func.() do
		str when is_nil(str) -> 
		    "empty!"
		str when is_binary(str) and str == "hello" -> 
		    "yeah!"
		_ -> 
		    "oops!"
	end
|> IO.inspect
case {1, 2, 3} do
    {4, 5, 6} ->
	    "This clause won't match"
	{1, x, 3} ->
		"This will match and bind x to 2"
	_ ->
		"This will match any value"
end
|> IO.inspect
cond do
	1 + 1 == 3 ->
		"I will never be seen"
	2 * 5 == 12 ->
		"Me neither"
	true ->
		"But I will (this is essentially an else)"
end
|> IO.inspect
with {:ok, {int, _asdf}} <- Integer.parse("123asdf"), {:ok, datetime, _utc_offset} <- DateTime.from_iso8601("2021-10-27T12:00:00Z") do
	DateTime.add(datetime, int, :second)
else
	:error ->
		"couldn't parse integer string"
		{:error, :invalid_format} -> "couldn't parse date string"
	_ ->
		"this will never get hit because all errors are handled"
end
|> IO.inspect
try do
	throw(:hello)
catch
	message ->
		"Got #{message}."
after
	IO.puts("I'm the after clause.")
end

実行結果

"m is bigger"
"fallback"
"マッチする"
"yeah!"
"This will match and bind x to 2"
"But I will (this is essentially an else)"
"this will never get hit because all errors are handled"
I'm the after clause.

成果物

以上。