我编写了一个玩具库,它使用依赖类型来表示货币及其类型签名中的货币:
data Currency = CHF | EUR | PLN | USD
deriving stock (Bounded, Enum, Eq, Read, Show)
data CurrencyWitness (c :: Currency) where
CHFWitness :: CurrencyWitness CHF
EURWitness :: CurrencyWitness EUR
PLNWitness :: CurrencyWitness PLN
USDWitness :: CurrencyWitness USD
deriving stock instance Eq (CurrencyWitness c)
deriving stock instance Show (CurrencyWitness c)
data Money (currency :: Currency) representation = Money
{ moneyCurrency :: !(CurrencyWitness currency)
, moneyAmount :: !representation
}
deriving stock (Eq, Show)
add :: (Num r) => Money …
Run Code Online (Sandbox Code Playgroud) 我第一次获得 macOS 机器,我不知道如何使用alt+等命令E打开.$EDITOR
我不想将\xe2\x8c\x98密钥重新映射到alt系统范围,但我不知道如何在 Kitty 或 Fish 中重新映射。
\n为什么鱼绑定在 mac os 中不起作用?是一个相关问题,但那里的答案仅适用于 iTerm2。
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