f# - 类似于 F# 中的 yield break

Question

如果先断后如何？

let WithdrawalCash (account, amount) = seq {        

    if ( account.Balance.CurrentAmount - amount < 0.0m) then
        yield NotEnoughMoneyForWithdrawal(account, amount)   
        // How to break here?     

    let newBalance = account.Balance.CurrentAmount - amount
    yield CashWithdrawnEvent(account, newBalance)
}

Answer 1

不确定这会有所帮助，为什么不使用 else 子句？

let WithdrawalCash (account, amount) = seq {        

   if ( account.Balance.CurrentAmount - amount < 0.0m) then
       yield NotEnoughMoneyForWithdrawal(account, amount)   
       // How to break here?     
   else 
      let newBalance = account.Balance.CurrentAmount - amount
      yield CashWithdrawnEvent(account, newBalance) 
}

也看看:
Imperative computation in F# (II.) - Writing break and continue