Where is Network.Socket.ByteString.Lazy's sendTo?

问题

Both Network.Socket.ByteString and Network.Socket.ByteString.Lazy have a send function.

Network.Socket.ByteString has a sendTo function, but Network.Socket.ByteString.Lazy doesn't.

How can I use Network.Socket.ByteString's sendTo with a Lazy.ByteString or Network.Socket.ByteString.Lazy's send function. (i.e. how do I tell it where to send the packet.)

Can anyone recommend a good tutorial on Haskell's Strings, BytesStrings. Lazy.ByteStrings, etc. as I find them very confusing (coming from a Java/Python background).

回答1:

Note that sendTo is strict in the data sent, and so there's no real logic to passing it a lazy bytestring. That's why the function only exists on strict bytestrings.

回答2:

The answer was to make a new function:

import Data.ByteString as BS
import Data.ByteString.Lazy as LBS

lazyToStrictBS :: LBS.ByteString -> BS.ByteString
lazyToStrictBS x = BS.concat $ LBS.toChunks x

and use it to convert the Lazy.ByteString into a normal ByteString.

Here's the converse, so that I find it when I google this problem again in future.

import Data.ByteString as BS
import Data.ByteString.Lazy as LBS

strictToLazyBS :: BS.ByteString -> LBS.ByteString
strictToLazyBS x = LBS.fromChunks [x] 

来源：https://stackoverflow.com/questions/11052388/where-is-network-socket-bytestring-lazys-sendto