getSpareBuffer :: Handle__ -> IO (BufferMode, CharBuffer)
getSpareBuffer Handle__{haCharBuffer=ref,
haBuffers=spare_ref,
haBufferMode=mode}
= do
case mode of
NoBuffering -> return (mode, error "no buffer!")
_ -> do
bufs <- readIORef spare_ref
buf <- readIORef ref
case bufs of
BufferListCons b rest -> do
writeIORef spare_ref rest
return (mode, emptyBuffer b (bufSize buf) WriteBuffer)
BufferListNil -> do
new_buf <- newCharBuffer (bufSize buf) WriteBuffer
return (mode, new_buf)
的代码是从GHC源代码。我想知道为什么这段代码的作者使用大括号代替参数。以及变量haCharBuffer,haBuffers,haBufferMode如何从ref,spare_ref和mode中获取值。这些值尚未定义。所述的CodeFile是GHC-7.4.1 \库\基\ GHC \ IO \拉手\ Text.hs
从GHC需要澄清的代码的另一种片段是这样的:
flushByteWriteBuffer :: Handle__ -> IO()
flushByteWriteBuffer [email protected]__{..} = do
bbuf <- readIORef haByteBuffer
when (not (isEmptyBuffer bbuf)) $ do
bbuf' <- Buffered.flushWriteBuffer haDevice bbuf
writeIORef haByteBuffer bbuf'
在的CodeFile ghc- 7.4.1 \ libraries \ base \ GHC \ IO \ Handle \ Internals.hs 大括号内是否使用了点?
感谢
因为我编辑了这个问题,你能回答第二部分关于带点内部大括号的大括号吗?谢谢 – Dragno 2012-07-21 14:01:09
请参阅我的编辑了解更多。 – dflemstr 2012-07-21 14:31:38
好的非常感谢。 – Dragno 2012-07-21 18:19:21