Proposal: add System.IO.hGetBufSome
http://hackage.haskell.org/trac/ghc/ticket/4046 I'd like to add the following function to `System.IO`, alongside `hGetBuf` and `hGetBufNonBlocking`: {{{ -- | 'hGetBufSome' @hdl buf count@ reads data from the handle @hdl@ -- into the buffer @buf@. If there is any data available to read, -- then 'hGetBufSome' returns it immediately; it only blocks if there -- is no data to be read. -- -- It returns the number of bytes actually read. This may be zero if -- EOF was reached before any data was read (or if @count@ is zero). -- -- 'hGetBufSome' never raises an EOF exception, instead it returns a value -- smaller than @count@. -- -- If the handle is a pipe or socket, and the writing end -- is closed, 'hGetBufSome' will behave as if EOF was reached. -- -- 'hGetBufSome' ignores the prevailing 'TextEncoding' and 'NewlineMode' -- on the 'Handle', and reads bytes directly. }}} We need it to properly fix #4041 and #3808. It corresponds more closely to the semantics of Unix `read()`, and I've found this to be the most useful low-level API for reading in practice. In the long term we'd like to provide a better binary I/O API, and we might even get around to doing that before 6.14.1, but if not we'll need this. Deadline: 2 weeks. Cheers, Simon
On Wed, May 5, 2010 at 12:18 PM, Simon Marlow
http://hackage.haskell.org/trac/ghc/ticket/4046
I'd like to add the following function to `System.IO`, alongside `hGetBuf` and `hGetBufNonBlocking`:
[...] +1 from me. I would expect this to be available from System.IO as it closely resembles the low-level UNIX call. The BSD socket API is definitely one of the better out there, if you squint the eyes and look through the haze of C.q -- J.
+1 from me as well
On 5 May 2010 11:18, Simon Marlow
http://hackage.haskell.org/trac/ghc/ticket/4046
I'd like to add the following function to `System.IO`, alongside `hGetBuf` and `hGetBufNonBlocking`:
{{{ -- | 'hGetBufSome' @hdl buf count@ reads data from the handle @hdl@ -- into the buffer @buf@. If there is any data available to read, -- then 'hGetBufSome' returns it immediately; it only blocks if there -- is no data to be read. -- -- It returns the number of bytes actually read. This may be zero if -- EOF was reached before any data was read (or if @count@ is zero). -- -- 'hGetBufSome' never raises an EOF exception, instead it returns a value -- smaller than @count@. -- -- If the handle is a pipe or socket, and the writing end -- is closed, 'hGetBufSome' will behave as if EOF was reached. -- -- 'hGetBufSome' ignores the prevailing 'TextEncoding' and 'NewlineMode' -- on the 'Handle', and reads bytes directly. }}}
We need it to properly fix #4041 and #3808. It corresponds more closely to the semantics of Unix `read()`, and I've found this to be the most useful low-level API for reading in practice.
In the long term we'd like to provide a better binary I/O API, and we might even get around to doing that before 6.14.1, but if not we'll need this.
Deadline: 2 weeks.
Cheers, Simon _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries
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participants (4)
-
Jesper Louis Andersen -
Malcolm Wallace -
Simon Marlow -
Thomas Schilling