On Mon, Dec 23, 2002 at 09:05:00AM +0000, Glynn Clements wrote:
The main problems with lazy I/O are the lack of control over ordering (e.g. you can't delete the file until a stream has been closed, but you may not be able to control how long the stream remains open), and the inability to handle exceptions (the actual exception won't occur until after e.g. getContents has returned).
For my purposes it suffices to have a notion of when I'm done generating output from the input stream and I close the handle then. I basically just pass around the input file handles in perpetuity and either don't close them until the last minute, as it's important to clean up so I can reuse the action later, or until I'm done generating output from a complete scan of the thing. This forces the evaluation of the data structures created from the input, which may linger around longer than the input stream itself. Basically, I don't have these issues. Actually, you -should- be able to delete the file before the stream has been closed; this is a common idiom for dealing with temporary files. Bill