On Wed, Sep 17, 2008 at 04:51:07PM +0100, Mitchell, Neil wrote:
But since GHC does not implement such a function, I was curious to know why it don't even implement a function that make sure the temporary file is removed.
Because it is two lines to write, so no one has yet proposed it for the base library.
Map is 2 lines, but we have that as a library (1 line in Hugs). Otherwise is a whole one lexeme long, but we still provide a library function.
This one is tricky and has lots of edge cases! If its useful, it should be in the libraries.
In particular, the code Don quoted is incorrect depending on which import statements are used. If we assume that the default is the bracket available in Haskell 98, then it is definitely incorrect. It also doesn't behave properly in the presence of signals or keyboard interrupts (i.e. posix or windows systems). Of course, a larger change in the standard libraries is needed in order to solve this particular problem, so I'd want to agree on a solution for that problem first. Which is perhaps a better reason why it's not yet in the standard libraries: it's perhaps not a good idea to put a function with such serious issues into the standard libraries. David