Proposal: overhaul System.Process

[Don Stewart]

duncan.coutts:
> 
> On Tue, 2008-04-22 at 15:52 -0700, Don Stewart wrote:
> > duncan.coutts:
> 
> > > > > I would have thought (ExitCode,String) was more appropriate.
> > > > 
> > > > Yes, definitely.
> > > 
> > > Yes, I mentioned this to Don previously when he published his popen
> > > code. I think he agreed.
> 
> > I'd changed, but not pushed out, process-light:
> 
> > readProcess :: FilePath                     -- ^ command to run
> >             -> [String]                     -- ^ any arguments
> >             -> String                       -- ^ standard input
> >             -> IO (Either (ExitCode,String) String)  -- ^ either the stdout, or an exitcode and any output
> 
> You don't need the Either. ExitCode already covers the case when the
> process terminates successfully.
> 

But we want to force people to check the failure case. Just returning
the tuple doesn't help there.

-- Don