[Haskell-cafe] File path programme

[John Meacham]

On Wed, Jan 26, 2005 at 01:39:01PM -0000, Simon Marlow wrote:
> On 25 January 2005 19:45, Duncan Coutts wrote:
> 
> > On Tue, 2005-01-25 at 19:12 +0000, Ben Rudiak-Gould wrote:
> >> My concern here is that someone will actually use the library once it
> >> ships, with the following consequences:
> >> 
> >>     1. Programs using the library will have predictable
> >> (exploitable) bugs in pathname handling. 
> >> 
> >>     2. It will never be possible to change the current weird
> >> behavior, because it might break legacy code. The System.FilePath
> >> library will 
> >> have to remain in GHC forever in its current form, enticing
> >> programmers with its promise of easy pathname handling and then
> >> cruelly breaking its contract. 
> >> 
> >> If no one uses it in production code then we can fix it at our
> >> leisure, and having it out there with "experimental" status isn't
> >> necessarily a bad thing in that case. It just feels like we're
> >> playing a dangerous game. 
> > 
> > That's a sufficiently persuasive argument for me!
> > 
> > Could we just punt this library for this release. After all we can add
> > libraries in a later point release (eg 6.4.1) you just can't change
> > existing APIs.
> 
> We can't add libraries in a point release, because there's no way for
> code to use conditional compilation to test the patchlevel version
> number.
> 
> This seems to be a common misconception, probably brought about by the
> fact that the time between major releases of GHC is getting quite long.
> Perhaps I should stop writing email and get some work done :)


too bad we can't do things like

#if exists(module System.Path) 
import System.Path
#else
...
#endif

I still find it perplexing that there isn't a decent standard haskell
preprocessor.... 
        John

-- 
John Meacham - ⑆repetae.net⑆john⑈