uninstall-hs should check that system has greator version of GHC or not

[r0ml]

uninstall-hs works well if system has only Haskell Platform version or prior version of GHC. But if system has greator version of GHC, uninstall-hs causes undesirable result.

For example:

My system already has GHC 7.2.2, I installed Haskell Platform 2011.4.0.0 (GHC 7.0.4), and then I installed GHC HEAD's binary pkg for testing. After testing, I tried to remove GHC HEAD by using uninstall-hs. uninstall-hs removes /usr/bin/ghc and /usr/bin/cabal symbolic link accidently.

$ sudo uninstall-hs only 7.5.20111221 --remove
$ ghc -V-bash: /usr/bin/ghc: No such file or directory
$ cabal -V
cabal: unrecognised command: -v (try --help)

And uninsatll-hs can't parse GHC 7.4.1 RC 1's version.

$ sudo uninstall-hs only 7.4.0.20111219 --remove
*** couldn't parse version
Usage: uninstall-hs              -- find versions on system
       uninstall-hs thru VERSION -- remove VERSION and earlier
       uninstall-hs only VERSION -- remove only VERSION
       uninstall-hs all          -- remove all
NOTE: Commands are 'dry run' by default and don't actually delete.
Options (can appear anywhere):
  -v  --verbose       report each path
  -n  --dry-run       only report what would be removed
  -s  --sh, --script  generate a shell script to remove files
  -r  --rm, --remove  actually remove files
  -?  --help          help (this message)

Okay, /Library/Haskell/doc/start.html says that uninstall-hs can remove just current and prior version. But there is one more problem. My system was installed GHC 7.0.4, 7.2.2, and HEAD (7.5.20111221). So, if using GHC's uninstaller (/Library/Frameworks/GHC.framework/Versions//Tools/Uninstaller), /usr/bin/ghc is changes into GHC 7.2.2 instead of 7.0.4. This is undesirable result, too.

And same problem occur when uninstall-hs removes Haskell Platform's GHC 7.0.4 if system has greator version....

I think that uninstall-hs should check system has greator version of GHC or not in /Library/Frameworks/GHC.framework/Versions/ directory.