Spaces around all hyphens in a string without double-up
- by Dave
I'm after a regex that puts spaces around each "-" in a string, eg.
02 jaguar-leopard, tiger-panther 08
would become 
02 jaguar - leopard, tiger - panther 08
Note that if the "-" already has spaces around it, no changes are to be made, eg.
02 jaguar - leopard, tiger - panther 08
should not become 
02 jaguar  -  leopard, tiger  -  panther 08
The number of hyphens are unknown in advance. 
Thanks for any ideas...
Edit:
I'm not actually using a language for this. I'm using Ant Renamer (a mass file renaming utility). There are two fields in the renamer GUI, "Expression" and "New name" to provide inputs. This is from the help file as an example:
    Swapping artist and title from mp3 file names:
    "Expression" = (.*) - (.*)\.mp3 
    "New name" = $2 - $1.mp3 
    Extract episode number and title from series video files with episode number as SnnEmm     followed by title:
    "Expression" = Code\.Quantum\.S([0-9]{2})E([0-9]{2})\.(.*)\.FRENCH.XViD\.avi 
    "New name" = Code Quantum - $1$2 - $3.avi