Global match and substitution for the regex engine would be great. That link leads to a thorough explanation of the concept by MrC. With that, I could maintain a single nested keywords field, tracking all kinds of data, then make calculated fields that pull individual details out of there as required.
For example, my image library uses a single nested keywords field, with branches for People, Places, Events, Rating, Plants and Animals. for me, on the desktop it really is the simplest way to tag, and find things.
I personally think it also works exceptionally well in theater view, but the rest of the family don't agree, so I set about using the existing tools to attempt to extract the data from keywords, in order to set up specific views for them. I can't efficiently get People without global match and substitution. They way I get them at the moment works, by getting MC to check each file for up to 18 individual list items, causes an ugly pause, which means they think the button press hasn't worked, so they press a few more times, then MC finishes working out the people, and fires all the cached button presses, leaving them with no idea where they are, muttering to themselves and telling me it's sh*t and doesn't work right!!
That's just me. I know others have examples where they could use this too, but also accept that those that have gone on record are probably less than five, and MrC has alluded that this may be considerably more than just ticking a box to turn it on, so I appreciate that this is no small request, but it's still something I'd like to play with
Similar to RemoveCharacters(), I've often wished replace() could be used in a similar fashion, so, ReplaceCharacters([Name],//\?*:,_,0) would replace all occurrences of any of those characters with an underscore.
In a detailed category view, MC presents us with group specific information, such as number of tracks in an album, number of tracks by an artist, average ratings etc. etc.
I've often wished we could get at this information from the expression engine, but my head begins to hurt when I try to think how that could be done. I figured if it was feasible, we'd have it already!
Aside from that, I'm blissfully happy with the current status of expressions in MC. The stuff you can do with them, especially with things like listbuild() in theater view, never cease to make me smile. At $50 and 20Mb, MC really is a remarkable achievement.
-marko