I spend yesterday writing my first “generators” as scripts are called in MetaEdit+ and I must say I have mixed feelings. I was able to do most of what I set out to do, but often I had to bend over backwards to make things happen and that’s in no small part to the stack concept that the scripting language uses. Basically what you do is you start from some point in your diagram, then iterate over all things of a given type and then from there repel to the next thing like a monkey in the jungle and this way you build up a stack that you have to climb back up again. So sidestepping into other objects or iterating over unrelated objects to search any of them that somehow relate to the one on the stack that you are operating on, is difficult.
It’s also missing array features and you can not actually program a loop with an index variable only iterate over all items of a given type from the item that’s at the top of the work stack, so it is not easy.
On the plus side, I was able to write two complete generators in one day as a complete newbie and given the lack of powerful features that speaks to the ease with which the language can be learned, probably because there aren’t that many features. The tutorials are a bit confusing because they refer to a sample graph that I did not really work through (a language to describe displays for digital watches) but when I read the reference manual one by one, it became clear.
So all in all I would say, there is no real alternative to MetaEdit+ currently. Doing the same stuff with yEdit or Visio would be a pain in the ass, so it is certainly a useful tool. However the price is quite high. I was lucky to get an introductory packet which is about 200$ for a 1 year license and you have to renew it every year for the same price. Although I am not one to buy licenses this way usually, in this case I had no choice because there is no competition. However the professional licenses out there start at 4000$ for a package that comes with a 2 day personal training session on site (not sure if on theirs or on yours) and then 300$ per month per workstation. So it is certainly nothing you want to buy for your small software corporation. When you look at the list of customers on their website, it’s mostly academic institutions and big corporations, so I guess they can afford this.
I could really see a market for that sort of software if it were cheaper, but as prices are now, I think most people will stick with simple diagram editors and take their deficiencies over paying these prices.