Question

I am thinking a library already exists for this, but I need allow my users to create a numbering format for their documents.

For example, let’s say we have an RFI from and the user has a specific format the numbering sequence needs to be in. A typical RFI number looks like this for their system: R0000100. The next RFI in line would be R0000101.

Before I set out to creating a formatting engine for numbers such as these, does something already exist that can accommodate this?

Update:
I failed to save the edit to this question. Anyway, I also want to give the users the ability to create their own formats. So, I may have a form where they can input the format: R####### And also allow them to specify the starting integer: in the case 100. Also, I may want to allow them to specify how they want to increment. maybe only by 100s. So the next number may be R0000200. I know this may sound ridiculous, but you never know. That is why I asked if something like this already exists.

Answer 1

If you keep value and format separated, you won’t need a library or such a thing.

The numbers would be simple, say, integers i, i.e. 100, 101, 102, that you manage/store however you see fit. The formatting part would simply be a matter of R + i.ToString("0000000"), or if you want to have the format as a string literal string.Format("R{0:0000000}", i).

I know, this might only be an example, but as your question stands, the formatting options, that .NET provides out of the box seem to suffice.