String parsing - better solution needed :-(

Question

Hi Folks,
Basically I will be taking in a string that represents the name of the output file the user wants, this will be specified in an xml file. The issue I have is that it needs to have non-static elements as part of the name as well (like a timestamp). This can come from two places: 1) the applications map 2)Predefined list of functions. Anything that will be comng from the map will have square brackets around it [], whilst anything the refers to a function will be inside curly brackets {}.
So I may get a string in the form: filename_[user.id]_{datestamp}.pdf
This should be output in a file called: filename_12345_2811208.pdf
My issue is with evaluating the string, to determine what needs to be left as is, replaced with a value from a function, or replaced with a value from the map. I have looked at tokenizing the string and using indexof, but these are more trouble than they are worth. My current solution is, to have 4 booleans- one representing an open and close bracket of each type. When two matching booleans are true (i.e. detected an open and closed square bracket) take the sub-string between the brackets (to do this I use two ints representing the index of the brackets), evaluate it and append it to the output string.
I have tested this and it works- but I was wondering if there is some other method that works better, as quite frankly my solution is the sort of embarassing crud you would see from a first year student programmer. Any help at all would be massively appreciated.
Cheers,
Max

Answer 1

Hi swmtgoet_x,
Thanks for the speedy reply- and your understanding of the problem is spot on.
I had looked at the replace method- the only issue with that is that I have no way of knowing which value the users will want from the map (depending on how they have it implemented there could be hundreds of things in there), so to search the string for any value in the map would be hugely ineffecient :-(
But having said that- I could look at using that approach for "pre-defined function"- I don't think there will be many of these, but in typical fashion no one has seen fit to gove me a list yet.....so I get to guess. :-s