How could Stringy be improved? I created a programming language for manipulating strings called Stringy. It's very different from other programming languages, since you only have one string (for manipulation) and some variables. With the various commands you can manipulate that one string. I created it because it might be useful for some challenges here. (challenged tagged string)

What could I add to this to make it better/more useful for challenges here?

Examples for the language can be found at GitHub at examples.txt. It might be a bit hard to understand though.
OK, I said I'd put my comments into a more comprehensible form so here they are.


Don't separate commands. Having to use ; every time you want to use a different command is costly. My recommendation on the interpreter side is to parse one character at a time and read more if the command necessitates it.
Add regex (to be honest, I don't know much regex -- it's somewhere on my list of things to learn -- but it seems logical to add it)
On the topic of not separating commands with ;, allow for whitespace to be removeable.
Add loops of some sort.
Add conditionals and conditional tests (equals, not, and, or, etc.)
Add a newline reserved character (n, perhaps?)
Add reserved characters for variables
You have uppercase and lowercase commands, why not add a capitalization one (one that capitalizes the string as if it were a sentence and maybe also capitalizes proper nouns that it can identify).
Add a command to count how many instances of a string are in another.
Add a length command to get the length of a string.
Add a terminate/break command.
Add an equivalent of Python's ord and chr functions.
Add a split at numerical value command (splits at a certain length), and add an alternative to that which splits at every multiple of the numerical value (e.g. for a string of length 10 at 3,6,9 if given the argument 3).
Add a duplication command (akin to Python's "String"*x)


You'll notice that some of these involve numbers -- I think that even for String challenges having a way of working with numbers is good. Perhaps have a stack for storing numbers that is accessed when certain commands are used (e.g. the length command pushes the length onto the number stack and then the split at numerical value uses this length to split the stack).

I'll add more ideas as I think of them, but I feel like my suggestions are pushing this in the direction of a more general-purpose golf language. Hopefully this input helps regardless of whether you use it or not.