Best Practices in Building and Processing Macros

I'm building an IOS application, and would like to offer the user the ability to use macros for different aspects of the system.

For example, I might have a simple macro this this:

{include name="some name" pre="some it of htmk" post="some other bit of html"}

That would include the contents of the item named "some name" in the body of the document the user is working on.

or I might have something more complex like this:

{notesForTag name={ListAllTags pre="some bit of html" post="some other bit of html"} pre="..." post="..."}

Which would list all the documents in the system grouped by tag.. the ability to add on data (like html) at the beginning and the end of each tag returned would allow the user, for example, to format the response as a table, or use particular styling, etc.

Conceptually, I know how I want this to work, but I'm wondering if there are any macro construction and processing best practices out there that would help me on my way. Anything geared towards Objective C / IOS would be most helpful.

Edit: To add some clarity here, what I'm looking to discover is an efficient and accurate way to parse something like thi开发者_JS百科s. Having parsed things, I think the rest will be fairly straightforward.

Thank you.

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NSScanner would probably work well for parsing something like this, perhaps with a recursive function to allow nested macros like the second one. You may also want to consider using XML to represent your macros, which would allow you to use NSXMLParser to parse it, so you only have to worry about the content and not the structure.