Reworking the tpp file format

A few weeks ago, Sven reminded me of an inherent problem of the current design of tpp's file format, namely it's line-based file format which gives no options to e.g. set text properties like bold or underlined for only a single word or a phrase. Currently, the whole line must be made bold, underlined or whatever.

For those who don't know: tpp is the "PowerPoint for the console" that I wrote together with Nico Golde and currently the (IMHO) only mature solution to do presentations solely using text terminals.

A quick look over the existing commands in the current file format shows three (no, four, nobody
expects the Spanish Inquisition!) classes of commands:

• presentation-wide commands: presentation title, author, date, header, footer, border
• slide-wide commands: header, footer (to override to presentation-wide default, if set)
• line-wide commands: output, shell output, special effects, alignment
• character-wide commands: text color, text properties like bold, underlined, reverse, ...

Now, the goal is to reflect this new specialization and change in what tpp should provide into a new, better file format, to make tpp more flexible than right now.

One option would be to use an XML schema, but that is not a very attractive option, since XML would be a lot too verbose to actually make it fun to write tpp presentations.

Another approach would be to keep with most of the current problems, and to introduce additional, Wiki-like formatting methods, like using stars or underlines or something like [bold|The text supposed to be bold] or [bold,fgcolor=blue,bgcolor=white|blue/white text, bold]. The only disadvantage: it would make the parser a lot more difficult than it currently is. But probably it is
too simple, anyway.

So, what's your opinion on that? I would like to hear your comments, and to do some brainstorming instead of just starting some experimental quick-shot implementation.