In article , Andre Caldas wrote:

Hello, list!

I am writing down a macro package for commutative diagrams using metafun. This is my first try: https://bitbucket.org/andrecaldas/math-video-classes/src/9a050eab20348c9a9c9... 0740618173648979f45/src/environments/diagrams.tex?at=default

Used here: https://bitbucket.org/andrecaldas/math-video-classes/src/9a050eab2034/src/pr... ucts/assorted/open_mapping_theorem/notes/introduction.tex?at=default#cl-106

But I would like to use some "object oriented" like approach. That is, I'd like the diagram data structure to be set up like this:

d = CD.new; d.vertex("$X$"); d.arrow("$f$"); d.vertex("$Y$"); d.newline; d.arrow("$\pi$"); d.arrow("$\pi$"); d.vertex("$A$"); d.arrow("$g$"); d.vertex("$B$");

or even in some "thelabel" similar fashion,

d = CD.new; CD.vertex(d, "$X$"); CD.arrow(d, "$f$"); CD.vertex(d, "$Y$"); CD.newline(d); CD.arrow(d, "$\pi$"); CD.arrow(d, "$\pi$"); CD.vertex(d, "$A$"); CD.arrow(d, "$g$"); CD.vertex(d, "$B$");

How do I do that in METAFUN/METAPOST?

You may want to take a look at my attempt: http://users.dimi.uniud.it/~nicola.vitacolonna/home/content/metappeal It is a library intended to provide a minimal framework for “oo-like” constructs. It is a work in progress (actually, I have not worked on it for a while since I didn't receive any feedback) and the documentation is a bit messy, but the core is stable and well tested and should be compatible with MetaFun. It is all based on a pair of macros that generalize MetaPost declarations, a first draft of which is shortly described here: http://oldwww.gust.org.pl/projects/pearls/2011p/index_html For the functionality you are describing, you may just need to grab the file metappeal.mp (and the files that it includes) and include it in your source. Nicola