Pain tells me I can’t do enough typing to support conventionally some of the font handling I’d like, such as subsetting. I’m going to have to use shortcuts by means of fontforge. Fortunately font subsetting should be easy using fontforge’s Python extension and pycaml or calling a script; it’ll just be ugly, and slightly slow, because I’ll have to actually write subsetted fonts to files and then load them again in the OCaml code. (The ‘generate’ function in the fontforge modules writes the generated font to a file, and I can’t think of a strong enough argument to justify giving fontforge the means to write the font into, let’s say, a big string.)
OTOH it’s just this sort of thing I have hoped to be able to do thanks to linking Kompostilo with Python. It isn’t an accident that I have wanted to have Python as a scripting language for the typesetter—unlike all the other general purpose scripting languages, Python has fontforge modules.
(It’s interesting that LuaTeX also has fontforge ‘modules’, and yet has Lua as its only scripting language. What LuaTeX actually has is parts of fontforge’s source code adapted to another purpose and compiled in as part of the typesetting program.)