This FLS5 module can be used to export FontLab class-kerning to adjacent UFO files. It works for both single- and Multiple Master VFBs.

The module needs to be called with a fl.font object, and a prefixOption. The prefixOption is used for renaming kerning classes to work in various UFO-related scenarios.

If the prefixOption is None, class names will be prefixed with @L_ and @R_`, to keep track of their side (in case they need to be converted the opposite way and re-imported to FL).

The prefix options are:

• MM: convert class names to MetricsMachine-readable group names
• UFO3: convert to UFO3-style class names

usage (one of the three):

flKernExport.ClassKerningToUFO(fl.font)
flKernExport.ClassKerningToUFO(fl.font, prefixOption='MM')
flKernExport.ClassKerningToUFO(fl.font, prefixOption='UFO3')