calt opentype features-file script

Understanding the OpenType Engine Layout Algorithm

Forums: 

I'm still trying to wrap my head around the OpenType Layout Algorithm. Here's what I have currently, largely adapted from Pecita and OTFPOC:

lookup calt_pass_1 {

sub @can_2s' lookup plain_to_2s
@can_s2' lookup plain_to_s2;

sub @can_s2' lookup plain_to_s2 # matched in [roe][it]
@can_2s' lookup plain_to_2s;

sub @can_2b' lookup plain_to_2b
@can_b2' lookup plain_to_b2;

sub @can_b2' lookup plain_to_b2
@can_2b' lookup plain_to_2b;

} calt_pass_1;