I would like to activate ligatures only for some languages. For example, in some European dialects there are specific ligatures valid only for that languages and therefore, I wonder if there was a way to activate them only in some cases.
lookup welsh {
script latn;
language WEL;
sub C H by C_H.loclWEL;
sub D D by D_D.loclWEL;
sub F F by F_F.loclWEL;
sub L L by L_L.loclWEL;
sub N G by N_G.loclWEL;
sub P H by P_H.loclWEL;
sub R H by R_H.loclWEL;
sub T H by T_H.loclWEL;