More specifically
How to enable code Discretionary Ligatures "dlig" feature of Recursive font ?
Usual fontLigatures settings.json configuration doesn't work.
"editor.fontFamily": "Recursive Sans Linear"
"editor.fontLigatures": true // Do not work :-/
To enable code ligatures edit VSCode settings.json with desired OpenType features :
// Code ligatures ON
"editor.fontLigatures": "'dlig'"
// BONUS: other feature set (see below)
"editor.fontLigatures": "'ss01', 'ss02', 'ss03', 'ss04', 'ss05', 'ss06', 'zero', 'onum'"
Sources :
Stephen Nixon's article on recursive.design
See also : Microsoft OpenType spec