codemirror/CodeMirror — pull request #2837 by i-tu (2014-10-05 15:22:17+00:00)
Title: Enable Ligatures

This change enables ligature support for special programming fonts featuring them. (See https://github.com/i-tu/Hasklig)

I don't know how this ultimately effects performance, but I haven't had any problems using this css change with Light Table.