mode-transform.js

    this.transformInput = function(state, editor, session, text) {
        if (text == '`') {
            var selection = editor.getSelectionRange();
            var selected = session.doc.getTextRange(selection);
            if (selected !== "") {
                return {
                    text: '`' + selected + '`',
                    selection: false
                }
            } else {
                return {
                    text: '``',
                    selection: [1,1]
                }
            }
        }
        return false;
    }
    
    this.transformRemove = function(state, editor, session, range) {
        var selected = session.doc.getTextRange(range);
        if (!range.isMultiLine() && selected == '`') {
            var rightChar = session.doc.getLine(range.start.row).substring(range.start.column+1, range.start.column+2);
            if (rightChar == '`') {
                return new Range(range.start.row, range.start.column, range.start.row, range.end.column+1);
            }
        }
        return range;
    }