Function visualLine

static/editor.md/lib/codemirror/lib/codemirror.js:6364–6369

(line)

  // visual line. This finds the start of the visual line that the
  // given line is part of (usually that is the line itself).
  function visualLine(line) {
    var merged;
    while (merged = collapsedSpanAtStart(line))
      line = merged.find(-1, true).line;
    return line;
  }

  // Returns an array of logical lines that continue the visual line
  // started by the argument, or undefined if there are no such lines.