Function adjustForChange

static/editor.md/lib/codemirror/lib/codemirror.js:4107–4114

(pos, change)

  // Adjust a position to refer to the post-change position of the
  // same text, or the end of the change if the change covers it.
  function adjustForChange(pos, change) {
    if (cmp(pos, change.from) < 0) return pos;
    if (cmp(pos, change.to) <= 0) return changeEnd(change);

    var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
    if (pos.line == change.to.line) ch += changeEnd(change).ch - change.to.ch;
    return Pos(line, ch);
  }

  function computeSelAfterChange(doc, change) {
    var out = [];