Function findPosH

src/codemirror.js:4839–4886

(doc, pos, dir, unit, visually)

  // position. The resulting position will have a hitSide=true
  // property if it reached the end of the document.
  function findPosH(doc, pos, dir, unit, visually) {
    var line = pos.line, ch = pos.ch, origDir = dir;
    var lineObj = getLine(doc, line);
    function findNextLine() {
      var l = line + dir;
      if (l < doc.first || l >= doc.first + doc.size) return false
      line = l;
      return lineObj = getLine(doc, l);
    }
    function moveOnce(boundToLine) {
      var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
      if (next == null) {
        if (!boundToLine && findNextLine()) {
          if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
          else ch = dir < 0 ? lineObj.text.length : 0;
        } else return false
      } else ch = next;
      return true;
    }

    if (unit == "char") {
      moveOnce()
    } else if (unit == "column") {
      moveOnce(true)
    } else if (unit == "word" || unit == "group") {
      var sawType = null, group = unit == "group";
      var helper = doc.cm && doc.cm.getHelper(pos, "wordChars");
      for (var first = true;; first = false) {
        if (dir < 0 && !moveOnce(!first)) break;
        var cur = lineObj.text.charAt(ch) || "\n";
        var type = isWordChar(cur, helper) ? "w"
          : group && cur == "\n" ? "n"
          : !group || /\s/.test(cur) ? null
          : "p";
        if (group && !first && !type) type = "s";
        if (sawType && sawType != type) {
          if (dir < 0) {dir = 1; moveOnce();}
          break;
        }

        if (type) sawType = type;
        if (dir > 0 && !moveOnce(!first)) break;
      }
    }
    var result = skipAtomic(doc, Pos(line, ch), pos, origDir, true);
    if (!cmp(pos, result)) result.hitSide = true;
    return result;
  }

  // For relative vertical movement. Dir may be -1 or 1. Unit can be
  // "page" or "line". The resulting position will have a hitSide=true