Function moveInLine

src/codemirror.js:8706–8711

(line, pos, dir, byUnit)

  }

  function moveInLine(line, pos, dir, byUnit) {
    if (!byUnit) return pos + dir;
    do pos += dir;
    while (pos > 0 && isExtendingChar(line.text.charAt(pos)));
    return pos;
  }

  // This is needed in order to move 'visually' through bi-directional
  // text -- i.e., pressing left should make the cursor go left, even