Function clipLine

static/editor.md/lib/codemirror/lib/codemirror.js:1991–1991

(doc, n)

  // Most of the external API clips given positions to make sure they
  // actually exist within the document.
  function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
  function clipPos(doc, pos) {
    if (pos.line < doc.first) return Pos(doc.first, 0);
    var last = doc.first + doc.size - 1;