!7

static LPair<IntRange> arrows = synchroList();

p-experiment {
  S text = lines(sentencesAfterLines_withPeriodOnly(mechList_raw("Simple Wikipedia: Peafowl")));
  //jtextpane(text)
  JTextPane tp = swing(func -> JTextPane {
    ret new JTextPane {
      public void paint(Graphics _g) {
        Graphics2D g = cast _g;
        super.paint(g);
        
        pcall {
          Color arrowColor = colorWithAlpha(Color.red, 0.3);
          S text = getText();
          for (Pair<IntRange> p : cloneList(arrows)) {
            Rect r1 = textComponent_substringRect(this, p.a);
            Rect r2 = textComponent_substringRect(this, p.b);
            if (r1 != null && r2 != null) {
              fillRect(g, r1, colorWithAlpha(Color.green, 0.2));
              fillRect(g, r2, colorWithAlpha(Color.red, 0.2));
              //drawArrowBetweenRects(g, r1, r2, arrowColor);
              drawArrowBetweenPoints(g, centerOfRect(r1), centerOfRect(r2), arrowColor);
            } else if (r1 != null)
              drawText(g, "?", centerTextInRect(g.getFontMetrics(), "?", r1), arrowColor);
          }
        }
      }
    };
  });
  setTextCaret0(tp, text);
  
  L<S> tok = javaTok(text);
  addPair(arrows,
    tokenToCharRange(tok, indexOfIC(tok, "it")),
    tokenToCharRange(tok, indexOfIC(tok, "peafowl")));

  Set<S> set = mechSetCI("Backreferencing words");
  Set<IntRange> have = asHashSet(firstOfPairs(arrows));
  for (int i = 1; i < l(tok); i += 2)
    if (set.contains(tok.get(i)) && !arrows.contains(tokenToCharRange(tok, i)))
      addPair(arrows, tokenToCharRange(tok, i), null); // show question mark
      
  showFrame(setFontSize(30, tp));
  
  hideConsole();
}