!747
!multi-line strings

m {
  !include #1001509 // rules & statements
  
  static Map<S, L<S>> synMap = new TreeMap<S, L<S>>();
  
  p {
    statements.add("one is a synonym of 1.");
    statements.add("\"eins\" is a synonym of 1.");
    statements.add("two is a synonym of 2.");
    
    makeSynMap();
    
    ask([[what are the synonyms of 1?]]);
    ask([[what are the synonyms of 2?]]);
  }
  
  static void makeSynMap() {
    for (Map<S, S> m : matchStatements("$1 is a synonym of $2"))
      addSynonym(unquote(m.get("$1")), unquote(m.get("$2")));
  }
  
  static void addSynonym(S a, S b) {
    L<S> la = synMap.get(a), lb = synMap.get(b);
    if (la == null && lb == null) {
      L<S> l = litlist(a, b);
      synMap.put(a, l);
      synMap.put(b, l);
    } else if (la == lb) {
      // nothing to do, they're already synonyms
    } else if (lb == null) {
      la.add(b);
      synMap.put(b, la);
    } else if (la == null) {
      lb.add(a);
      synMap.put(a, lb);
    } else
      mergeLists(la, lb);
  }
  
  static void mergeLists(L<S> la, L<S> lb) {
    for (S b : lb) {
      la.add(b);
      synMap.put(b, la);
    }
  }
  
  static void ask(S q) {
    print("? " + q);
    
    new Map<S, S> map;
    if (match4("what are the synonyms of $1?", q, map))
      print("  => " + structure(getSynonyms(map.get("$1"))));
    else
      print("dunno.");
  }
  
  static L<S> getSynonyms(S x) {
    ret synMap.get(x);
  }
}

Began life as a copy of #1001510