static Object unstructure(String text) {
  ret unstructure(text, false);
}

static Object unstructure(String text, final boolean allDynamic) {
  ret unstructure(text, allDynamic, null);
}

static int structure_internStringsLongerThan = 50;
static int unstructure_unquoteBufSize = 100;

static int unstructure_tokrefs; // stats

abstract sclass unstructure_Receiver {
  abstract void set(O o);
}

// classFinder: func(name) -> class (optional)
static Object unstructure(String text, boolean allDynamic,
  O classFinder) {
  if (text == null) ret null;
  ret unstructure_tok(javaTokC_noMLS_iterator(text), allDynamic, classFinder);
}

static O unstructure_reader(BufferedReader reader) {
  ret unstructure_tok(javaTokC_noMLS_onReader(reader), false, null);
}

static O unstructure_tok(final Producer<S> tok, final boolean allDynamic, final O _classFinder) {
  final boolean debug = unstructure_debug;
  
  final class X {
    int i = -1;
    final O classFinder = _classFinder != null ? _classFinder : _defaultClassFinder();
    new HashMap<Integer, O> refs;
    new HashMap<Integer, O> tokrefs;
    new HashSet<S> concepts;
    new HashMap<S, Class> classesMap;
    new L<Runnable> stack;
    S curT;
    char[] unquoteBuf = new char[unstructure_unquoteBufSize];
    
    S unquote(S s) {
      ret unquoteUsingCharArray(s, unquoteBuf); 
    }

    // look at current token
    S t() {
      ret curT;
    }
    
    // get current token, move to next
    S tpp() {
      S t = curT;
      consume();
      ret t;
    }
    
    void parse(final unstructure_Receiver out) {
      S t = t();
      
      int refID = 0;
      if (structure_isMarker(t, 0, l(t))) {
        refID = parseInt(t.substring(1));
        consume();
      }
      final int _refID = refID;
      
      // if (debug) print("parse: " + quote(t));
      
      final int tokIndex = i;  
      parse_inner(refID, tokIndex, new unstructure_Receiver {
        void set(O o) {
          if (_refID != 0)
            refs.put(_refID, o);
          if (o != null)
            tokrefs.put(tokIndex, o);
          out.set(o);
        }
      });
    }
    
    void parse_inner(int refID, int tokIndex, final unstructure_Receiver out) {
      S t = t();
      
      // if (debug) print("parse_inner: " + quote(t));
      
      Class c = classesMap.get(t);
      if (c == null) {
        if (t.startsWith("\"")) {
          S s = internIfLongerThan(unquote(tpp()), structure_internStringsLongerThan);
          out.set(s); ret;
        }
        
        if (t.startsWith("'")) {
          out.set(unquoteCharacter(tpp())); ret;
        }
        if (t.equals("bigint")) {
          out.set(parseBigInt()); ret;
        }
        if (t.equals("d")) {
          out.set(parseDouble()); ret;
        }
        if (t.equals("fl")) {
          out.set(parseFloat()); ret;
        }
        if (t.equals("sh")) {
          consume();
          t = tpp();
          if (t.equals("-")) {
            t = tpp();
            out.set((short) (-parseInt(t)); ret;
          }
          out.set((short) parseInt(t)); ret;
        }
        if (t.equals("-")) {
          consume();
          t = tpp();
          out.set(isLongConstant(t) ? (O) (-parseLong(t)) : (O) (-parseInt(t))); ret;
        }
        if (isInteger(t) || isLongConstant(t)) {
          consume();
          //if (debug) print("isLongConstant " + quote(t) + " => " + isLongConstant(t));
          if (isLongConstant(t)) {
            out.set(parseLong(t)); ret;
          }
          long l = parseLong(t);
          bool isInt = l == (int) l;
          ifdef unstructure_debug
            print("l=" + l + ", isInt: " + isInt);
          endifdef
          out.set(isInt ? (O) Integer.valueOf((int) l) : (O) Long.valueOf(l)); ret;
        }
        if (t.equals("false") || t.equals("f")) {
          consume(); out.set(false); ret;
        }
        if (t.equals("true") || t.equals("t")) {
          consume(); out.set(true); ret;
        }
        if (t.equals("-")) {
          consume();
          t = tpp();
          out.set(isLongConstant(t) ? (O) (-parseLong(t)) : (O) (-parseInt(t))); ret;
        }
        if (isInteger(t) || isLongConstant(t)) {
          consume();
          //if (debug) print("isLongConstant " + quote(t) + " => " + isLongConstant(t));
          if (isLongConstant(t)) {
            out.set(parseLong(t)); ret;
          }
          long l = parseLong(t);
          bool isInt = l == (int) l;
          ifdef unstructure_debug
            print("l=" + l + ", isInt: " + isInt);
          endifdef
          out.set(isInt ? (O) Integer.valueOf((int) l) : (O) Long.valueOf(l)); ret;
        }
        
        if (t.equals("File")) {
          consume();
          File f = new File(unquote(tpp()));
          out.set(f); ret;
        }
        
        if (t.startsWith("r") && isInteger(t.substring(1))) {
          consume();
          int ref = Integer.parseInt(t.substring(1));
          O o = refs.get(ref);
          if (o == null)
            fail("unsatisfied back reference " + ref);
          out.set(o); ret;
        }
      
        if (t.startsWith("t") && isInteger(t.substring(1))) {
          consume();
          int ref = Integer.parseInt(t.substring(1));
          O o = tokrefs.get(ref);
          if (o == null)
            fail("unsatisfied token reference " + ref + " at " + tokIndex);
          out.set(o); ret;
        }
        
        if (t.equals("hashset")) ret with parseHashSet(out);
        if (t.equals("lhs")) ret with parseLinkedHashSet(out);
        if (t.equals("treeset")) ret with parseTreeSet(out);
        if (t.equals("ciset")) ret with parseCISet(out);
        
        if (eqOneOf(t, "hashmap", "hm")) {
          consume();
          parseMap(new HashMap, out);
          ret;
        }
        if (t.equals("lhm")) {
          consume();
          parseMap(new LinkedHashMap, out);
          ret;
        }
        if (t.equals("tm")) {
          consume();
          parseMap(new TreeMap, out);
          ret;
        }
        if (t.equals("cimap")) {
          consume();
          parseMap(ciMap(), out);
          ret;
        }
        
        if (t.equals("ll")) {
          consume();
          ret with parseList(new LinkedList, out);
        }

        if (t.equals("syncLL")) {
          consume();
          ret with parseList(synchroLinkedList(), out);
        }

        if (t.equals("sync")) {
          consume();
          if (t().equals("tm")) {
            consume();
            ret with parseMap(synchronizedTreeMap(), out);
          }
          if (t().equals("["))
            ret with parseList(synchroList(), out);
          ret with parseMap(synchronizedMap(), out);
        }
        if (t.equals("{")) {
          parseMap(out); ret;
        }
        if (t.equals("[")) {
          this.parseList(new ArrayList, out); ret;
        }
        if (t.equals("bitset")) {
          parseBitSet(out); ret;
        }
        if (t.equals("array") || t.equals("intarray")) {
          parseArray(out); ret;
        }
        if (t.equals("ba")) {
          consume();
          S hex = unquote(tpp());
          out.set(hexToBytes(hex)); ret;
        }
        if (t.equals("boolarray")) {
          consume();
          int n = parseInt(tpp());
          S hex = unquote(tpp());
          out.set(boolArrayFromBytes(hexToBytes(hex), n)); ret;
        }
        if (t.equals("class")) {
          out.set(parseClass()); ret;
        }
        if (t.equals("l")) {
          parseLisp(out); ret;
        }
        if (t.equals("null")) {
          consume(); out.set(null); ret;
        }
        
        if (eq(t, "c")) {
          consume("c");
          t = t();
          assertTrue(isJavaIdentifier(t));
          concepts.add(t);
        }
      }
      
      if (eq(t, "j")) {
        consume("j");
        out.set(parseJava()); ret;
      }

      if (c == null && !isJavaIdentifier(t))
        throw new RuntimeException("Unknown token " + (i+1) + ": " + t);
        
      // any other class name (or package name)
      consume();
      S className, fullClassName;
      
      // Is it a package name?
      if (eq(t(), ".")) {
        consume();
        className = fullClassName = t + "." + assertIdentifier(tpp());
      } else {
        className = t;
        fullClassName = "main$" + t;
      }
      
      if (c == null) {
        // First, find class
        if (allDynamic) c = null;
        else c = classFinder != null ? (Class) callF(classFinder, fullClassName) : findClass_fullName(fullClassName);
        if (c != null)
          classesMap.put(className, c);
      }
          
      // Check if it has an outer reference
      bool hasBracket = eq(t(), "(");
      if (hasBracket) consume();
      bool hasOuter = hasBracket && eq(t(), "this$1");
      
      DynamicObject dO = null;
      O o = null;
      fS thingName = t;
      if (c != null) {
        o = hasOuter ? nuStubInnerObject(c, classFinder) : nuEmptyObject(c);
        if (o instanceof DynamicObject) dO = (DynamicObject) o;
      } else {
        if (concepts.contains(t) && (c = findClass("Concept")) != null)
          o = dO = (DynamicObject) nuEmptyObject(c);
        else
          dO = new DynamicObject;
        dO.className = className;
        ifdef unstructure_debug
          print("Made dynamic object " + t + " " + shortClassName(dO));
        endifdef
      }
      
      // Save in references list early because contents of object
      // might link back to main object
      
      if (refID != 0)
        refs.put(refID, o != null ? o : dO);
      tokrefs.put(tokIndex, o != null ? o : dO);
      
      // NOW parse the fields!
      
      final new LinkedHashMap<S, O> fields; // preserve order
      final O _o = o;
      final DynamicObject _dO = dO;
      if (hasBracket) {
        stack.add(r {
          if (eq(t(), ")")) {
            consume(")");
            objRead(_o, _dO, fields);
            out.set(_o != null ? _o : _dO);
          } else {
            final S key = unquote(tpp());
            if (!eq(tpp(), "="))
              fail("= expected, got " + t() + " after " + quote(key) + " in object " + thingName /*+ " " + sfu(fields)*/);
            stack.add(this);
            parse(new unstructure_Receiver {
              void set(O value) {
                fields.put(key, value);
                if (eq(t(), ",")) consume();
              }
            });
          }
        });
      } else {
        objRead(o, dO, fields);
        out.set(o != null ? o : dO);
      }
    }
    
    void objRead(O o, DynamicObject dO, Map<S, O> fields) {
      ifdef unstructure_debug
      print("objRead " + className(o) + " " + className(dO) + " " + struct(fields));
      endifdef
      if (o != null)
        if (dO != null) {
          ifdef unstructure_debug
            printStructure("setOptAllDyn", fields);
          endifdef
          setOptAllDyn(dO, fields);
        } else {
          setOptAll_pcall(o, fields);
          ifdef unstructure_debug
            print("objRead now: " + struct(o));
          endifdef
        }
      else for (Map.Entry<S, O> e : fields.entrySet())
        setDynObjectValue(dO, intern(e.getKey()), e.getValue());

      if (o != null)
        pcallOpt_noArgs(o, "_doneLoading");
    }
    
    void parseSet(final Set set, final unstructure_Receiver out) {
      this.parseList(new ArrayList, new unstructure_Receiver {
        void set(O o) {
          set.addAll((L) o);
          out.set(set);
        }
      });
    }
    
    void parseLisp(final unstructure_Receiver out) {
      ifclass Lisp
        consume("l");
        consume("(");
        final new ArrayList list;
        stack.add(r {
          if (eq(t(), ")")) {
            consume(")");
            out.set(Lisp((S) list.get(0), subList(list, 1)));
          } else {
            stack.add(this);
            parse(new unstructure_Receiver {
              void set(O o) {
                list.add(o);
                if (eq(t(), ",")) consume();
              }
            });
          }
        });
        if (false) // skip fail line
      endif
      
      fail("class Lisp not included");
    }
    
    void parseBitSet(final unstructure_Receiver out) {
      consume("bitset");
      consume("{");
      final new BitSet bs;
      stack.add(r {
        if (eq(t(), "}")) {
          consume("}");
          out.set(bs);
        } else {
          stack.add(this);
          parse(new unstructure_Receiver {
            void set(O o) {
              bs.set((Integer) o);
              if (eq(t(), ",")) consume();
            }
          });
        }
      });
    }
    
    void parseList(final L list, final unstructure_Receiver out) {
      consume("[");
      stack.add(r {
        if (eq(t(), "]")) {
          consume("]");
          out.set(list);
        } else {
          stack.add(this);
          parse(new unstructure_Receiver {
            void set(O o) {
              //if (debug) print("List element type: " + getClassName(o));
              list.add(o);
              if (eq(t(), ",")) consume();
            }
          });
        }
      });
    }
    
    void parseArray(final unstructure_Receiver out) {
      final S type = tpp();
      consume("{");
      final List list = new ArrayList;
      
      stack.add(r {
        if (eq(t(), "}")) {
          consume("}");
          out.set(type.equals("intarray") ? toIntArray(list) : list.toArray());
        } else {
          stack.add(this);
          parse(new unstructure_Receiver {
            void set(O o) {
              list.add(o);
              if (eq(t(), ",")) consume();
            }
          });
        }
      });
    }
    
    Object parseClass() {
      consume("class");
      consume("(");
      S name = unquote(tpp());
      consume(")");
      Class c = allDynamic ? null : classFinder != null ? (Class) callF(classFinder, name) : findClass_fullName(name);
      if (c != null) ret c;
      new DynamicObject dO;
      dO.className = "java.lang.Class";
      name = dropPrefix("main$", name);
      dO.fieldValues.put("name", name);
      ret dO;
    }
    
    Object parseBigInt() {
      consume("bigint");
      consume("(");
      S val = tpp();
      if (eq(val, "-"))
        val = "-" + tpp();
      consume(")");
      ret new BigInteger(val);
    }
    
    Object parseDouble() {
      consume("d");
      consume("(");
      S val = unquote(tpp());
      consume(")");
      ret Double.parseDouble(val);
    }
    
    Object parseFloat() {
      consume("fl");
      S val;
      if (eq(t(), "(")) {
        consume("(");
        val = unquote(tpp());
        consume(")");
      } else {
        val = unquote(tpp());
      }
      ret Float.parseFloat(val);
    }
    
    void parseHashSet(unstructure_Receiver out) {
      consume("hashset");
      parseSet(new HashSet, out);
    }
    
    void parseLinkedHashSet(unstructure_Receiver out) {
      consume("lhs");
      parseSet(new LinkedHashSet, out);
    }
    
    void parseTreeSet(unstructure_Receiver out) {
      consume("treeset");
      parseSet(new TreeSet, out);
    }
    
    void parseCISet(unstructure_Receiver out) {
      consume("ciset");
      parseSet(ciSet(), out);
    }
    
    void parseMap(unstructure_Receiver out) {
      parseMap(new TreeMap, out);
    }
    
    O parseJava() {
      S j = unquote(tpp());
      new Matches m;
      if (jmatch("java.awt.Color[r=*,g=*,b=*]", j, m))
        ret nuObject("java.awt.Color", parseInt($1), parseInt($2), parseInt($3));
      else {
        warn("Unknown Java object: " + j);
        null;
      }
    }
    
    void parseMap(final Map map, final unstructure_Receiver out) {
      consume("{");
      stack.add(new Runnable {
        bool v;
        O key;
        
        public void run() { 
          if (v) {
            v = false;
            stack.add(this);
            if (!eq(tpp(), "="))
              fail("= expected, got " + t() + " in map of size " + l(map));

            parse(new unstructure_Receiver {
              void set(O value) {
                map.put(key, value);
                ifdef unstructure_debug
                  print("parseMap: Got value " + getClassName(value) + ", next token: " + quote(t()));
                endifdef
                if (eq(t(), ",")) consume();
              }
            });
          } else {
            if (eq(t(), "}")) {
              consume("}");
              out.set(map);
            } else {
              v = true;
              stack.add(this);
              parse(new unstructure_Receiver {
                void set(O o) {
                  key = o;
                }
              });
            }
          } // if v else
        } // run()
      });
    }
    
    /*void parseSub(unstructure_Receiver out) {
      int n = l(stack);
      parse(out);
      while (l(stack) > n)
        stack
    }*/
    
    void consume() { curT = tok.next(); ++i; }
    
    void consume(S s) {
      if (!eq(t(), s)) {
        /*S prevToken = i-1 >= 0 ? tok.get(i-1) : "";
        S nextTokens = join(tok.subList(i, Math.min(i+2, tok.size())));
        fail(quote(s) + " expected: " + prevToken + " " + nextTokens + " (" + i + "/" + tok.size() + ")");*/
        fail(quote(s) + " expected, got " + quote(t()));
      }
      consume();
    }
    
    void parse_x(unstructure_Receiver out) {
      consume(); // get first token
      parse(out);
      while (nempty(stack))
        popLast(stack).run();
    }
  }
  
  Bool b = DynamicObject_loading!;
  DynamicObject_loading.set(true);
  try {
    final new Var v;
    new X x;
    x.parse_x(new unstructure_Receiver {
      void set(O o) { v.set(o); }
    });
    unstructure_tokrefs = x.tokrefs.size();
    ret v.get();
  } finally {
    DynamicObject_loading.set(b);
  }
}

static boolean unstructure_debug;

Began life as a copy of #1005980