#include <string>
#include "token.h"
#include "node.h"
#include "hashtable.h"
#include "lexan.h"

node * parse_highest(lexan & L)
{ token t = L.next();
  token_type tt = t.gettype();  
  if (tt == tnumber)
    return node::num(t.getvalue());
  else if (tt == tvariable)
    return node::var(t.getstring());
  return node::err("parse_highest"); }

node * parse_power(lexan & Lex)
{ node * L = parse_highest(Lex);
  token t = Lex.next();
  while (true)
  { if (t.gettype() == toperator && t.getstring() == "^")
    { }
    else
      break;
    node * R = parse_highest(Lex);
    node * N = node::op("^");
    N->add(L);
    N->add(R);
    L = N;
    t = Lex.next(); }
  Lex.unnext(t);
  return L; }

node * parse_muldiv(lexan & Lex)
{ node * L = parse_power(Lex);
  token t = Lex.next();
  while (true)
  { if (t.gettype() == toperator && (t.getstring() == "*" ||
                                     t.getstring() == "/"))
    { }
    else
      break;
    node * R = parse_power(Lex);
    node * N = node::op(t.getstring());
    N->add(L);
    N->add(R);
    L = N;
    t = Lex.next(); }
  Lex.unnext(t);
  return L; }

void main()
{ hashtable ht;
  ht.set("x", 123);
  ht.set("cat", 1);
  lexan L;
  node * t = parse_muldiv(L);
  t->print1();
  t->print();
  cout << "\nvalue = " << t->evaluate(ht) << "\n"; }