예제 #1
0
파일: reference.c 프로젝트: Preetam/ponyc
bool expr_this(pass_opt_t* opt, ast_t* ast)
{
  typecheck_t* t = &opt->check;

  if(t->frame->def_arg != NULL)
  {
    ast_error(ast, "can't reference 'this' in a default argument");
    return false;
  }

  sym_status_t status;
  ast_get(ast, stringtab("this"), &status);

  if(status == SYM_CONSUMED)
  {
    ast_error(ast, "can't use a consumed 'this' in an expression");
    return false;
  }

  assert(status == SYM_NONE);
  token_id cap = cap_for_this(t);

  if(!cap_sendable(cap) && (t->frame->recover != NULL))
    cap = TK_TAG;

  bool make_arrow = false;

  if(cap == TK_BOX)
  {
    cap = TK_REF;
    make_arrow = true;
  }

  ast_t* type = type_for_this(opt, ast, cap, TK_NONE, false);

  if(make_arrow)
  {
    BUILD(arrow, ast, NODE(TK_ARROW, NODE(TK_THISTYPE) TREE(type)));
    type = arrow;
  }

  // Get the nominal type, which may be the right side of an arrow type.
  ast_t* nominal;
  bool arrow;

  if(ast_id(type) == TK_NOMINAL)
  {
    nominal = type;
    arrow = false;
  } else {
    nominal = ast_childidx(type, 1);
    arrow = true;
  }

  ast_t* typeargs = ast_childidx(nominal, 2);
  ast_t* typearg = ast_child(typeargs);

  while(typearg != NULL)
  {
    if(!expr_nominal(opt, &typearg))
    {
      ast_error(ast, "couldn't create a type for 'this'");
      ast_free(type);
      return false;
    }

    typearg = ast_sibling(typearg);
  }

  if(!expr_nominal(opt, &nominal))
  {
    ast_error(ast, "couldn't create a type for 'this'");
    ast_free(type);
    return false;
  }

  if(arrow)
    type = ast_parent(nominal);
  else
    type = nominal;

  ast_settype(ast, type);
  return true;
}
예제 #2
0
파일: reference.c 프로젝트: tmmcguire/ponyc
bool expr_this(pass_opt_t* opt, ast_t* ast)
{
  typecheck_t* t = &opt->check;

  if(t->frame->def_arg != NULL)
  {
    ast_error(opt->check.errors, ast,
      "can't reference 'this' in a default argument");
    return false;
  }

  sym_status_t status;
  ast_get(ast, stringtab("this"), &status);

  if(status == SYM_CONSUMED)
  {
    ast_error(opt->check.errors, ast,
      "can't use a consumed 'this' in an expression");
    return false;
  }

  assert(status == SYM_NONE);
  token_id cap = cap_for_this(t);

  if(!cap_sendable(cap) && (t->frame->recover != NULL))
  {
    ast_t* parent = ast_parent(ast);
    if(ast_id(parent) != TK_DOT)
      cap = TK_TAG;
  }

  bool make_arrow = false;

  if(cap == TK_BOX)
  {
    cap = TK_REF;
    make_arrow = true;
  }

  ast_t* type = type_for_this(opt, ast, cap, TK_NONE, false);

  if(make_arrow)
  {
    BUILD(arrow, ast, NODE(TK_ARROW, NODE(TK_THISTYPE) TREE(type)));
    type = arrow;
  }

  // Get the nominal type, which may be the right side of an arrow type.
  ast_t* nominal;
  bool arrow;

  if(ast_id(type) == TK_NOMINAL)
  {
    nominal = type;
    arrow = false;
  } else {
    nominal = ast_childidx(type, 1);
    arrow = true;
  }

  ast_t* typeargs = ast_childidx(nominal, 2);
  ast_t* typearg = ast_child(typeargs);

  while(typearg != NULL)
  {
    if(!expr_nominal(opt, &typearg))
    {
      ast_error(opt->check.errors, ast, "couldn't create a type for 'this'");
      ast_free(type);
      return false;
    }

    typearg = ast_sibling(typearg);
  }

  if(!expr_nominal(opt, &nominal))
  {
    ast_error(opt->check.errors, ast, "couldn't create a type for 'this'");
    ast_free(type);
    return false;
  }

  // Unless this is a field lookup, treat an incomplete `this` as a tag.
  ast_t* parent = ast_parent(ast);
  bool incomplete_ok = false;

  if((ast_id(parent) == TK_DOT) && (ast_child(parent) == ast))
  {
    ast_t* right = ast_sibling(ast);
    assert(ast_id(right) == TK_ID);
    ast_t* find = lookup_try(opt, ast, nominal, ast_name(right));

    if(find != NULL)
    {
      switch(ast_id(find))
      {
        case TK_FVAR:
        case TK_FLET:
        case TK_EMBED:
          incomplete_ok = true;
          break;

        default: {}
      }
    }
  }

  if(!incomplete_ok && is_this_incomplete(t, ast))
  {
    ast_t* tag_type = set_cap_and_ephemeral(nominal, TK_TAG, TK_NONE);
    ast_replace(&nominal, tag_type);
  }

  if(arrow)
    type = ast_parent(nominal);
  else
    type = nominal;

  ast_settype(ast, type);
  return true;
}