ucc.c
int expect_number() {
  if (token->kind != TK_NUM)
    error("It is not int");
  int val = token->val;
  token = token->next;
  return (val);
}
// If next toke is int, read next token then return it
// If it is not, return error
If next toke is int, read next token then return it
If it is not, return error
If next toke is int read next token then return it If it is not return error
int expect_number() {
  if (token->kind != TK_NUM)
    error("It is not int");
  int val = token->val;
  token = token->next;
  return (val);
}
int expect_number ( ) { if ( token -> kind != TK_NUM ) error ( " " ) ; int val = token -> val ; token = token -> next ; return ( val ) ; }
If next toke is int, read next token then return it
If it is not, return error
If next toke is int read next token then return it If it is not return error