#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lex.yy.c"

typedef struct _node {
   char *name;
   struct _node *next;
} node;
typedef node *symboltable;

symboltable addtbl ( symboltable T, char *id )
{
   node *p;

   p = T;
   while (p) {
      if (!strcmp(p->name,id)) {
         printf("Identifier %s already exists\n", id);
         return T;
      }
      p = p -> next;
   }
   printf("Adding new identifier: %s\n", id);
   p = (node *)malloc(sizeof(node));
   p -> name = (char *)malloc((strlen(id)+1) * sizeof(char));
   strcpy(p -> name, id);
   p -> next = T;
   return p;
}

int main ()
{
   int nextok;
   symboltable T = NULL;

   while ((nextok = yylex())) {
      switch (nextok) {
         case LP: printf("Beginning of subexpression\n"); break;
         case RP: printf("End of subexpression\n"); break;
         case NUM: printf("Number: %s\n", yytext); break;
         case OP: printf("Operator: %s\n", yytext); break;
         case ID: T = addtbl(T,yytext); break;
         case ASG: printf("Assignment\n"); break;
         default: printf("Unknown token\n"); break;
      }
   }

   exit(0);
}