#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "tree.h"
#include "c-calc.tab.h"
#include "errmsg.h"

/*
 * Given a terminal or non-terminal symbol code,
 * allocate a parse tree node for it.
 * THE REST OF THE INITIALIZATION DEPENDS ON THE CALLER.
 */
struct node * treenode(int symbol)
{
   struct node *p = (struct node *)calloc(1, sizeof(struct node));
   if (p == NULL) stop("out of memory in treenode constructor");
   p->symbol = symbol;
   return p;
}

struct node * alcleaf(int symbol, char *lexeme)
{
   struct node * ret = treenode(symbol);
   ret->u.t.lexeme = strdup(lexeme);
   return ret;
}

struct node * alcternary(int symbol, int prodrule, struct node *k1,
			 struct node *k2, struct node *k3)
{
   struct node *rv = treenode(symbol);
   rv->u.nt.production_rule = prodrule;
   rv->u.nt.child[0] = k1;
   rv->u.nt.child[1] = k2;
   rv->u.nt.child[2] = k3;
   return rv;
}

struct node * alcnary(int symbol, int prodrule, int nkids, ...)
{
   int i;
   va_list mylist;
   struct node *rv = treenode(symbol);
   rv->u.nt.production_rule = prodrule;
   va_start(mylist, nkids);
   for(i=0; i<nkids; i++) {
      rv->u.nt.child[i] = va_arg(mylist, struct node *);
      printf("set child %d to %p\n", rv->u.nt.child[i]);
      }
   va_end(mylist);
   return rv;
}

void treeprint(struct node *np)
{
/* printf("treeprint %p\n", np); */
   /*
    * avoid segfault if something horrible went wrong.
    */
   if (np == NULL) { warn("NULL tree pointer"); return; }

/* printf("treeprint symbol %d\n", np->symbol); */
   if (np->symbol < 1000) {
      printf("%s", np->u.t.lexeme); fflush(stdout);
      }
   else {
      int i;
/* printf("treeprint child 0 %d\n", np->u.nt.child[0]); */
      for (i=0; np->u.nt.child[i] != NULL; i++ ) {
	 treeprint(np->u.nt.child[i]);
	 }
      }

   /* .... now what? */
}