/*------------------------------------------------------------------*/
/* circuit.h                                                        */
/*------------------------------------------------------------------*/

#ifndef CIRCUIT_INCLUDED
#define CIRCUIT_INCLUDED

#include "expr.h"

enum SymbolType {FLIPFLOP_SYMBOL, INPUT_SYMBOL, UNKNOWN_SYMBOL};

/* These functions are called by the Parser: */

int Circuit_declareInput(char *pcName);
/* If pcName was previously declared as a Circuit input name or as a 
   Circuit flip flop name, then return 0 (FALSE).  Otherwise, record
   pcName as a Circuit input name and return 1 (TRUE).  It is a 
   checked runtime error for pcName to be NULL. */
  
int Circuit_declareFlipFlop(char *pcName);
/* If pcName was previously declared as a Circuit flip flop name or 
   as a Circuit input, then return 0 (FALSE).  Otherwise, record 
   pcName as a Circuit flip flop name, and return 1 (TRUE).  It is 
   a checked runtime error for pcName to be NULL. */

enum SymbolType Circuit_getSymbolType(char *pcName);
/* Return FLIPFLOP_SYMBOL if pcName is the name of a Circuit flip
   flop, INPUT_SYMBOL if pcName is the name of a Circuit input, or
   UNKNOWN_SYMBOL if pcName the name of neither a Circuit flip flop
   nor a Circuit input.  It is a checked runtime error for pcName to 
   be NULL. */

int Circuit_getFlipFlopIndex(char *pcName);
/* Return the (zero-based) index of the Circuit flip flop whose name 
   is pcName, or -1 if there is no such Circuit flip flop.  It is a 
   checked runtime error for pcName to be NULL. */
 
int Circuit_getInputIndex(char *pcName);
/* Return the (zero-based) index of the Circuit input whose name is 
   pcName, or -1 if there is no such Circuit input.  It is a checked 
   runtime error for pcName to be NULL. */

int Circuit_defineFlipFlop(int iIndex, Expr_T oExpr);
/* If the Circuit flip flop whose index is iIndex is already defined,
   then return 0 (FALSE).  Otherwise, record oExpr as the definition 
   of the Circuit flip flop whose index is iIndex, and return 1 
   (TRUE).  It is a checked runtime error for iIndex to be negative 
   or for oExpr to be NULL. */

char *Circuit_findUndefinedFlipFlop(void);
/* Return the name of the first declared Circuit flip flop that has 
   not been defined, or NULL if there is no undefined Circuit flip
   flop. */

void Circuit_complete(void);
/* The Parser is finished parsing the Circuit description, so do 
   whatever (if any) work is required to complete the Circuit 
   internal form. */

#endif