//
// main program for c++ versions of kamin interpreters
//

# include "environment.h"
# include "reader.h"

//	forward definitions
extern initialize();

//	definitions of global environments

Env globalEnvironment;		// global symbols
Env valueOps;			// built-in operations
Env commands;			// top level commands

List emptyList;

//	the following globals are defined in the ``initialization'' routine
ReaderClass * reader;
Expr true;
Expr false;

main() {
	Expr entered;	// expression as entered by users

	// common initialization
	emptyList = new ListNode(0, 0);
	globalEnvironment = new Environment(emptyList, emptyList, 0);
	valueOps = new Environment(emptyList, emptyList, 0);
	commands = new Environment(emptyList, emptyList, valueOps);

	// interpreter-specific initialization
	initialize();

	// now the read-eval-print loop
	while (1) {
		entered = reader->promptAndRead();

		// now see if expression is quit
		Symbol * sym = entered()->isSymbol();
		if (sym && (*sym == "quit"))
			break;

		// nothing else, must just be an expression
		entered.evalAndPrint(commands, globalEnvironment);
		}
}