import reader
import sys

def main():
	print("Welcome to the lisp interpreter! REPL expression results will be stored in an output file, output.txt by default. This can be overridden by passing an argument to the program.\n"
		  "Enter (quit) to exit the program. Supported functionality includes mathematical operations, conditional statements, variables, user-defined functions, logical operations, and list manipulation.")
	outputfile = "output.txt" if len(sys.argv) == 1 else sys.argv[1]
	interpreter = reader.Reader(outputfile)
	# REPL Loop
	while True:
		try:
			expression: str = input("> ").upper()
		except KeyboardInterrupt:
			print("\n>> bye")
			return
		except EOFError:
			print("\n>> bye")
			return
		interpreter.tokenize(expression)
		interpreter.run()

if __name__ == "__main__":
	main()