class PyLox(object):
"""
Command-line runner to execute Lox source code. Provides an interface
to run as REPL prompt or on a pylox source file.
"""
def __init__(self, verbose=False):
self.verbose = verbose
self.interpreter = Interpreter(self.verbose)
def run_prompt(self):
while True:
source = input(PYLOX_PROMPT)
self.try_read_and_evaluate(source)
def run_file(self, path):
with open(path) as f:
source = f.read()
self.try_read_and_evaluate(source)
def try_read_and_evaluate(self, source):
tokens = Scanner(source, verbose=self.verbose).scan_tokens()
if self.verbose:
print(" tokens -> {}".format(tokens))
parser = Parser(tokens)
try:
statements = parser.parse()
except Exception as e:
print("Error parsing statements: {}".format(e))
return
if self.verbose:
print(" statements -> {}".format(statements))
self.interpreter.interpret(statements)
class Lox:
""" Lox class"""
def __init__(self):
self.had_error = False
self.had_runtime_error = False
self.interpreter = Interpreter()
def run_file(self, file):
""" Runs file
:param file: input file
"""
with open(file) as content:
program = content.read()
self.run(program)
if self.had_error:
sys.exit(65)
elif self.had_runtime_error:
sys.exit(70)
def run_prompt(self):
""" Runs prompt """
print("Running prompt")
while True:
line = input(">> ")
self.run(line)
# If we had an error, we should reset at new prompt
self.had_error = False
self.had_runtime_error = False
def run(self, line):
""" Runs the input
:param line: line to tokenize and eval
"""
scanner = Scanner(line)
tokens = scanner.scan_tokens()
parser = Parser(tokens, self.error)
statements = parser.parse()
self.interpreter.interpret(statements)
if self.had_error:
return
def error(self, line, message):
""" error
:param line: the location of error
:param message: error message
"""
self.report(line + " " + message)
def runtimeerror(self, error):
"""
set runtimeerror message
:param error: error message
:return: None
"""
error_message = "{0} \n [line {1}]".format(error.get_message(), error.token.line)
print(error_message)
self.had_runtime_error = True
def report(self, line, where=None, message=None):
""" error
:param line: line of error
:param where: location of error
:param: message: error message
"""
self.had_error = True
raise Exception("[Line {0}] Error {1}: {2} ".format(line, where, message))