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import argparse
import curses
import importlib
import sys
from tokenize import generate_tokens
from story6.parser import Parser
from story6.tokenizer import Tokenizer
from story6.visualizer import Visualizer
argparser = argparse.ArgumentParser()
argparser.add_argument("program", nargs="?", default="story6/in.txt", help="Sample program (in.txt)")
argparser.add_argument("-g", "--grammar", default="story6.toy.ToyParser", help="Grammar class (ToyParser)")
argparser.add_argument("-s", "--start", default="start", help="Start symbol (start)")
argparser.add_argument("-q", "--quiet", action="store_true", help="Don't use visualizer")
def main():
args = argparser.parse_args()
filename = args.program
startname = args.start
modname, classname = args.grammar.rsplit(".", 1)
try:
mod = importlib.import_module(modname)
except ImportError:
sys.exit(f"Cannot import {modname}")
try:
cls = getattr(mod, classname)
except AttributeError:
sys.exit(f"Module {modname} has no attribute {classname}")
if not isinstance(cls, type):
sys.exit(f"Object {modname}.{classname} is not a class ({cls!r})")
if not issubclass(cls, Parser):
sys.exit(f"Object {modname}.{classname} is not a subclass of Parser")
tree = None
with open(filename) as f:
tokengen = generate_tokens(f.readline)
if args.quiet:
vis = None
else:
vis = Visualizer()
try:
tok = Tokenizer(tokengen, vis)
p = cls(tok)
start = getattr(p, startname)
tree = start()
if vis:
vis.done()
finally:
if vis:
vis.close()
if tree:
print(tree)
else:
if tok.tokens:
last = tok.tokens[-1]
print(f"Line {last.start[0]}:")
print(last.line)
print(" "*last.start[1] + "^")
sys.exit("SyntaxError")
main()
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