25 lines
620 B
Python
25 lines
620 B
Python
#!/usr/bin/env python3
|
|
import sys
|
|
from calc.lexer import tokenize, LexError
|
|
from calc.parser import parse, ParseError
|
|
from calc.evaluator import evaluate, format_result, EvalError
|
|
|
|
|
|
def main():
|
|
if len(sys.argv) != 2:
|
|
print("usage: calc.py <expression>", file=sys.stderr)
|
|
sys.exit(1)
|
|
expr = sys.argv[1]
|
|
try:
|
|
tokens = tokenize(expr)
|
|
ast = parse(tokens)
|
|
result = evaluate(ast)
|
|
print(format_result(result))
|
|
except (LexError, ParseError, EvalError) as e:
|
|
print(f"error: {e}", file=sys.stderr)
|
|
sys.exit(1)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|