Mapytex/mapytex/calculus/core/operator.py

46 lines
940 B
Python

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2017 lafrite <lafrite@Poivre>
#
# Distributed under terms of the MIT license.
__all__ = ["OperatorError", "OPERATORS", "is_operator"]
class OperatorError(Exception):
pass
OPERATORS = {
"+": {"repr": "+", "arity": 2, "precedence": 0},
"-": {"repr": "-", "arity": 1, "precedence": 1},
"*": {"repr": "*", "arity": 2, "precedence": 2},
"/": {"repr": "/", "arity": 2, "precedence": 3},
"^": {"repr": "^", "arity": 2, "precedence": 4},
}
def is_operator(string):
""" Return whether a string is an operator or not
:param string: string to test
:returns: boolean
:example:
>>> is_operator("+")
True
>>> is_operator("i")
False
"""
return string in OPERATORS.keys()
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