Source code for brewtils.choices

# -*- coding: utf-8 -*-

from lark import Lark, Transformer

# Lark added some new errors in later versions
# Lark also moved around their error in 0.6.0
    from lark import ParseError
except ImportError:
    from lark.common import ParseError

    from lark import GrammarError, LexError
except ImportError:
    GrammarError = ParseError
    LexError = ParseError

choices_grammar = r"""
    func: CNAME [func_args]
    url: ADDRESS [url_args]
    reference: ref

    func_args: "(" [arg_pair ("," arg_pair)*] ")"
    url_args: "?" arg_pair ("&" arg_pair)*

    arg_pair: CNAME "=" ref
    ?ref: "${" CNAME "}"

    ADDRESS: /^http[^\?]*/

    %import common.CNAME
    %import common.WS
    %ignore WS

parsers = {
    "func": Lark(choices_grammar, start="func"),
    "url": Lark(choices_grammar, start="url"),
    "reference": Lark(choices_grammar, start="reference"),

[docs]class FunctionTransformer(Transformer):
[docs] @staticmethod def func(s): return {"name": str(s[0]), "args": s[1] if len(s) > 1 else []}
[docs] @staticmethod def url(s): return {"address": str(s[0]), "args": s[1] if len(s) > 1 else []}
[docs] @staticmethod def reference(s): return str(s[0])
[docs] @staticmethod def arg_pair(s): return str(s[0]), str(s[1])
func_args = list url_args = list
[docs]def parse(input_string, parse_as=None): """Attempt to parse a string into a choices dictionary. :param input_string: The string to parse :param parse_as: String specifying how to parse `input_string`. Valid values are 'func' or 'url'. Will try all valid values if None. :return: A dictionary containing the results of the parse :raise lark.common.ParseError: The parser was not able to find a valid parsing of `input_string` """ def _parse(_input_string, _parser): try: return FunctionTransformer().transform(_parser.parse(_input_string)) except (GrammarError, LexError, ParseError) as e: raise ParseError(e) if parse_as is not None: return _parse(input_string, parsers[parse_as]) else: for parser in parsers.values(): try: return _parse(input_string, parser) except ParseError: continue raise ParseError('Unable to successfully parse input "%s"' % input_string)