Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/jmespath/__init__.py

@@ -0,0 +1,23 @@
+import warnings
+import sys
+from jmespath import parser
+from jmespath.visitor import Options
+
+__version__ = '0.10.0'
+
+
+if sys.version_info[:2] <= (2, 6) or ((3, 0) <= sys.version_info[:2] <= (3, 3)):
+    python_ver = '.'.join(str(x) for x in sys.version_info[:3])
+
+    warnings.warn(
+        'You are using Python {0}, which will no longer be supported in '
+        'version 0.11.0'.format(python_ver),
+        DeprecationWarning)
+
+
+def compile(expression):
+    return parser.Parser().parse(expression)
+
+
+def search(expression, data, options=None):
+    return parser.Parser().parse(expression).search(data, options=options)

venv/lib/python3.9/site-packages/jmespath/ast.py

@@ -0,0 +1,90 @@
+# AST nodes have this structure:
+# {"type": <node type>", children: [], "value": ""}
+
+
+def comparator(name, first, second):
+    return {'type': 'comparator', 'children': [first, second], 'value': name}
+
+
+def current_node():
+    return {'type': 'current', 'children': []}
+
+
+def expref(expression):
+    return {'type': 'expref', 'children': [expression]}
+
+
+def function_expression(name, args):
+    return {'type': 'function_expression', 'children': args, 'value': name}
+
+
+def field(name):
+    return {"type": "field", "children": [], "value": name}
+
+
+def filter_projection(left, right, comparator):
+    return {'type': 'filter_projection', 'children': [left, right, comparator]}
+
+
+def flatten(node):
+    return {'type': 'flatten', 'children': [node]}
+
+
+def identity():
+    return {"type": "identity", 'children': []}
+
+
+def index(index):
+    return {"type": "index", "value": index, "children": []}
+
+
+def index_expression(children):
+    return {"type": "index_expression", 'children': children}
+
+
+def key_val_pair(key_name, node):
+    return {"type": "key_val_pair", 'children': [node], "value": key_name}
+
+
+def literal(literal_value):
+    return {'type': 'literal', 'value': literal_value, 'children': []}
+
+
+def multi_select_dict(nodes):
+    return {"type": "multi_select_dict", "children": nodes}
+
+
+def multi_select_list(nodes):
+    return {"type": "multi_select_list", "children": nodes}
+
+
+def or_expression(left, right):
+    return {"type": "or_expression", "children": [left, right]}
+
+
+def and_expression(left, right):
+    return {"type": "and_expression", "children": [left, right]}
+
+
+def not_expression(expr):
+    return {"type": "not_expression", "children": [expr]}
+
+
+def pipe(left, right):
+    return {'type': 'pipe', 'children': [left, right]}
+
+
+def projection(left, right):
+    return {'type': 'projection', 'children': [left, right]}
+
+
+def subexpression(children):
+    return {"type": "subexpression", 'children': children}
+
+
+def slice(start, end, step):
+    return {"type": "slice", "children": [start, end, step]}
+
+
+def value_projection(left, right):
+    return {'type': 'value_projection', 'children': [left, right]}

venv/lib/python3.9/site-packages/jmespath/compat.py

@@ -0,0 +1,65 @@
+import sys
+import inspect
+
+PY2 = sys.version_info[0] == 2
+
+
+def with_metaclass(meta, *bases):
+    # Taken from flask/six.
+    class metaclass(meta):
+        def __new__(cls, name, this_bases, d):
+            return meta(name, bases, d)
+    return type.__new__(metaclass, 'temporary_class', (), {})
+
+
+if PY2:
+    text_type = unicode
+    string_type = basestring
+    from itertools import izip_longest as zip_longest
+
+    def with_str_method(cls):
+        """Class decorator that handles __str__ compat between py2 and py3."""
+        # In python2, the __str__ should be __unicode__
+        # and __str__ should return bytes.
+        cls.__unicode__ = cls.__str__
+        def __str__(self):
+            return self.__unicode__().encode('utf-8')
+        cls.__str__ = __str__
+        return cls
+
+    def with_repr_method(cls):
+        """Class decorator that handle __repr__ with py2 and py3."""
+        # This is almost the same thing as with_str_method *except*
+        # it uses the unicode_escape encoding.  This also means we need to be
+        # careful encoding the input multiple times, so we only encode
+        # if we get a unicode type.
+        original_repr_method = cls.__repr__
+        def __repr__(self):
+            original_repr = original_repr_method(self)
+            if isinstance(original_repr, text_type):
+                original_repr = original_repr.encode('unicode_escape')
+            return original_repr
+        cls.__repr__ = __repr__
+        return cls
+
+    def get_methods(cls):
+        for name, method in inspect.getmembers(cls,
+                                               predicate=inspect.ismethod):
+            yield name, method
+
+else:
+    text_type = str
+    string_type = str
+    from itertools import zip_longest
+
+    def with_str_method(cls):
+        # In python3, we don't need to do anything, we return a str type.
+        return cls
+
+    def with_repr_method(cls):
+        return cls
+
+    def get_methods(cls):
+        for name, method in inspect.getmembers(cls,
+                                               predicate=inspect.isfunction):
+            yield name, method

venv/lib/python3.9/site-packages/jmespath/exceptions.py

@@ -0,0 +1,122 @@
+from jmespath.compat import with_str_method
+
+
+class JMESPathError(ValueError):
+    pass
+
+
+@with_str_method
+class ParseError(JMESPathError):
+    _ERROR_MESSAGE = 'Invalid jmespath expression'
+    def __init__(self, lex_position, token_value, token_type,
+                 msg=_ERROR_MESSAGE):
+        super(ParseError, self).__init__(lex_position, token_value, token_type)
+        self.lex_position = lex_position
+        self.token_value = token_value
+        self.token_type = token_type.upper()
+        self.msg = msg
+        # Whatever catches the ParseError can fill in the full expression
+        self.expression = None
+
+    def __str__(self):
+        # self.lex_position +1 to account for the starting double quote char.
+        underline = ' ' * (self.lex_position + 1) + '^'
+        return (
+            '%s: Parse error at column %s, '
+            'token "%s" (%s), for expression:\n"%s"\n%s' % (
+                self.msg, self.lex_position, self.token_value, self.token_type,
+                self.expression, underline))
+
+
+@with_str_method
+class IncompleteExpressionError(ParseError):
+    def set_expression(self, expression):
+        self.expression = expression
+        self.lex_position = len(expression)
+        self.token_type = None
+        self.token_value = None
+
+    def __str__(self):
+        # self.lex_position +1 to account for the starting double quote char.
+        underline = ' ' * (self.lex_position + 1) + '^'
+        return (
+            'Invalid jmespath expression: Incomplete expression:\n'
+            '"%s"\n%s' % (self.expression, underline))
+
+
+@with_str_method
+class LexerError(ParseError):
+    def __init__(self, lexer_position, lexer_value, message, expression=None):
+        self.lexer_position = lexer_position
+        self.lexer_value = lexer_value
+        self.message = message
+        super(LexerError, self).__init__(lexer_position,
+                                         lexer_value,
+                                         message)
+        # Whatever catches LexerError can set this.
+        self.expression = expression
+
+    def __str__(self):
+        underline = ' ' * self.lexer_position + '^'
+        return 'Bad jmespath expression: %s:\n%s\n%s' % (
+            self.message, self.expression, underline)
+
+
+@with_str_method
+class ArityError(ParseError):
+    def __init__(self, expected, actual, name):
+        self.expected_arity = expected
+        self.actual_arity = actual
+        self.function_name = name
+        self.expression = None
+
+    def __str__(self):
+        return ("Expected %s %s for function %s(), "
+                "received %s" % (
+                    self.expected_arity,
+                    self._pluralize('argument', self.expected_arity),
+                    self.function_name,
+                    self.actual_arity))
+
+    def _pluralize(self, word, count):
+        if count == 1:
+            return word
+        else:
+            return word + 's'
+
+
+@with_str_method
+class VariadictArityError(ArityError):
+    def __str__(self):
+        return ("Expected at least %s %s for function %s(), "
+                "received %s" % (
+                    self.expected_arity,
+                    self._pluralize('argument', self.expected_arity),
+                    self.function_name,
+                    self.actual_arity))
+
+
+@with_str_method
+class JMESPathTypeError(JMESPathError):
+    def __init__(self, function_name, current_value, actual_type,
+                 expected_types):
+        self.function_name = function_name
+        self.current_value = current_value
+        self.actual_type = actual_type
+        self.expected_types = expected_types
+
+    def __str__(self):
+        return ('In function %s(), invalid type for value: %s, '
+                'expected one of: %s, received: "%s"' % (
+                    self.function_name, self.current_value,
+                    self.expected_types, self.actual_type))
+
+
+class EmptyExpressionError(JMESPathError):
+    def __init__(self):
+        super(EmptyExpressionError, self).__init__(
+            "Invalid JMESPath expression: cannot be empty.")
+
+
+class UnknownFunctionError(JMESPathError):
+    pass

venv/lib/python3.9/site-packages/jmespath/functions.py

@@ -0,0 +1,362 @@
+import math
+import json
+
+from jmespath import exceptions
+from jmespath.compat import string_type as STRING_TYPE
+from jmespath.compat import get_methods, with_metaclass
+
+
+# python types -> jmespath types
+TYPES_MAP = {
+    'bool': 'boolean',
+    'list': 'array',
+    'dict': 'object',
+    'NoneType': 'null',
+    'unicode': 'string',
+    'str': 'string',
+    'float': 'number',
+    'int': 'number',
+    'long': 'number',
+    'OrderedDict': 'object',
+    '_Projection': 'array',
+    '_Expression': 'expref',
+}
+
+
+# jmespath types -> python types
+REVERSE_TYPES_MAP = {
+    'boolean': ('bool',),
+    'array': ('list', '_Projection'),
+    'object': ('dict', 'OrderedDict',),
+    'null': ('NoneType',),
+    'string': ('unicode', 'str'),
+    'number': ('float', 'int', 'long'),
+    'expref': ('_Expression',),
+}
+
+
+def signature(*arguments):
+    def _record_signature(func):
+        func.signature = arguments
+        return func
+    return _record_signature
+
+
+class FunctionRegistry(type):
+    def __init__(cls, name, bases, attrs):
+        cls._populate_function_table()
+        super(FunctionRegistry, cls).__init__(name, bases, attrs)
+
+    def _populate_function_table(cls):
+        function_table = {}
+        # Any method with a @signature decorator that also
+        # starts with "_func_" is registered as a function.
+        # _func_max_by -> max_by function.
+        for name, method in get_methods(cls):
+            if not name.startswith('_func_'):
+                continue
+            signature = getattr(method, 'signature', None)
+            if signature is not None:
+                function_table[name[6:]] = {
+                    'function': method,
+                    'signature': signature,
+                }
+        cls.FUNCTION_TABLE = function_table
+
+
+class Functions(with_metaclass(FunctionRegistry, object)):
+
+    FUNCTION_TABLE = {
+    }
+
+    def call_function(self, function_name, resolved_args):
+        try:
+            spec = self.FUNCTION_TABLE[function_name]
+        except KeyError:
+            raise exceptions.UnknownFunctionError(
+                "Unknown function: %s()" % function_name)
+        function = spec['function']
+        signature = spec['signature']
+        self._validate_arguments(resolved_args, signature, function_name)
+        return function(self, *resolved_args)
+
+    def _validate_arguments(self, args, signature, function_name):
+        if signature and signature[-1].get('variadic'):
+            if len(args) < len(signature):
+                raise exceptions.VariadictArityError(
+                    len(signature), len(args), function_name)
+        elif len(args) != len(signature):
+            raise exceptions.ArityError(
+                len(signature), len(args), function_name)
+        return self._type_check(args, signature, function_name)
+
+    def _type_check(self, actual, signature, function_name):
+        for i in range(len(signature)):
+            allowed_types = signature[i]['types']
+            if allowed_types:
+                self._type_check_single(actual[i], allowed_types,
+                                        function_name)
+
+    def _type_check_single(self, current, types, function_name):
+        # Type checking involves checking the top level type,
+        # and in the case of arrays, potentially checking the types
+        # of each element.
+        allowed_types, allowed_subtypes = self._get_allowed_pytypes(types)
+        # We're not using isinstance() on purpose.
+        # The type model for jmespath does not map
+        # 1-1 with python types (booleans are considered
+        # integers in python for example).
+        actual_typename = type(current).__name__
+        if actual_typename not in allowed_types:
+            raise exceptions.JMESPathTypeError(
+                function_name, current,
+                self._convert_to_jmespath_type(actual_typename), types)
+        # If we're dealing with a list type, we can have
+        # additional restrictions on the type of the list
+        # elements (for example a function can require a
+        # list of numbers or a list of strings).
+        # Arrays are the only types that can have subtypes.
+        if allowed_subtypes:
+            self._subtype_check(current, allowed_subtypes,
+                                types, function_name)
+
+    def _get_allowed_pytypes(self, types):
+        allowed_types = []
+        allowed_subtypes = []
+        for t in types:
+            type_ = t.split('-', 1)
+            if len(type_) == 2:
+                type_, subtype = type_
+                allowed_subtypes.append(REVERSE_TYPES_MAP[subtype])
+            else:
+                type_ = type_[0]
+            allowed_types.extend(REVERSE_TYPES_MAP[type_])
+        return allowed_types, allowed_subtypes
+
+    def _subtype_check(self, current, allowed_subtypes, types, function_name):
+        if len(allowed_subtypes) == 1:
+            # The easy case, we know up front what type
+            # we need to validate.
+            allowed_subtypes = allowed_subtypes[0]
+            for element in current:
+                actual_typename = type(element).__name__
+                if actual_typename not in allowed_subtypes:
+                    raise exceptions.JMESPathTypeError(
+                        function_name, element, actual_typename, types)
+        elif len(allowed_subtypes) > 1 and current:
+            # Dynamic type validation.  Based on the first
+            # type we see, we validate that the remaining types
+            # match.
+            first = type(current[0]).__name__
+            for subtypes in allowed_subtypes:
+                if first in subtypes:
+                    allowed = subtypes
+                    break
+            else:
+                raise exceptions.JMESPathTypeError(
+                    function_name, current[0], first, types)
+            for element in current:
+                actual_typename = type(element).__name__
+                if actual_typename not in allowed:
+                    raise exceptions.JMESPathTypeError(
+                        function_name, element, actual_typename, types)
+
+    @signature({'types': ['number']})
+    def _func_abs(self, arg):
+        return abs(arg)
+
+    @signature({'types': ['array-number']})
+    def _func_avg(self, arg):
+        if arg:
+            return sum(arg) / float(len(arg))
+        else:
+            return None
+
+    @signature({'types': [], 'variadic': True})
+    def _func_not_null(self, *arguments):
+        for argument in arguments:
+            if argument is not None:
+                return argument
+
+    @signature({'types': []})
+    def _func_to_array(self, arg):
+        if isinstance(arg, list):
+            return arg
+        else:
+            return [arg]
+
+    @signature({'types': []})
+    def _func_to_string(self, arg):
+        if isinstance(arg, STRING_TYPE):
+            return arg
+        else:
+            return json.dumps(arg, separators=(',', ':'),
+                              default=str)
+
+    @signature({'types': []})
+    def _func_to_number(self, arg):
+        if isinstance(arg, (list, dict, bool)):
+            return None
+        elif arg is None:
+            return None
+        elif isinstance(arg, (int, float)):
+            return arg
+        else:
+            try:
+                return int(arg)
+            except ValueError:
+                try:
+                    return float(arg)
+                except ValueError:
+                    return None
+
+    @signature({'types': ['array', 'string']}, {'types': []})
+    def _func_contains(self, subject, search):
+        return search in subject
+
+    @signature({'types': ['string', 'array', 'object']})
+    def _func_length(self, arg):
+        return len(arg)
+
+    @signature({'types': ['string']}, {'types': ['string']})
+    def _func_ends_with(self, search, suffix):
+        return search.endswith(suffix)
+
+    @signature({'types': ['string']}, {'types': ['string']})
+    def _func_starts_with(self, search, suffix):
+        return search.startswith(suffix)
+
+    @signature({'types': ['array', 'string']})
+    def _func_reverse(self, arg):
+        if isinstance(arg, STRING_TYPE):
+            return arg[::-1]
+        else:
+            return list(reversed(arg))
+
+    @signature({"types": ['number']})
+    def _func_ceil(self, arg):
+        return math.ceil(arg)
+
+    @signature({"types": ['number']})
+    def _func_floor(self, arg):
+        return math.floor(arg)
+
+    @signature({"types": ['string']}, {"types": ['array-string']})
+    def _func_join(self, separator, array):
+        return separator.join(array)
+
+    @signature({'types': ['expref']}, {'types': ['array']})
+    def _func_map(self, expref, arg):
+        result = []
+        for element in arg:
+            result.append(expref.visit(expref.expression, element))
+        return result
+
+    @signature({"types": ['array-number', 'array-string']})
+    def _func_max(self, arg):
+        if arg:
+            return max(arg)
+        else:
+            return None
+
+    @signature({"types": ["object"], "variadic": True})
+    def _func_merge(self, *arguments):
+        merged = {}
+        for arg in arguments:
+            merged.update(arg)
+        return merged
+
+    @signature({"types": ['array-number', 'array-string']})
+    def _func_min(self, arg):
+        if arg:
+            return min(arg)
+        else:
+            return None
+
+    @signature({"types": ['array-string', 'array-number']})
+    def _func_sort(self, arg):
+        return list(sorted(arg))
+
+    @signature({"types": ['array-number']})
+    def _func_sum(self, arg):
+        return sum(arg)
+
+    @signature({"types": ['object']})
+    def _func_keys(self, arg):
+        # To be consistent with .values()
+        # should we also return the indices of a list?
+        return list(arg.keys())
+
+    @signature({"types": ['object']})
+    def _func_values(self, arg):
+        return list(arg.values())
+
+    @signature({'types': []})
+    def _func_type(self, arg):
+        if isinstance(arg, STRING_TYPE):
+            return "string"
+        elif isinstance(arg, bool):
+            return "boolean"
+        elif isinstance(arg, list):
+            return "array"
+        elif isinstance(arg, dict):
+            return "object"
+        elif isinstance(arg, (float, int)):
+            return "number"
+        elif arg is None:
+            return "null"
+
+    @signature({'types': ['array']}, {'types': ['expref']})
+    def _func_sort_by(self, array, expref):
+        if not array:
+            return array
+        # sort_by allows for the expref to be either a number of
+        # a string, so we have some special logic to handle this.
+        # We evaluate the first array element and verify that it's
+        # either a string of a number.  We then create a key function
+        # that validates that type, which requires that remaining array
+        # elements resolve to the same type as the first element.
+        required_type = self._convert_to_jmespath_type(
+            type(expref.visit(expref.expression, array[0])).__name__)
+        if required_type not in ['number', 'string']:
+            raise exceptions.JMESPathTypeError(
+                'sort_by', array[0], required_type, ['string', 'number'])
+        keyfunc = self._create_key_func(expref,
+                                        [required_type],
+                                        'sort_by')
+        return list(sorted(array, key=keyfunc))
+
+    @signature({'types': ['array']}, {'types': ['expref']})
+    def _func_min_by(self, array, expref):
+        keyfunc = self._create_key_func(expref,
+                                        ['number', 'string'],
+                                        'min_by')
+        if array:
+            return min(array, key=keyfunc)
+        else:
+            return None
+
+    @signature({'types': ['array']}, {'types': ['expref']})
+    def _func_max_by(self, array, expref):
+        keyfunc = self._create_key_func(expref,
+                                        ['number', 'string'],
+                                        'max_by')
+        if array:
+            return max(array, key=keyfunc)
+        else:
+            return None
+
+    def _create_key_func(self, expref, allowed_types, function_name):
+        def keyfunc(x):
+            result = expref.visit(expref.expression, x)
+            actual_typename = type(result).__name__
+            jmespath_type = self._convert_to_jmespath_type(actual_typename)
+            # allowed_types is in term of jmespath types, not python types.
+            if jmespath_type not in allowed_types:
+                raise exceptions.JMESPathTypeError(
+                    function_name, result, jmespath_type, allowed_types)
+            return result
+        return keyfunc
+
+    def _convert_to_jmespath_type(self, pyobject):
+        return TYPES_MAP.get(pyobject, 'unknown')

venv/lib/python3.9/site-packages/jmespath/lexer.py

@@ -0,0 +1,208 @@
+import string
+import warnings
+from json import loads
+
+from jmespath.exceptions import LexerError, EmptyExpressionError
+
+
+class Lexer(object):
+    START_IDENTIFIER = set(string.ascii_letters + '_')
+    VALID_IDENTIFIER = set(string.ascii_letters + string.digits + '_')
+    VALID_NUMBER = set(string.digits)
+    WHITESPACE = set(" \t\n\r")
+    SIMPLE_TOKENS = {
+        '.': 'dot',
+        '*': 'star',
+        ']': 'rbracket',
+        ',': 'comma',
+        ':': 'colon',
+        '@': 'current',
+        '(': 'lparen',
+        ')': 'rparen',
+        '{': 'lbrace',
+        '}': 'rbrace',
+    }
+
+    def tokenize(self, expression):
+        self._initialize_for_expression(expression)
+        while self._current is not None:
+            if self._current in self.SIMPLE_TOKENS:
+                yield {'type': self.SIMPLE_TOKENS[self._current],
+                       'value': self._current,
+                       'start': self._position, 'end': self._position + 1}
+                self._next()
+            elif self._current in self.START_IDENTIFIER:
+                start = self._position
+                buff = self._current
+                while self._next() in self.VALID_IDENTIFIER:
+                    buff += self._current
+                yield {'type': 'unquoted_identifier', 'value': buff,
+                       'start': start, 'end': start + len(buff)}
+            elif self._current in self.WHITESPACE:
+                self._next()
+            elif self._current == '[':
+                start = self._position
+                next_char = self._next()
+                if next_char == ']':
+                    self._next()
+                    yield {'type': 'flatten', 'value': '[]',
+                           'start': start, 'end': start + 2}
+                elif next_char == '?':
+                    self._next()
+                    yield {'type': 'filter', 'value': '[?',
+                           'start': start, 'end': start + 2}
+                else:
+                    yield {'type': 'lbracket', 'value': '[',
+                           'start': start, 'end': start + 1}
+            elif self._current == "'":
+                yield self._consume_raw_string_literal()
+            elif self._current == '|':
+                yield self._match_or_else('|', 'or', 'pipe')
+            elif self._current == '&':
+                yield self._match_or_else('&', 'and', 'expref')
+            elif self._current == '`':
+                yield self._consume_literal()
+            elif self._current in self.VALID_NUMBER:
+                start = self._position
+                buff = self._consume_number()
+                yield {'type': 'number', 'value': int(buff),
+                       'start': start, 'end': start + len(buff)}
+            elif self._current == '-':
+                # Negative number.
+                start = self._position
+                buff = self._consume_number()
+                if len(buff) > 1:
+                    yield {'type': 'number', 'value': int(buff),
+                           'start': start, 'end': start + len(buff)}
+                else:
+                    raise LexerError(lexer_position=start,
+                                     lexer_value=buff,
+                                     message="Unknown token '%s'" % buff)
+            elif self._current == '"':
+                yield self._consume_quoted_identifier()
+            elif self._current == '<':
+                yield self._match_or_else('=', 'lte', 'lt')
+            elif self._current == '>':
+                yield self._match_or_else('=', 'gte', 'gt')
+            elif self._current == '!':
+                yield self._match_or_else('=', 'ne', 'not')
+            elif self._current == '=':
+                if self._next() == '=':
+                    yield {'type': 'eq', 'value': '==',
+                        'start': self._position - 1, 'end': self._position}
+                    self._next()
+                else:
+                    if self._current is None:
+                        # If we're at the EOF, we never advanced
+                        # the position so we don't need to rewind
+                        # it back one location.
+                        position = self._position
+                    else:
+                        position = self._position - 1
+                    raise LexerError(
+                        lexer_position=position,
+                        lexer_value='=',
+                        message="Unknown token '='")
+            else:
+                raise LexerError(lexer_position=self._position,
+                                 lexer_value=self._current,
+                                 message="Unknown token %s" % self._current)
+        yield {'type': 'eof', 'value': '',
+               'start': self._length, 'end': self._length}
+
+    def _consume_number(self):
+        start = self._position
+        buff = self._current
+        while self._next() in self.VALID_NUMBER:
+            buff += self._current
+        return buff
+
+    def _initialize_for_expression(self, expression):
+        if not expression:
+            raise EmptyExpressionError()
+        self._position = 0
+        self._expression = expression
+        self._chars = list(self._expression)
+        self._current = self._chars[self._position]
+        self._length = len(self._expression)
+
+    def _next(self):
+        if self._position == self._length - 1:
+            self._current = None
+        else:
+            self._position += 1
+            self._current = self._chars[self._position]
+        return self._current
+
+    def _consume_until(self, delimiter):
+        # Consume until the delimiter is reached,
+        # allowing for the delimiter to be escaped with "\".
+        start = self._position
+        buff = ''
+        self._next()
+        while self._current != delimiter:
+            if self._current == '\\':
+                buff += '\\'
+                self._next()
+            if self._current is None:
+                # We're at the EOF.
+                raise LexerError(lexer_position=start,
+                                 lexer_value=self._expression[start:],
+                                 message="Unclosed %s delimiter" % delimiter)
+            buff += self._current
+            self._next()
+        # Skip the closing delimiter.
+        self._next()
+        return buff
+
+    def _consume_literal(self):
+        start = self._position
+        lexeme = self._consume_until('`').replace('\\`', '`')
+        try:
+            # Assume it is valid JSON and attempt to parse.
+            parsed_json = loads(lexeme)
+        except ValueError:
+            try:
+                # Invalid JSON values should be converted to quoted
+                # JSON strings during the JEP-12 deprecation period.
+                parsed_json = loads('"%s"' % lexeme.lstrip())
+                warnings.warn("deprecated string literal syntax",
+                              PendingDeprecationWarning)
+            except ValueError:
+                raise LexerError(lexer_position=start,
+                                 lexer_value=self._expression[start:],
+                                 message="Bad token %s" % lexeme)
+        token_len = self._position - start
+        return {'type': 'literal', 'value': parsed_json,
+                'start': start, 'end': token_len}
+
+    def _consume_quoted_identifier(self):
+        start = self._position
+        lexeme = '"' + self._consume_until('"') + '"'
+        try:
+            token_len = self._position - start
+            return {'type': 'quoted_identifier', 'value': loads(lexeme),
+                    'start': start, 'end': token_len}
+        except ValueError as e:
+            error_message = str(e).split(':')[0]
+            raise LexerError(lexer_position=start,
+                             lexer_value=lexeme,
+                             message=error_message)
+
+    def _consume_raw_string_literal(self):
+        start = self._position
+        lexeme = self._consume_until("'").replace("\\'", "'")
+        token_len = self._position - start
+        return {'type': 'literal', 'value': lexeme,
+                'start': start, 'end': token_len}
+
+    def _match_or_else(self, expected, match_type, else_type):
+        start = self._position
+        current = self._current
+        next_char = self._next()
+        if next_char == expected:
+            self._next()
+            return {'type': match_type, 'value': current + next_char,
+                    'start': start, 'end': start + 1}
+        return {'type': else_type, 'value': current,
+                'start': start, 'end': start}

venv/lib/python3.9/site-packages/jmespath/parser.py

@@ -0,0 +1,527 @@
+"""Top down operator precedence parser.
+
+This is an implementation of Vaughan R. Pratt's
+"Top Down Operator Precedence" parser.
+(http://dl.acm.org/citation.cfm?doid=512927.512931).
+
+These are some additional resources that help explain the
+general idea behind a Pratt parser:
+
+* http://effbot.org/zone/simple-top-down-parsing.htm
+* http://javascript.crockford.com/tdop/tdop.html
+
+A few notes on the implementation.
+
+* All the nud/led tokens are on the Parser class itself, and are dispatched
+  using getattr().  This keeps all the parsing logic contained to a single
+  class.
+* We use two passes through the data.  One to create a list of token,
+  then one pass through the tokens to create the AST.  While the lexer actually
+  yields tokens, we convert it to a list so we can easily implement two tokens
+  of lookahead.  A previous implementation used a fixed circular buffer, but it
+  was significantly slower.  Also, the average jmespath expression typically
+  does not have a large amount of token so this is not an issue.  And
+  interestingly enough, creating a token list first is actually faster than
+  consuming from the token iterator one token at a time.
+
+"""
+import random
+
+from jmespath import lexer
+from jmespath.compat import with_repr_method
+from jmespath import ast
+from jmespath import exceptions
+from jmespath import visitor
+
+
+class Parser(object):
+    BINDING_POWER = {
+        'eof': 0,
+        'unquoted_identifier': 0,
+        'quoted_identifier': 0,
+        'literal': 0,
+        'rbracket': 0,
+        'rparen': 0,
+        'comma': 0,
+        'rbrace': 0,
+        'number': 0,
+        'current': 0,
+        'expref': 0,
+        'colon': 0,
+        'pipe': 1,
+        'or': 2,
+        'and': 3,
+        'eq': 5,
+        'gt': 5,
+        'lt': 5,
+        'gte': 5,
+        'lte': 5,
+        'ne': 5,
+        'flatten': 9,
+        # Everything above stops a projection.
+        'star': 20,
+        'filter': 21,
+        'dot': 40,
+        'not': 45,
+        'lbrace': 50,
+        'lbracket': 55,
+        'lparen': 60,
+    }
+    # The maximum binding power for a token that can stop
+    # a projection.
+    _PROJECTION_STOP = 10
+    # The _MAX_SIZE most recent expressions are cached in
+    # _CACHE dict.
+    _CACHE = {}
+    _MAX_SIZE = 128
+
+    def __init__(self, lookahead=2):
+        self.tokenizer = None
+        self._tokens = [None] * lookahead
+        self._buffer_size = lookahead
+        self._index = 0
+
+    def parse(self, expression):
+        cached = self._CACHE.get(expression)
+        if cached is not None:
+            return cached
+        parsed_result = self._do_parse(expression)
+        self._CACHE[expression] = parsed_result
+        if len(self._CACHE) > self._MAX_SIZE:
+            self._free_cache_entries()
+        return parsed_result
+
+    def _do_parse(self, expression):
+        try:
+            return self._parse(expression)
+        except exceptions.LexerError as e:
+            e.expression = expression
+            raise
+        except exceptions.IncompleteExpressionError as e:
+            e.set_expression(expression)
+            raise
+        except exceptions.ParseError as e:
+            e.expression = expression
+            raise
+
+    def _parse(self, expression):
+        self.tokenizer = lexer.Lexer().tokenize(expression)
+        self._tokens = list(self.tokenizer)
+        self._index = 0
+        parsed = self._expression(binding_power=0)
+        if not self._current_token() == 'eof':
+            t = self._lookahead_token(0)
+            raise exceptions.ParseError(t['start'], t['value'], t['type'],
+                                        "Unexpected token: %s" % t['value'])
+        return ParsedResult(expression, parsed)
+
+    def _expression(self, binding_power=0):
+        left_token = self._lookahead_token(0)
+        self._advance()
+        nud_function = getattr(
+            self, '_token_nud_%s' % left_token['type'],
+            self._error_nud_token)
+        left = nud_function(left_token)
+        current_token = self._current_token()
+        while binding_power < self.BINDING_POWER[current_token]:
+            led = getattr(self, '_token_led_%s' % current_token, None)
+            if led is None:
+                error_token = self._lookahead_token(0)
+                self._error_led_token(error_token)
+            else:
+                self._advance()
+                left = led(left)
+                current_token = self._current_token()
+        return left
+
+    def _token_nud_literal(self, token):
+        return ast.literal(token['value'])
+
+    def _token_nud_unquoted_identifier(self, token):
+        return ast.field(token['value'])
+
+    def _token_nud_quoted_identifier(self, token):
+        field = ast.field(token['value'])
+        # You can't have a quoted identifier as a function
+        # name.
+        if self._current_token() == 'lparen':
+            t = self._lookahead_token(0)
+            raise exceptions.ParseError(
+                0, t['value'], t['type'],
+                'Quoted identifier not allowed for function names.')
+        return field
+
+    def _token_nud_star(self, token):
+        left = ast.identity()
+        if self._current_token() == 'rbracket':
+            right = ast.identity()
+        else:
+            right = self._parse_projection_rhs(self.BINDING_POWER['star'])
+        return ast.value_projection(left, right)
+
+    def _token_nud_filter(self, token):
+        return self._token_led_filter(ast.identity())
+
+    def _token_nud_lbrace(self, token):
+        return self._parse_multi_select_hash()
+
+    def _token_nud_lparen(self, token):
+        expression = self._expression()
+        self._match('rparen')
+        return expression
+
+    def _token_nud_flatten(self, token):
+        left = ast.flatten(ast.identity())
+        right = self._parse_projection_rhs(
+            self.BINDING_POWER['flatten'])
+        return ast.projection(left, right)
+
+    def _token_nud_not(self, token):
+        expr = self._expression(self.BINDING_POWER['not'])
+        return ast.not_expression(expr)
+
+    def _token_nud_lbracket(self, token):
+        if self._current_token() in ['number', 'colon']:
+            right = self._parse_index_expression()
+            # We could optimize this and remove the identity() node.
+            # We don't really need an index_expression node, we can
+            # just use emit an index node here if we're not dealing
+            # with a slice.
+            return self._project_if_slice(ast.identity(), right)
+        elif self._current_token() == 'star' and \
+                self._lookahead(1) == 'rbracket':
+            self._advance()
+            self._advance()
+            right = self._parse_projection_rhs(self.BINDING_POWER['star'])
+            return ast.projection(ast.identity(), right)
+        else:
+            return self._parse_multi_select_list()
+
+    def _parse_index_expression(self):
+        # We're here:
+        # [<current>
+        #  ^
+        #  | current token
+        if (self._lookahead(0) == 'colon' or
+                self._lookahead(1) == 'colon'):
+            return self._parse_slice_expression()
+        else:
+            # Parse the syntax [number]
+            node = ast.index(self._lookahead_token(0)['value'])
+            self._advance()
+            self._match('rbracket')
+            return node
+
+    def _parse_slice_expression(self):
+        # [start:end:step]
+        # Where start, end, and step are optional.
+        # The last colon is optional as well.
+        parts = [None, None, None]
+        index = 0
+        current_token = self._current_token()
+        while not current_token == 'rbracket' and index < 3:
+            if current_token == 'colon':
+                index += 1
+                if index == 3:
+                    self._raise_parse_error_for_token(
+                        self._lookahead_token(0), 'syntax error')
+                self._advance()
+            elif current_token == 'number':
+                parts[index] = self._lookahead_token(0)['value']
+                self._advance()
+            else:
+                self._raise_parse_error_for_token(
+                    self._lookahead_token(0), 'syntax error')
+            current_token = self._current_token()
+        self._match('rbracket')
+        return ast.slice(*parts)
+
+    def _token_nud_current(self, token):
+        return ast.current_node()
+
+    def _token_nud_expref(self, token):
+        expression = self._expression(self.BINDING_POWER['expref'])
+        return ast.expref(expression)
+
+    def _token_led_dot(self, left):
+        if not self._current_token() == 'star':
+            right = self._parse_dot_rhs(self.BINDING_POWER['dot'])
+            if left['type'] == 'subexpression':
+                left['children'].append(right)
+                return left
+            else:
+                return ast.subexpression([left, right])
+        else:
+            # We're creating a projection.
+            self._advance()
+            right = self._parse_projection_rhs(
+                self.BINDING_POWER['dot'])
+            return ast.value_projection(left, right)
+
+    def _token_led_pipe(self, left):
+        right = self._expression(self.BINDING_POWER['pipe'])
+        return ast.pipe(left, right)
+
+    def _token_led_or(self, left):
+        right = self._expression(self.BINDING_POWER['or'])
+        return ast.or_expression(left, right)
+
+    def _token_led_and(self, left):
+        right = self._expression(self.BINDING_POWER['and'])
+        return ast.and_expression(left, right)
+
+    def _token_led_lparen(self, left):
+        if left['type'] != 'field':
+            #  0 - first func arg or closing paren.
+            # -1 - '(' token
+            # -2 - invalid function "name".
+            prev_t = self._lookahead_token(-2)
+            raise exceptions.ParseError(
+                prev_t['start'], prev_t['value'], prev_t['type'],
+                "Invalid function name '%s'" % prev_t['value'])
+        name = left['value']
+        args = []
+        while not self._current_token() == 'rparen':
+            expression = self._expression()
+            if self._current_token() == 'comma':
+                self._match('comma')
+            args.append(expression)
+        self._match('rparen')
+        function_node = ast.function_expression(name, args)
+        return function_node
+
+    def _token_led_filter(self, left):
+        # Filters are projections.
+        condition = self._expression(0)
+        self._match('rbracket')
+        if self._current_token() == 'flatten':
+            right = ast.identity()
+        else:
+            right = self._parse_projection_rhs(self.BINDING_POWER['filter'])
+        return ast.filter_projection(left, right, condition)
+
+    def _token_led_eq(self, left):
+        return self._parse_comparator(left, 'eq')
+
+    def _token_led_ne(self, left):
+        return self._parse_comparator(left, 'ne')
+
+    def _token_led_gt(self, left):
+        return self._parse_comparator(left, 'gt')
+
+    def _token_led_gte(self, left):
+        return self._parse_comparator(left, 'gte')
+
+    def _token_led_lt(self, left):
+        return self._parse_comparator(left, 'lt')
+
+    def _token_led_lte(self, left):
+        return self._parse_comparator(left, 'lte')
+
+    def _token_led_flatten(self, left):
+        left = ast.flatten(left)
+        right = self._parse_projection_rhs(
+            self.BINDING_POWER['flatten'])
+        return ast.projection(left, right)
+
+    def _token_led_lbracket(self, left):
+        token = self._lookahead_token(0)
+        if token['type'] in ['number', 'colon']:
+            right = self._parse_index_expression()
+            if left['type'] == 'index_expression':
+                # Optimization: if the left node is an index expr,
+                # we can avoid creating another node and instead just add
+                # the right node as a child of the left.
+                left['children'].append(right)
+                return left
+            else:
+                return self._project_if_slice(left, right)
+        else:
+            # We have a projection
+            self._match('star')
+            self._match('rbracket')
+            right = self._parse_projection_rhs(self.BINDING_POWER['star'])
+            return ast.projection(left, right)
+
+    def _project_if_slice(self, left, right):
+        index_expr = ast.index_expression([left, right])
+        if right['type'] == 'slice':
+            return ast.projection(
+                index_expr,
+                self._parse_projection_rhs(self.BINDING_POWER['star']))
+        else:
+            return index_expr
+
+    def _parse_comparator(self, left, comparator):
+        right = self._expression(self.BINDING_POWER[comparator])
+        return ast.comparator(comparator, left, right)
+
+    def _parse_multi_select_list(self):
+        expressions = []
+        while True:
+            expression = self._expression()
+            expressions.append(expression)
+            if self._current_token() == 'rbracket':
+                break
+            else:
+                self._match('comma')
+        self._match('rbracket')
+        return ast.multi_select_list(expressions)
+
+    def _parse_multi_select_hash(self):
+        pairs = []
+        while True:
+            key_token = self._lookahead_token(0)
+            # Before getting the token value, verify it's
+            # an identifier.
+            self._match_multiple_tokens(
+                token_types=['quoted_identifier', 'unquoted_identifier'])
+            key_name = key_token['value']
+            self._match('colon')
+            value = self._expression(0)
+            node = ast.key_val_pair(key_name=key_name, node=value)
+            pairs.append(node)
+            if self._current_token() == 'comma':
+                self._match('comma')
+            elif self._current_token() == 'rbrace':
+                self._match('rbrace')
+                break
+        return ast.multi_select_dict(nodes=pairs)
+
+    def _parse_projection_rhs(self, binding_power):
+        # Parse the right hand side of the projection.
+        if self.BINDING_POWER[self._current_token()] < self._PROJECTION_STOP:
+            # BP of 10 are all the tokens that stop a projection.
+            right = ast.identity()
+        elif self._current_token() == 'lbracket':
+            right = self._expression(binding_power)
+        elif self._current_token() == 'filter':
+            right = self._expression(binding_power)
+        elif self._current_token() == 'dot':
+            self._match('dot')
+            right = self._parse_dot_rhs(binding_power)
+        else:
+            self._raise_parse_error_for_token(self._lookahead_token(0),
+                                              'syntax error')
+        return right
+
+    def _parse_dot_rhs(self, binding_power):
+        # From the grammar:
+        # expression '.' ( identifier /
+        #                  multi-select-list /
+        #                  multi-select-hash /
+        #                  function-expression /
+        #                  *
+        # In terms of tokens that means that after a '.',
+        # you can have:
+        lookahead = self._current_token()
+        # Common case "foo.bar", so first check for an identifier.
+        if lookahead in ['quoted_identifier', 'unquoted_identifier', 'star']:
+            return self._expression(binding_power)
+        elif lookahead == 'lbracket':
+            self._match('lbracket')
+            return self._parse_multi_select_list()
+        elif lookahead == 'lbrace':
+            self._match('lbrace')
+            return self._parse_multi_select_hash()
+        else:
+            t = self._lookahead_token(0)
+            allowed = ['quoted_identifier', 'unquoted_identifier',
+                       'lbracket', 'lbrace']
+            msg = (
+                "Expecting: %s, got: %s" % (allowed, t['type'])
+            )
+            self._raise_parse_error_for_token(t, msg)
+
+    def _error_nud_token(self, token):
+        if token['type'] == 'eof':
+            raise exceptions.IncompleteExpressionError(
+                token['start'], token['value'], token['type'])
+        self._raise_parse_error_for_token(token, 'invalid token')
+
+    def _error_led_token(self, token):
+        self._raise_parse_error_for_token(token, 'invalid token')
+
+    def _match(self, token_type=None):
+        # inline'd self._current_token()
+        if self._current_token() == token_type:
+            # inline'd self._advance()
+            self._advance()
+        else:
+            self._raise_parse_error_maybe_eof(
+                token_type, self._lookahead_token(0))
+
+    def _match_multiple_tokens(self, token_types):
+        if self._current_token() not in token_types:
+            self._raise_parse_error_maybe_eof(
+                token_types, self._lookahead_token(0))
+        self._advance()
+
+    def _advance(self):
+        self._index += 1
+
+    def _current_token(self):
+        return self._tokens[self._index]['type']
+
+    def _lookahead(self, number):
+        return self._tokens[self._index + number]['type']
+
+    def _lookahead_token(self, number):
+        return self._tokens[self._index + number]
+
+    def _raise_parse_error_for_token(self, token, reason):
+        lex_position = token['start']
+        actual_value = token['value']
+        actual_type = token['type']
+        raise exceptions.ParseError(lex_position, actual_value,
+                                    actual_type, reason)
+
+    def _raise_parse_error_maybe_eof(self, expected_type, token):
+        lex_position = token['start']
+        actual_value = token['value']
+        actual_type = token['type']
+        if actual_type == 'eof':
+            raise exceptions.IncompleteExpressionError(
+                lex_position, actual_value, actual_type)
+        message = 'Expecting: %s, got: %s' % (expected_type,
+                                              actual_type)
+        raise exceptions.ParseError(
+            lex_position, actual_value, actual_type, message)
+
+    def _free_cache_entries(self):
+        for key in random.sample(self._CACHE.keys(), int(self._MAX_SIZE / 2)):
+            self._CACHE.pop(key, None)
+
+    @classmethod
+    def purge(cls):
+        """Clear the expression compilation cache."""
+        cls._CACHE.clear()
+
+
+@with_repr_method
+class ParsedResult(object):
+    def __init__(self, expression, parsed):
+        self.expression = expression
+        self.parsed = parsed
+
+    def search(self, value, options=None):
+        interpreter = visitor.TreeInterpreter(options)
+        result = interpreter.visit(self.parsed, value)
+        return result
+
+    def _render_dot_file(self):
+        """Render the parsed AST as a dot file.
+
+        Note that this is marked as an internal method because
+        the AST is an implementation detail and is subject
+        to change.  This method can be used to help troubleshoot
+        or for development purposes, but is not considered part
+        of the public supported API.  Use at your own risk.
+
+        """
+        renderer = visitor.GraphvizVisitor()
+        contents = renderer.visit(self.parsed)
+        return contents
+
+    def __repr__(self):
+        return repr(self.parsed)

venv/lib/python3.9/site-packages/jmespath/visitor.py

@@ -0,0 +1,328 @@
+import operator
+
+from jmespath import functions
+from jmespath.compat import string_type
+from numbers import Number
+
+
+def _equals(x, y):
+    if _is_special_integer_case(x, y):
+        return False
+    else:
+        return x == y
+
+
+def _is_special_integer_case(x, y):
+    # We need to special case comparing 0 or 1 to
+    # True/False.  While normally comparing any
+    # integer other than 0/1 to True/False will always
+    # return False.  However 0/1 have this:
+    # >>> 0 == True
+    # False
+    # >>> 0 == False
+    # True
+    # >>> 1 == True
+    # True
+    # >>> 1 == False
+    # False
+    #
+    # Also need to consider that:
+    # >>> 0 in [True, False]
+    # True
+    if type(x) is int and (x == 0 or x == 1):
+        return y is True or y is False
+    elif type(y) is int and (y == 0 or y == 1):
+        return x is True or x is False
+
+
+def _is_comparable(x):
+    # The spec doesn't officially support string types yet,
+    # but enough people are relying on this behavior that
+    # it's been added back.  This should eventually become
+    # part of the official spec.
+    return _is_actual_number(x) or isinstance(x, string_type)
+
+
+def _is_actual_number(x):
+    # We need to handle python's quirkiness with booleans,
+    # specifically:
+    #
+    # >>> isinstance(False, int)
+    # True
+    # >>> isinstance(True, int)
+    # True
+    if x is True or x is False:
+        return False
+    return isinstance(x, Number)
+
+
+class Options(object):
+    """Options to control how a JMESPath function is evaluated."""
+    def __init__(self, dict_cls=None, custom_functions=None):
+        #: The class to use when creating a dict.  The interpreter
+        #  may create dictionaries during the evaluation of a JMESPath
+        #  expression.  For example, a multi-select hash will
+        #  create a dictionary.  By default we use a dict() type.
+        #  You can set this value to change what dict type is used.
+        #  The most common reason you would change this is if you
+        #  want to set a collections.OrderedDict so that you can
+        #  have predictable key ordering.
+        self.dict_cls = dict_cls
+        self.custom_functions = custom_functions
+
+
+class _Expression(object):
+    def __init__(self, expression, interpreter):
+        self.expression = expression
+        self.interpreter = interpreter
+
+    def visit(self, node, *args, **kwargs):
+        return self.interpreter.visit(node, *args, **kwargs)
+
+
+class Visitor(object):
+    def __init__(self):
+        self._method_cache = {}
+
+    def visit(self, node, *args, **kwargs):
+        node_type = node['type']
+        method = self._method_cache.get(node_type)
+        if method is None:
+            method = getattr(
+                self, 'visit_%s' % node['type'], self.default_visit)
+            self._method_cache[node_type] = method
+        return method(node, *args, **kwargs)
+
+    def default_visit(self, node, *args, **kwargs):
+        raise NotImplementedError("default_visit")
+
+
+class TreeInterpreter(Visitor):
+    COMPARATOR_FUNC = {
+        'eq': _equals,
+        'ne': lambda x, y: not _equals(x, y),
+        'lt': operator.lt,
+        'gt': operator.gt,
+        'lte': operator.le,
+        'gte': operator.ge
+    }
+    _EQUALITY_OPS = ['eq', 'ne']
+    MAP_TYPE = dict
+
+    def __init__(self, options=None):
+        super(TreeInterpreter, self).__init__()
+        self._dict_cls = self.MAP_TYPE
+        if options is None:
+            options = Options()
+        self._options = options
+        if options.dict_cls is not None:
+            self._dict_cls = self._options.dict_cls
+        if options.custom_functions is not None:
+            self._functions = self._options.custom_functions
+        else:
+            self._functions = functions.Functions()
+
+    def default_visit(self, node, *args, **kwargs):
+        raise NotImplementedError(node['type'])
+
+    def visit_subexpression(self, node, value):
+        result = value
+        for node in node['children']:
+            result = self.visit(node, result)
+        return result
+
+    def visit_field(self, node, value):
+        try:
+            return value.get(node['value'])
+        except AttributeError:
+            return None
+
+    def visit_comparator(self, node, value):
+        # Common case: comparator is == or !=
+        comparator_func = self.COMPARATOR_FUNC[node['value']]
+        if node['value'] in self._EQUALITY_OPS:
+            return comparator_func(
+                self.visit(node['children'][0], value),
+                self.visit(node['children'][1], value)
+            )
+        else:
+            # Ordering operators are only valid for numbers.
+            # Evaluating any other type with a comparison operator
+            # will yield a None value.
+            left = self.visit(node['children'][0], value)
+            right = self.visit(node['children'][1], value)
+            num_types = (int, float)
+            if not (_is_comparable(left) and
+                    _is_comparable(right)):
+                return None
+            return comparator_func(left, right)
+
+    def visit_current(self, node, value):
+        return value
+
+    def visit_expref(self, node, value):
+        return _Expression(node['children'][0], self)
+
+    def visit_function_expression(self, node, value):
+        resolved_args = []
+        for child in node['children']:
+            current = self.visit(child, value)
+            resolved_args.append(current)
+        return self._functions.call_function(node['value'], resolved_args)
+
+    def visit_filter_projection(self, node, value):
+        base = self.visit(node['children'][0], value)
+        if not isinstance(base, list):
+            return None
+        comparator_node = node['children'][2]
+        collected = []
+        for element in base:
+            if self._is_true(self.visit(comparator_node, element)):
+                current = self.visit(node['children'][1], element)
+                if current is not None:
+                    collected.append(current)
+        return collected
+
+    def visit_flatten(self, node, value):
+        base = self.visit(node['children'][0], value)
+        if not isinstance(base, list):
+            # Can't flatten the object if it's not a list.
+            return None
+        merged_list = []
+        for element in base:
+            if isinstance(element, list):
+                merged_list.extend(element)
+            else:
+                merged_list.append(element)
+        return merged_list
+
+    def visit_identity(self, node, value):
+        return value
+
+    def visit_index(self, node, value):
+        # Even though we can index strings, we don't
+        # want to support that.
+        if not isinstance(value, list):
+            return None
+        try:
+            return value[node['value']]
+        except IndexError:
+            return None
+
+    def visit_index_expression(self, node, value):
+        result = value
+        for node in node['children']:
+            result = self.visit(node, result)
+        return result
+
+    def visit_slice(self, node, value):
+        if not isinstance(value, list):
+            return None
+        s = slice(*node['children'])
+        return value[s]
+
+    def visit_key_val_pair(self, node, value):
+        return self.visit(node['children'][0], value)
+
+    def visit_literal(self, node, value):
+        return node['value']
+
+    def visit_multi_select_dict(self, node, value):
+        if value is None:
+            return None
+        collected = self._dict_cls()
+        for child in node['children']:
+            collected[child['value']] = self.visit(child, value)
+        return collected
+
+    def visit_multi_select_list(self, node, value):
+        if value is None:
+            return None
+        collected = []
+        for child in node['children']:
+            collected.append(self.visit(child, value))
+        return collected
+
+    def visit_or_expression(self, node, value):
+        matched = self.visit(node['children'][0], value)
+        if self._is_false(matched):
+            matched = self.visit(node['children'][1], value)
+        return matched
+
+    def visit_and_expression(self, node, value):
+        matched = self.visit(node['children'][0], value)
+        if self._is_false(matched):
+            return matched
+        return self.visit(node['children'][1], value)
+
+    def visit_not_expression(self, node, value):
+        original_result = self.visit(node['children'][0], value)
+        if type(original_result) is int and original_result == 0:
+            # Special case for 0, !0 should be false, not true.
+            # 0 is not a special cased integer in jmespath.
+            return False
+        return not original_result
+
+    def visit_pipe(self, node, value):
+        result = value
+        for node in node['children']:
+            result = self.visit(node, result)
+        return result
+
+    def visit_projection(self, node, value):
+        base = self.visit(node['children'][0], value)
+        if not isinstance(base, list):
+            return None
+        collected = []
+        for element in base:
+            current = self.visit(node['children'][1], element)
+            if current is not None:
+                collected.append(current)
+        return collected
+
+    def visit_value_projection(self, node, value):
+        base = self.visit(node['children'][0], value)
+        try:
+            base = base.values()
+        except AttributeError:
+            return None
+        collected = []
+        for element in base:
+            current = self.visit(node['children'][1], element)
+            if current is not None:
+                collected.append(current)
+        return collected
+
+    def _is_false(self, value):
+        # This looks weird, but we're explicitly using equality checks
+        # because the truth/false values are different between
+        # python and jmespath.
+        return (value == '' or value == [] or value == {} or value is None or
+                value is False)
+
+    def _is_true(self, value):
+        return not self._is_false(value)
+
+
+class GraphvizVisitor(Visitor):
+    def __init__(self):
+        super(GraphvizVisitor, self).__init__()
+        self._lines = []
+        self._count = 1
+
+    def visit(self, node, *args, **kwargs):
+        self._lines.append('digraph AST {')
+        current = '%s%s' % (node['type'], self._count)
+        self._count += 1
+        self._visit(node, current)
+        self._lines.append('}')
+        return '\n'.join(self._lines)
+
+    def _visit(self, node, current):
+        self._lines.append('%s [label="%s(%s)"]' % (
+            current, node['type'], node.get('value', '')))
+        for child in node.get('children', []):
+            child_name = '%s%s' % (child['type'], self._count)
+            self._count += 1
+            self._lines.append('  %s -> %s' % (current, child_name))
+            self._visit(child, child_name)