1. Kirill Simonov
  2. pyyaml

Source

pyyaml / lib / yaml / resolver.py

Kirill Simonov e51f297 










Kirill Simonov 988f014 
Kirill Simonov e51f297 














Kirill Simonov cec54e5 

Kirill Simonov e51f297 























Kirill Simonov 136cb5e 
Kirill Simonov e51f297 












Kirill Simonov 136cb5e 
Kirill Simonov e51f297 







Kirill Simonov f14733c 

Kirill Simonov e51f297 




















Kirill Simonov f14733c 

Kirill Simonov e51f297 



































Kirill Simonov f14733c 





Kirill Simonov e51f297 











Kirill Simonov 5a4688f 
Kirill Simonov e51f297 





















































__all__ = ['BaseResolver', 'Resolver']

from error import *
from nodes import *

import re

class ResolverError(YAMLError):
    pass

class BaseResolver(object):

    DEFAULT_SCALAR_TAG = u'tag:yaml.org,2002:str'
    DEFAULT_SEQUENCE_TAG = u'tag:yaml.org,2002:seq'
    DEFAULT_MAPPING_TAG = u'tag:yaml.org,2002:map'

    yaml_implicit_resolvers = {}
    yaml_path_resolvers = {}

    def __init__(self):
        self.resolver_exact_paths = []
        self.resolver_prefix_paths = []

    def add_implicit_resolver(cls, tag, regexp, first):
        if not 'yaml_implicit_resolvers' in cls.__dict__:
            cls.yaml_implicit_resolvers = cls.yaml_implicit_resolvers.copy()
        if first is None:
            first = [None]
        for ch in first:
            cls.yaml_implicit_resolvers.setdefault(ch, []).append((tag, regexp))
    add_implicit_resolver = classmethod(add_implicit_resolver)

    def add_path_resolver(cls, tag, path, kind=None):
        if not 'yaml_path_resolvers' in cls.__dict__:
            cls.yaml_path_resolvers = cls.yaml_path_resolvers.copy()
        new_path = []
        for element in path:
            if isinstance(element, (list, tuple)):
                if len(element) == 2:
                    node_check, index_check = element
                elif len(element) == 1:
                    node_check = element[0]
                    index_check = True
                else:
                    raise ResolverError("Invalid path element: %s" % element)
            else:
                node_check = None
                index_check = element
            if node_check is str:
                node_check = ScalarNode
            elif node_check is list:
                node_check = SequenceNode
            elif node_check is dict:
                node_check = MappingNode
            elif node_check not in [ScalarNode, SequenceNode, MappingNode]  \
                    and not isinstance(node_check, basestring)  \
                    and node_check is not None:
                raise ResolverError("Invalid node checker: %s" % node_check)
            if not isinstance(index_check, (basestring, int))   \
                    and index_check is not None:
                raise ResolverError("Invalid index checker: %s" % index_check)
            new_path.append((node_check, index_check))
        if kind is str:
            kind = ScalarNode
        elif kind is list:
            kind = SequenceNode
        elif kind is dict:
            kind = MappingNode
        elif kind not in [ScalarNode, SequenceNode, MappingNode]    \
                and kind is not None:
            raise ResolverError("Invalid node kind: %s" % kind)
        cls.yaml_path_resolvers[tuple(new_path), kind] = tag
    add_path_resolver = classmethod(add_path_resolver)

    def descend_resolver(self, current_node, current_index):
        if not self.yaml_path_resolvers:
            return
        exact_paths = {}
        prefix_paths = []
        if current_node:
            depth = len(self.resolver_prefix_paths)
            for path, kind in self.resolver_prefix_paths[-1]:
                if self.check_resolver_prefix(depth, path, kind,
                        current_node, current_index):
                    if len(path) > depth:
                        prefix_paths.append((path, kind))
                    else:
                        exact_paths[kind] = self.yaml_path_resolvers[path, kind]
        else:
            for path, kind in self.yaml_path_resolvers:
                if not path:
                    exact_paths[kind] = self.yaml_path_resolvers[path, kind]
                else:
                    prefix_paths.append((path, kind))
        self.resolver_exact_paths.append(exact_paths)
        self.resolver_prefix_paths.append(prefix_paths)

    def ascend_resolver(self):
        if not self.yaml_path_resolvers:
            return
        self.resolver_exact_paths.pop()
        self.resolver_prefix_paths.pop()

    def check_resolver_prefix(self, depth, path, kind,
            current_node, current_index):
        node_check, index_check = path[depth-1]
        if isinstance(node_check, basestring):
            if current_node.tag != node_check:
                return
        elif node_check is not None:
            if not isinstance(current_node, node_check):
                return
        if index_check is True and current_index is not None:
            return
        if index_check in [False, None] and current_index is None:
            return
        if isinstance(index_check, basestring):
            if not (isinstance(current_index, ScalarNode)
                    and index_check == current_index.value):
                return
        elif isinstance(index_check, int):
            if index_check != current_index:
                return
        return True

    def resolve(self, kind, value, implicit):
        if kind is ScalarNode and implicit[0]:
            if value == u'':
                resolvers = self.yaml_implicit_resolvers.get(u'', [])
            else:
                resolvers = self.yaml_implicit_resolvers.get(value[0], [])
            resolvers += self.yaml_implicit_resolvers.get(None, [])
            for tag, regexp in resolvers:
                if regexp.match(value):
                    return tag
            implicit = implicit[1]
        if self.yaml_path_resolvers:
            exact_paths = self.resolver_exact_paths[-1]
            if kind in exact_paths:
                return exact_paths[kind]
            if None in exact_paths:
                return exact_paths[None]
        if kind is ScalarNode:
            return self.DEFAULT_SCALAR_TAG
        elif kind is SequenceNode:
            return self.DEFAULT_SEQUENCE_TAG
        elif kind is MappingNode:
            return self.DEFAULT_MAPPING_TAG

class Resolver(BaseResolver):
    pass

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:bool',
        re.compile(ur'''^(?:yes|Yes|YES|no|No|NO
                    |true|True|TRUE|false|False|FALSE
                    |on|On|ON|off|Off|OFF)$''', re.X),
        list(u'yYnNtTfFoO'))

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:float',
        re.compile(ur'''^(?:[-+]?(?:[0-9][0-9_]*)?\.[0-9_]*(?:[eE][-+][0-9]+)?
                    |[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\.[0-9_]*
                    |[-+]?\.(?:inf|Inf|INF)
                    |\.(?:nan|NaN|NAN))$''', re.X),
        list(u'-+0123456789.'))

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:int',
        re.compile(ur'''^(?:[-+]?0b[0-1_]+
                    |[-+]?0[0-7_]+
                    |[-+]?(?:0|[1-9][0-9_]*)
                    |[-+]?0x[0-9a-fA-F_]+
                    |[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
        list(u'-+0123456789'))

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:merge',
        re.compile(ur'^(?:<<)$'),
        ['<'])

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:null',
        re.compile(ur'''^(?: ~
                    |null|Null|NULL
                    | )$''', re.X),
        [u'~', u'n', u'N', u''])

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:timestamp',
        re.compile(ur'''^(?:[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]
                    |[0-9][0-9][0-9][0-9] -[0-9][0-9]? -[0-9][0-9]?
                     (?:[Tt]|[ \t]+)[0-9][0-9]?
                     :[0-9][0-9] :[0-9][0-9] (?:\.[0-9]*)?
                     (?:[ \t]*(?:Z|[-+][0-9][0-9]?(?::[0-9][0-9])?))?)$''', re.X),
        list(u'0123456789'))

Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:value',
        re.compile(ur'^(?:=)$'),
        ['='])

# The following resolver is only for documentation purposes. It cannot work
# because plain scalars cannot start with '!', '&', or '*'.
Resolver.add_implicit_resolver(
        u'tag:yaml.org,2002:yaml',
        re.compile(ur'^(?:!|&|\*)$'),
        list(u'!&*'))