Files
spack/lib/spack/external/ruamel/yaml/resolver.py
Todd Gamblin 63004e3de1 yaml: use ruamel.yaml instead of pyyaml
- ruamel.yaml allows round-tripping comments from/to files
- ruamel.yaml is single-source, python2/python3 compatible
2018-08-20 16:36:04 -07:00

398 lines
14 KiB
Python

# coding: utf-8
from __future__ import absolute_import
import re
try:
from .error import * # NOQA
from .nodes import * # NOQA
from .compat import string_types
except (ImportError, ValueError): # for Jython
from ruamel.yaml.error import * # NOQA
from ruamel.yaml.nodes import * # NOQA
from ruamel.yaml.compat import string_types
__all__ = ['BaseResolver', 'Resolver', 'VersionedResolver']
_DEFAULT_VERSION = (1, 2)
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._loader_version = None
self.resolver_exact_paths = []
self.resolver_prefix_paths = []
@classmethod
def add_implicit_resolver(cls, tag, regexp, first):
if 'yaml_implicit_resolvers' not 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))
@classmethod
def add_path_resolver(cls, tag, path, kind=None):
# Note: `add_path_resolver` is experimental. The API could be changed.
# `new_path` is a pattern that is matched against the path from the
# root to the node that is being considered. `node_path` elements are
# tuples `(node_check, index_check)`. `node_check` is a node class:
# `ScalarNode`, `SequenceNode`, `MappingNode` or `None`. `None`
# matches any kind of a node. `index_check` could be `None`, a boolean
# value, a string value, or a number. `None` and `False` match against
# any _value_ of sequence and mapping nodes. `True` matches against
# any _key_ of a mapping node. A string `index_check` matches against
# a mapping value that corresponds to a scalar key which content is
# equal to the `index_check` value. An integer `index_check` matches
# against a sequence value with the index equal to `index_check`.
if 'yaml_path_resolvers' not 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, string_types) \
and node_check is not None:
raise ResolverError("Invalid node checker: %s" % node_check)
if not isinstance(index_check, (string_types, 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
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, string_types):
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 is False or index_check is None) \
and current_index is None:
return
if isinstance(index_check, string_types):
if not (isinstance(current_index, ScalarNode) and
index_check == current_index.value):
return
elif isinstance(index_check, int) and not isinstance(index_check,
bool):
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
@property
def processing_version(self):
return None
class Resolver(BaseResolver):
pass
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:bool',
re.compile(u'''^(?:yes|Yes|YES|no|No|NO
|true|True|TRUE|false|False|FALSE
|on|On|ON|off|Off|OFF)$''', re.X),
list(u'yYnNtTfFoO'))
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:float',
re.compile(u'''^(?:
[-+]?(?:[0-9][0-9_]*)\\.[0-9_]*(?:[eE][-+]?[0-9]+)?
|[-+]?(?:[0-9][0-9_]*)(?:[eE][-+]?[0-9]+)
|\\.[0-9_]+(?:[eE][-+][0-9]+)?
|[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\\.[0-9_]*
|[-+]?\\.(?:inf|Inf|INF)
|\\.(?:nan|NaN|NAN))$''', re.X),
list(u'-+0123456789.'))
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:int',
re.compile(u'''^(?:[-+]?0b[0-1_]+
|[-+]?0o?[0-7_]+
|[-+]?(?:0|[1-9][0-9_]*)
|[-+]?0x[0-9a-fA-F_]+
|[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
list(u'-+0123456789'))
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:merge',
re.compile(u'^(?:<<)$'),
[u'<'])
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:null',
re.compile(u'''^(?: ~
|null|Null|NULL
| )$''', re.X),
[u'~', u'n', u'N', u''])
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:timestamp',
re.compile(u'''^(?:[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]
|[0-9][0-9][0-9][0-9] -[0-9][0-9]? -[0-9][0-9]?
(?:[Tt]|[ \\t]+)[0-9][0-9]?
:[0-9][0-9] :[0-9][0-9] (?:\\.[0-9]*)?
(?:[ \\t]*(?:Z|[-+][0-9][0-9]?(?::[0-9][0-9])?))?)$''', re.X),
list(u'0123456789'))
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:value',
re.compile(u'^(?:=)$'),
[u'='])
# The following resolver is only for documentation purposes. It cannot work
# because plain scalars cannot start with '!', '&', or '*'.
Resolver.add_implicit_resolver(
u'tag:yaml.org,2002:yaml',
re.compile(u'^(?:!|&|\\*)$'),
list(u'!&*'))
# resolvers consist of
# - a list of applicable version
# - a tag
# - a regexp
# - a list of first characters to match
implicit_resolvers = [
([(1, 2)],
u'tag:yaml.org,2002:bool',
re.compile(u'''^(?:true|True|TRUE|false|False|FALSE)$''', re.X),
list(u'tTfF')),
([(1, 1)],
u'tag:yaml.org,2002:bool',
re.compile(u'''^(?:yes|Yes|YES|no|No|NO
|true|True|TRUE|false|False|FALSE
|on|On|ON|off|Off|OFF)$''', re.X),
list(u'yYnNtTfFoO')),
([(1, 2), (1, 1)],
u'tag:yaml.org,2002:float',
re.compile(u'''^(?:
[-+]?(?:[0-9][0-9_]*)\\.[0-9_]*(?:[eE][-+]?[0-9]+)?
|[-+]?(?:[0-9][0-9_]*)(?:[eE][-+]?[0-9]+)
|\\.[0-9_]+(?:[eE][-+][0-9]+)?
|[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\\.[0-9_]*
|[-+]?\\.(?:inf|Inf|INF)
|\\.(?:nan|NaN|NAN))$''', re.X),
list(u'-+0123456789.')),
([(1, 2)],
u'tag:yaml.org,2002:int',
re.compile(u'''^(?:[-+]?0b[0-1_]+
|[-+]?0o?[0-7_]+
|[-+]?(?:0|[1-9][0-9_]*)
|[-+]?0x[0-9a-fA-F_]+)$''', re.X),
list(u'-+0123456789')),
([(1, 1)],
u'tag:yaml.org,2002:int',
re.compile(u'''^(?:[-+]?0b[0-1_]+
|[-+]?0o?[0-7_]+
|[-+]?(?:0|[1-9][0-9_]*)
|[-+]?0x[0-9a-fA-F_]+
|[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
list(u'-+0123456789')),
([(1, 2), (1, 1)],
u'tag:yaml.org,2002:merge',
re.compile(u'^(?:<<)$'),
[u'<']),
([(1, 2), (1, 1)],
u'tag:yaml.org,2002:null',
re.compile(u'''^(?: ~
|null|Null|NULL
| )$''', re.X),
[u'~', u'n', u'N', u'']),
([(1, 2), (1, 1)],
u'tag:yaml.org,2002:timestamp',
re.compile(u'''^(?:[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]
|[0-9][0-9][0-9][0-9] -[0-9][0-9]? -[0-9][0-9]?
(?:[Tt]|[ \\t]+)[0-9][0-9]?
:[0-9][0-9] :[0-9][0-9] (?:\\.[0-9]*)?
(?:[ \\t]*(?:Z|[-+][0-9][0-9]?(?::[0-9][0-9])?))?)$''', re.X),
list(u'0123456789')),
([(1, 2), (1, 1)],
u'tag:yaml.org,2002:value',
re.compile(u'^(?:=)$'),
[u'=']),
# The following resolver is only for documentation purposes. It cannot work
# because plain scalars cannot start with '!', '&', or '*'.
([(1, 2), (1, 1)],
u'tag:yaml.org,2002:yaml',
re.compile(u'^(?:!|&|\\*)$'),
list(u'!&*')),
]
class VersionedResolver(BaseResolver):
"""
contrary to the "normal" resolver, the smart resolver delays loading
the pattern matching rules. That way it can decide to load 1.1 rules
or the (default) 1.2 that no longer support octal without 0o, sexagesimals
and Yes/No/On/Off booleans.
"""
def __init__(self, version=None):
BaseResolver.__init__(self)
self._loader_version = self.get_loader_version(version)
self._version_implicit_resolver = {}
def add_version_implicit_resolver(self, version, tag, regexp, first):
if first is None:
first = [None]
impl_resolver = self._version_implicit_resolver.setdefault(version, {})
for ch in first:
impl_resolver.setdefault(ch, []).append((tag, regexp))
def get_loader_version(self, version):
if version is None or isinstance(version, tuple):
return version
if isinstance(version, list):
return tuple(version)
# assume string
return tuple(map(int, version.split(u'.')))
@property
def resolver(self):
"""
select the resolver based on the version we are parsing
"""
version = self.processing_version
if version not in self._version_implicit_resolver:
for x in implicit_resolvers:
if version in x[0]:
self.add_version_implicit_resolver(version, x[1], x[2], x[3])
return self._version_implicit_resolver[version]
def resolve(self, kind, value, implicit):
if kind is ScalarNode and implicit[0]:
if value == u'':
resolvers = self.resolver.get(u'', [])
else:
resolvers = self.resolver.get(value[0], [])
resolvers += self.resolver.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
@property
def processing_version(self):
try:
version = self.yaml_version
except AttributeError:
# dumping
version = self.use_version
if version is None:
version = self._loader_version
if version is None:
version = _DEFAULT_VERSION
return version