diff --git a/.appveyor.yml b/.appveyor.yml
deleted file mode 100644
index 65358bdb..00000000
--- a/.appveyor.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-# TODO: update this from inside the build to use branch current version
-version: '{build}'
-
-image:
-- Visual Studio 2015
-
-#cache:
-#- 'C:\Python38\'
-#- 'C:\Python38-x64'
-
-environment:
-  libyaml_repo_url: https://github.com/yaml/libyaml.git
-  libyaml_refspec: 0.2.5
-  PYYAML_TEST_GROUP: all
-
-#  matrix:
-#    - PYTHON_VER: Python36
-#    - PYTHON_VER: Python36-x64
-#    - PYTHON_VER: Python37
-#    - PYTHON_VER: Python37-x64
-#    - PYTHON_VER: Python38
-#    - PYTHON_VER: Python38-x64
-#    - PYTHON_VER: Python39
-#    - PYTHON_VER: Python39-x64
-
-#init:
-#- ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
-
-build_script:
-- ps: packaging\build\appveyor.ps1
-
-#on_finish:
-#- ps: $blockRdp = $true; iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 777839cd..bb1b550b 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -12,59 +12,59 @@ env:
   LIBYAML_REF: 0.2.5
 
 jobs:
-  python_sdist:
-    name: PyYAML sdist
-    runs-on: ubuntu-latest
-    steps:
-    - name: Checkout pyyaml
-      uses: actions/checkout@v2
-
-    - name: Install a python
-      uses: actions/setup-python@v2
-      with:
-        python-version: 3.x
-
-    - name: Install build deps
-      run: |
-        python -V
-        python -m pip install build
-
-    - name: Build sdist
-      run: |
-        # We DO want to force Cythoning, at least until 6.0.
-        export PYYAML_FORCE_CYTHON=1
-        # We don't actually want to build the lib.
-        export PYYAML_FORCE_LIBYAML=0
-
-        python -m build .
-
-        # Ensure exactly one artifact was produced.
-        [[ $(shopt -s nullglob; ls dist/*.tar.gz | wc -w) == 1 ]] || {
-          echo "Unexpected content in dist dir: '$(ls dist/*.tar.gz)'."
-          exit 1
-        }
-
-    - name: Test sdist
-      run: |
-        # Install some libyaml headers.
-        # TODO Should we smoke test the sdist against the libyaml we built?
-        sudo apt update
-        sudo apt install libyaml-dev -y
-
-        # Ensure Cython is not present so we use only what's in the sdist.
-        python -m pip uninstall Cython -y || true
-
-        # Pass no extra args.
-        # We should auto-install with libyaml since it's present.
-        python -m pip install dist/*.tar.gz -v
-
-        python packaging/build/smoketest.py
-
-    - name: Upload sdist artifact
-      uses: actions/upload-artifact@v2
-      with:
-        name: dist
-        path: dist/*.tar.gz
+#  python_sdist:
+#    name: PyYAML sdist
+#    runs-on: ubuntu-latest
+#    steps:
+#    - name: Checkout pyyaml
+#      uses: actions/checkout@v2
+#
+#    - name: Install a python
+#      uses: actions/setup-python@v2
+#      with:
+#        python-version: 3.x
+#
+#    - name: Install build deps
+#      run: |
+#        python -V
+#        python -m pip install build
+#
+#    - name: Build sdist
+#      run: |
+#        # We DO want to force Cythoning, at least until 6.0.
+#        export PYYAML_FORCE_CYTHON=1
+#        # We don't actually want to build the lib.
+#        export PYYAML_FORCE_LIBYAML=0
+#
+#        python -m build .
+#
+#        # Ensure exactly one artifact was produced.
+#        [[ $(shopt -s nullglob; ls dist/*.tar.gz | wc -w) == 1 ]] || {
+#          echo "Unexpected content in dist dir: '$(ls dist/*.tar.gz)'."
+#          exit 1
+#        }
+#
+#    - name: Test sdist
+#      run: |
+#        # Install some libyaml headers.
+#        # TODO Should we smoke test the sdist against the libyaml we built?
+#        sudo apt update
+#        sudo apt install libyaml-dev -y
+#
+#        # Ensure Cython is not present so we use only what's in the sdist.
+#        python -m pip uninstall Cython -y || true
+#
+#        # Pass no extra args.
+#        # We should auto-install with libyaml since it's present.
+#        python -m pip install dist/*.tar.gz -v
+#
+#        python packaging/build/smoketest.py
+#
+#    - name: Upload sdist artifact
+#      uses: actions/upload-artifact@v2
+#      with:
+#        name: dist
+#        path: dist/*.tar.gz
 
 
   linux_libyaml:
@@ -74,8 +74,8 @@ jobs:
       matrix:
         cfg:
         - { platform: manylinux1, arch: x86_64 }
-        - { platform: manylinux2014, arch: aarch64 }
-        - { platform: manylinux2014, arch: s390x }
+#        - { platform: manylinux2014, arch: aarch64 }
+#        - { platform: manylinux2014, arch: s390x }
     env:
       DOCKER_IMAGE: quay.io/pypa/${{matrix.cfg.platform}}_${{matrix.cfg.arch}}
     steps:
@@ -86,9 +86,9 @@ jobs:
         path: libyaml
         key: libyamlX_${{matrix.cfg.platform}}_${{matrix.cfg.arch}}_${{env.LIBYAML_REF}}
 
-    - name: configure docker foreign arch support
-      uses: docker/setup-qemu-action@v1
-      if: matrix.cfg.arch != 'x86_64' && steps.cached_libyaml.outputs.cache-hit != 'true'
+#    - name: configure docker foreign arch support
+#      uses: docker/setup-qemu-action@v1
+#      if: matrix.cfg.arch != 'x86_64' && steps.cached_libyaml.outputs.cache-hit != 'true'
 
     - name: Checkout pyyaml
       uses: actions/checkout@v2
@@ -118,18 +118,18 @@ jobs:
     strategy:
       matrix:
         cfg:
-        - { platform: manylinux1, arch: x86_64, python_tag: cp36-cp36m }
-        - { platform: manylinux1, arch: x86_64, python_tag: cp37-cp37m }
-        - { platform: manylinux1, arch: x86_64, python_tag: cp38-cp38 }
+#        - { platform: manylinux1, arch: x86_64, python_tag: cp36-cp36m }
+#        - { platform: manylinux1, arch: x86_64, python_tag: cp37-cp37m }
+#        - { platform: manylinux1, arch: x86_64, python_tag: cp38-cp38 }
         - { platform: manylinux1, arch: x86_64, python_tag: cp39-cp39 }
-        - { platform: manylinux2014, arch: aarch64, python_tag: cp36-cp36m }
-        - { platform: manylinux2014, arch: aarch64, python_tag: cp37-cp37m }
-        - { platform: manylinux2014, arch: aarch64, python_tag: cp38-cp38 }
-        - { platform: manylinux2014, arch: aarch64, python_tag: cp39-cp39 }
-        - { platform: manylinux2014, arch: s390x, python_tag: cp36-cp36m }
-        - { platform: manylinux2014, arch: s390x, python_tag: cp37-cp37m }
-        - { platform: manylinux2014, arch: s390x, python_tag: cp38-cp38 }
-        - { platform: manylinux2014, arch: s390x, python_tag: cp39-cp39 }
+#        - { platform: manylinux2014, arch: aarch64, python_tag: cp36-cp36m }
+#        - { platform: manylinux2014, arch: aarch64, python_tag: cp37-cp37m }
+#        - { platform: manylinux2014, arch: aarch64, python_tag: cp38-cp38 }
+#        - { platform: manylinux2014, arch: aarch64, python_tag: cp39-cp39 }
+#        - { platform: manylinux2014, arch: s390x, python_tag: cp36-cp36m }
+#        - { platform: manylinux2014, arch: s390x, python_tag: cp37-cp37m }
+#        - { platform: manylinux2014, arch: s390x, python_tag: cp38-cp38 }
+#        - { platform: manylinux2014, arch: s390x, python_tag: cp39-cp39 }
     env:
       AW_PLAT: ${{matrix.cfg.platform}}_${{matrix.cfg.arch}}
       DOCKER_IMAGE: quay.io/pypa/${{matrix.cfg.platform}}_${{matrix.cfg.arch}}
@@ -176,78 +176,78 @@ jobs:
         name: dist
         path: dist/*.whl
 
-  macos_libyaml:
-    name: libyaml ${{matrix.arch}} ${{matrix.platform}}
-    runs-on: ${{matrix.platform}}
-    strategy:
-      matrix:
-        platform:
-        - macos-10.15
-        arch:
-        - x86_64
-    steps:
-    - name: Check cached libyaml state
-      id: cached_libyaml
-      uses: actions/cache@v2
-      with:
-        path: libyaml
-        key: libyaml_${{matrix.platform}}_${{matrix.arch}}_${{env.LIBYAML_REF}}
-
-    - name: Checkout pyyaml
-      uses: actions/checkout@v2
-      if: steps.cached_libyaml.outputs.cache-hit != 'true'
-
-    - name: Build libyaml
-      env:
-        MACOSX_DEPLOYMENT_TARGET: '10.9'
-      run: |
-        brew install automake coreutils
-        bash ./packaging/build/libyaml.sh
-      if: steps.cached_libyaml.outputs.cache-hit != 'true'
-
-  macos_pyyaml:
-    needs: macos_libyaml
-    name: pyyaml ${{matrix.arch}} ${{matrix.platform}} ${{matrix.python_tag}}
-    runs-on: ${{matrix.platform}}
-    strategy:
-      matrix:
-        platform:
-        - macos-10.15
-        arch:
-        - x86_64
-        python_tag:
-        - cp36*
-        - cp37*
-        - cp38*
-        - cp39*
-    steps:
-    - name: Checkout pyyaml
-      uses: actions/checkout@v2
-
-    - name: Get cached libyaml state
-      id: cached_libyaml
-      uses: actions/cache@v2
-      with:
-        path: libyaml
-        key: libyaml_${{matrix.platform}}_${{matrix.arch}}_${{env.LIBYAML_REF}}
-
-    - name: Ensure libyaml fetched
-      run: exit 1
-      if: steps.cached_libyaml.outputs.cache-hit != 'true'
-
-    - name: Install a python
-      uses: actions/setup-python@v2
-      with:
-        python-version: 3.x
-
-    - name: Build/Test/Package
-      env:
-        CIBW_BUILD: ${{matrix.python_tag}}
-        CIBW_BUILD_VERBOSITY: 1
-      run: bash ./packaging/build/macos.sh
-
-    - uses: actions/upload-artifact@v2
-      with:
-        name: dist
-        path: dist/*.whl
+#  macos_libyaml:
+#    name: libyaml ${{matrix.arch}} ${{matrix.platform}}
+#    runs-on: ${{matrix.platform}}
+#    strategy:
+#      matrix:
+#        platform:
+#        - macos-10.15
+#        arch:
+#        - x86_64
+#    steps:
+#    - name: Check cached libyaml state
+#      id: cached_libyaml
+#      uses: actions/cache@v2
+#      with:
+#        path: libyaml
+#        key: libyaml_${{matrix.platform}}_${{matrix.arch}}_${{env.LIBYAML_REF}}
+#
+#    - name: Checkout pyyaml
+#      uses: actions/checkout@v2
+#      if: steps.cached_libyaml.outputs.cache-hit != 'true'
+#
+#    - name: Build libyaml
+#      env:
+#        MACOSX_DEPLOYMENT_TARGET: '10.9'
+#      run: |
+#        brew install automake coreutils
+#        bash ./packaging/build/libyaml.sh
+#      if: steps.cached_libyaml.outputs.cache-hit != 'true'
+#
+#  macos_pyyaml:
+#    needs: macos_libyaml
+#    name: pyyaml ${{matrix.arch}} ${{matrix.platform}} ${{matrix.python_tag}}
+#    runs-on: ${{matrix.platform}}
+#    strategy:
+#      matrix:
+#        platform:
+#        - macos-10.15
+#        arch:
+#        - x86_64
+#        python_tag:
+#        - cp36*
+#        - cp37*
+#        - cp38*
+#        - cp39*
+#    steps:
+#    - name: Checkout pyyaml
+#      uses: actions/checkout@v2
+#
+#    - name: Get cached libyaml state
+#      id: cached_libyaml
+#      uses: actions/cache@v2
+#      with:
+#        path: libyaml
+#        key: libyaml_${{matrix.platform}}_${{matrix.arch}}_${{env.LIBYAML_REF}}
+#
+#    - name: Ensure libyaml fetched
+#      run: exit 1
+#      if: steps.cached_libyaml.outputs.cache-hit != 'true'
+#
+#    - name: Install a python
+#      uses: actions/setup-python@v2
+#      with:
+#        python-version: 3.x
+#
+#    - name: Build/Test/Package
+#      env:
+#        CIBW_BUILD: ${{matrix.python_tag}}
+#        CIBW_BUILD_VERBOSITY: 1
+#      run: bash ./packaging/build/macos.sh
+#
+#    - uses: actions/upload-artifact@v2
+#      with:
+#        name: dist
+#        path: dist/*.whl
 ...
diff --git a/lib/yaml/__init__.py b/lib/yaml/__init__.py
index 86d07b55..856caf52 100644
--- a/lib/yaml/__init__.py
+++ b/lib/yaml/__init__.py
@@ -202,6 +202,7 @@ def emit(events, stream=None, Dumper=Dumper,
     if stream is None:
         stream = io.StringIO()
         getvalue = stream.getvalue
+    # FIXME: redefine these defaults with sentinels to allow preservation of wrapped config defaults
     dumper = Dumper(stream, canonical=canonical, indent=indent, width=width,
             allow_unicode=allow_unicode, line_break=line_break)
     try:
@@ -228,6 +229,7 @@ def serialize_all(nodes, stream=None, Dumper=Dumper,
         else:
             stream = io.BytesIO()
         getvalue = stream.getvalue
+    # FIXME: redefine these defaults with sentinels to allow preservation of wrapped config defaults
     dumper = Dumper(stream, canonical=canonical, indent=indent, width=width,
             allow_unicode=allow_unicode, line_break=line_break,
             encoding=encoding, version=version, tags=tags,
@@ -250,28 +252,35 @@ def serialize(node, stream=None, Dumper=Dumper, **kwds):
     return serialize_all([node], stream, Dumper=Dumper, **kwds)
 
 def dump_all(documents, stream=None, Dumper=Dumper,
-        default_style=None, default_flow_style=False,
-        canonical=None, indent=None, width=None,
-        allow_unicode=None, line_break=None,
-        encoding=None, explicit_start=None, explicit_end=None,
-        version=None, tags=None, sort_keys=True):
+        default_style=..., default_flow_style=...,
+        canonical=..., indent=..., width=...,
+        allow_unicode=..., line_break=...,
+        encoding=..., explicit_start=..., explicit_end=...,
+        version=..., tags=..., sort_keys=..., **kwargs):
     """
     Serialize a sequence of Python objects into a YAML stream.
     If stream is None, return the produced string instead.
     """
     getvalue = None
     if stream is None:
-        if encoding is None:
+        if encoding is None or encoding is ...:
             stream = io.StringIO()
         else:
             stream = io.BytesIO()
         getvalue = stream.getvalue
-    dumper = Dumper(stream, default_style=default_style,
-            default_flow_style=default_flow_style,
-            canonical=canonical, indent=indent, width=width,
-            allow_unicode=allow_unicode, line_break=line_break,
-            encoding=encoding, version=version, tags=tags,
-            explicit_start=explicit_start, explicit_end=explicit_end, sort_keys=sort_keys)
+
+    # preserve wrapped config defaults for values where we didn't get a default
+    # FIXME: share this code with the one in config mixin
+    dumper_init_kwargs = dict(
+        default_style=default_style,
+        default_flow_style=default_flow_style,
+        canonical=canonical, indent=indent, width=width,
+        allow_unicode=allow_unicode, line_break=line_break,
+        encoding=encoding, version=version, tags=tags,
+        explicit_start=explicit_start, explicit_end=explicit_end, sort_keys=sort_keys, **kwargs)
+
+    dumper_init_kwargs = {k: v for k, v in dumper_init_kwargs.items() if v is not ...}
+    dumper = Dumper(stream, **dumper_init_kwargs)
     try:
         dumper.open()
         for data in documents:
@@ -381,7 +390,17 @@ def add_multi_representer(data_type, multi_representer, Dumper=Dumper):
     """
     Dumper.add_multi_representer(data_type, multi_representer)
 
+def experimental_12_Core_loader():
+    return loader._12_CoreLoader
+def experimental_12_JSON_loader():
+    return loader._12_JSONLoader
+
+def experimental_12_Core_dumper():
+    return dumper._12_CoreDumper
+def experimental_12_JSON_dumper():
+    return dumper._12_JSONDumper
 class YAMLObjectMetaclass(type):
+
     """
     The metaclass for YAMLObject.
     """
diff --git a/lib/yaml/config.py b/lib/yaml/config.py
new file mode 100644
index 00000000..df8aeee8
--- /dev/null
+++ b/lib/yaml/config.py
@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import typing as t
+
+from functools import partialmethod
+from .tagset import TagSet
+
+T = t.TypeVar('T')
+
+
+class LoaderConfigMixin:
+    @classmethod
+    # FIXME: fix tagset type to use DataClasses, at least externally?
+    def config(cls: type[T], type_name: str | None = None, tagset: TagSet | ... = ..., **kwargs) -> type[T]:
+        if not type_name:
+            # FIXME: hash the inputs for a dynamic type name and cache it?
+            type_name = f'abcd_from_{cls.__name__}'
+
+        new_type = t.cast(cls, type(type_name, (cls, ), {}))
+
+        # FIXME: add support for arbitrary kwargs passthru ala dumper?
+
+        if tagset is not ...:
+            # FIXME: provide a base class hook/method for this reset
+            new_type.yaml_implicit_resolvers = {}
+            new_type.init_resolvers(tagset.resolvers)
+            new_type.yaml_constructors = {}
+            new_type.init_constructors(tagset.constructors)
+
+        return new_type
+
+
+class DumperConfigMixin:
+    @classmethod
+    def config(cls: type[T], type_name: str | None = None,
+               tagset: TagSet | ... = ...,
+               # FIXME: make some of the more obscure style things "nicer" (eg enums?) or just pass through existing values?
+               default_style: str | ... = ..., default_flow_style: bool | ... = ...,
+               # FIXME: properly type-annotate the rest of these
+               canonical=..., indent=..., width=...,
+               allow_unicode=..., line_break=...,
+               encoding=..., explicit_start=..., explicit_end=...,
+               version=..., tags=..., sort_keys=...,
+               **kwargs) -> type[T]:
+
+        if not type_name:
+            # FIXME: hash the inputs for a dynamic type name and cache it?
+            type_name = f'abcd_from_{cls.__name__}'
+
+        # preserve wrapped config defaults for values where we didn't get a default
+        # FIXME: share this code with the one in __init__.dump_all (and implement on others)
+        dumper_init_kwargs = dict(
+            default_style=default_style,
+            default_flow_style=default_flow_style,
+            canonical=canonical, indent=indent, width=width,
+            allow_unicode=allow_unicode, line_break=line_break,
+            encoding=encoding, version=version, tags=tags,
+            explicit_start=explicit_start, explicit_end=explicit_end, sort_keys=sort_keys, **kwargs)
+
+        dumper_init_kwargs = {k: v for k, v in dumper_init_kwargs.items() if v is not ...}
+
+        patched_init = partialmethod(cls.__init__,
+                                     **dumper_init_kwargs)
+
+        new_type = t.cast(cls, type(type_name, (cls, ), {'__init__': patched_init}))
+
+        # FIXME: support all the dynamic dispatch types (multi*, etc)
+        if tagset is not ...:
+            # FIXME: provide a base class hook/method for this reset
+            new_type.yaml_implicit_resolvers = {}
+            new_type.init_resolvers(tagset.resolvers)
+            new_type.yaml_representers = {}
+            new_type.init_representers(tagset.representers)
+
+        return new_type
diff --git a/lib/yaml/constructor.py b/lib/yaml/constructor.py
index 619acd30..73f421d4 100644
--- a/lib/yaml/constructor.py
+++ b/lib/yaml/constructor.py
@@ -5,19 +5,26 @@
     'FullConstructor',
     'UnsafeConstructor',
     'Constructor',
-    'ConstructorError'
+    'ConstructorError',
 ]
 
 from .error import *
 from .nodes import *
 
 import collections.abc, datetime, base64, binascii, re, sys, types
+import typing as t
 
 class ConstructorError(MarkedYAMLError):
     pass
 
 class BaseConstructor:
 
+    inf_value = 1e300
+    while inf_value != inf_value*inf_value:
+        inf_value *= inf_value
+    nan_value = -inf_value/inf_value   # Trying to make a quiet NaN (like C99).
+
+
     yaml_constructors = {}
     yaml_multi_constructors = {}
 
@@ -156,67 +163,6 @@ def construct_pairs(self, node, deep=False):
             pairs.append((key, value))
         return pairs
 
-    @classmethod
-    def add_constructor(cls, tag, constructor):
-        if not 'yaml_constructors' in cls.__dict__:
-            cls.yaml_constructors = cls.yaml_constructors.copy()
-        cls.yaml_constructors[tag] = constructor
-
-    @classmethod
-    def add_multi_constructor(cls, tag_prefix, multi_constructor):
-        if not 'yaml_multi_constructors' in cls.__dict__:
-            cls.yaml_multi_constructors = cls.yaml_multi_constructors.copy()
-        cls.yaml_multi_constructors[tag_prefix] = multi_constructor
-
-class SafeConstructor(BaseConstructor):
-
-    def construct_scalar(self, node):
-        if isinstance(node, MappingNode):
-            for key_node, value_node in node.value:
-                if key_node.tag == 'tag:yaml.org,2002:value':
-                    return self.construct_scalar(value_node)
-        return super().construct_scalar(node)
-
-    def flatten_mapping(self, node):
-        merge = []
-        index = 0
-        while index < len(node.value):
-            key_node, value_node = node.value[index]
-            if key_node.tag == 'tag:yaml.org,2002:merge':
-                del node.value[index]
-                if isinstance(value_node, MappingNode):
-                    self.flatten_mapping(value_node)
-                    merge.extend(value_node.value)
-                elif isinstance(value_node, SequenceNode):
-                    submerge = []
-                    for subnode in value_node.value:
-                        if not isinstance(subnode, MappingNode):
-                            raise ConstructorError("while constructing a mapping",
-                                    node.start_mark,
-                                    "expected a mapping for merging, but found %s"
-                                    % subnode.id, subnode.start_mark)
-                        self.flatten_mapping(subnode)
-                        submerge.append(subnode.value)
-                    submerge.reverse()
-                    for value in submerge:
-                        merge.extend(value)
-                else:
-                    raise ConstructorError("while constructing a mapping", node.start_mark,
-                            "expected a mapping or list of mappings for merging, but found %s"
-                            % value_node.id, value_node.start_mark)
-            elif key_node.tag == 'tag:yaml.org,2002:value':
-                key_node.tag = 'tag:yaml.org,2002:str'
-                index += 1
-            else:
-                index += 1
-        if merge:
-            node.value = merge + node.value
-
-    def construct_mapping(self, node, deep=False):
-        if isinstance(node, MappingNode):
-            self.flatten_mapping(node)
-        return super().construct_mapping(node, deep=deep)
-
     def construct_yaml_null(self, node):
         self.construct_scalar(node)
         return None
@@ -234,42 +180,45 @@ def construct_yaml_bool(self, node):
         value = self.construct_scalar(node)
         return self.bool_values[value.lower()]
 
-    def construct_yaml_int(self, node):
+    def construct_yaml_str(self, node):
+        return self.construct_scalar(node)
+
+    def construct_yaml_seq(self, node):
+        data = []
+        yield data
+        data.extend(self.construct_sequence(node))
+
+    def construct_yaml_map(self, node):
+        data = {}
+        yield data
+        value = self.construct_mapping(node)
+        data.update(value)
+
+    def construct_undefined(self, node):
+        raise ConstructorError(None, None,
+                "could not determine a constructor for the tag %r" % node.tag,
+                node.start_mark)
+
+    def construct_yaml_int_core(self, node):
         value = self.construct_scalar(node)
-        value = value.replace('_', '')
         sign = +1
         if value[0] == '-':
             sign = -1
         if value[0] in '+-':
             value = value[1:]
+
         if value == '0':
             return 0
-        elif value.startswith('0b'):
-            return sign*int(value[2:], 2)
+        elif value.startswith('0o'):
+            return sign*int(value[2:], 8)
         elif value.startswith('0x'):
             return sign*int(value[2:], 16)
-        elif value[0] == '0':
-            return sign*int(value, 8)
-        elif ':' in value:
-            digits = [int(part) for part in value.split(':')]
-            digits.reverse()
-            base = 1
-            value = 0
-            for digit in digits:
-                value += digit*base
-                base *= 60
-            return sign*value
         else:
             return sign*int(value)
 
-    inf_value = 1e300
-    while inf_value != inf_value*inf_value:
-        inf_value *= inf_value
-    nan_value = -inf_value/inf_value   # Trying to make a quiet NaN (like C99).
-
-    def construct_yaml_float(self, node):
+    def construct_yaml_float_core(self, node):
         value = self.construct_scalar(node)
-        value = value.replace('_', '').lower()
+        value = value.lower()
         sign = +1
         if value[0] == '-':
             sign = -1
@@ -279,18 +228,56 @@ def construct_yaml_float(self, node):
             return sign*self.inf_value
         elif value == '.nan':
             return self.nan_value
-        elif ':' in value:
-            digits = [float(part) for part in value.split(':')]
-            digits.reverse()
-            base = 1
-            value = 0.0
-            for digit in digits:
-                value += digit*base
-                base *= 60
-            return sign*value
         else:
             return sign*float(value)
 
+    def construct_yaml_int_json(self, node):
+        value = self.construct_scalar(node)
+        sign = +1
+        if value[0] == '-':
+            sign = -1
+        if value[0] in '+-':
+            value = value[1:]
+
+        if value == '0':
+            return 0
+        else:
+            return sign*int(value)
+
+    def construct_yaml_float_json(self, node):
+        value = self.construct_scalar(node)
+        value = value.lower()
+        sign = +1
+        if value[0] == '-':
+            sign = -1
+        if value[0] in '+-':
+            value = value[1:]
+        return sign*float(value)
+
+    @classmethod
+    def add_constructor(cls, tag, constructor):
+        if not 'yaml_constructors' in cls.__dict__:
+            cls.yaml_constructors = cls.yaml_constructors.copy()
+        cls.yaml_constructors[tag] = constructor
+
+    @classmethod
+    def add_multi_constructor(cls, tag_prefix, multi_constructor):
+        if not 'yaml_multi_constructors' in cls.__dict__:
+            cls.yaml_multi_constructors = cls.yaml_multi_constructors.copy()
+        cls.yaml_multi_constructors[tag_prefix] = multi_constructor
+
+
+    @classmethod
+    def init_constructors(cls, tagset: dict[str, t.Callable]):
+        for type_name, constructor in tagset.items():
+            # FIXME: encode full tag names in TagSets to avoid this logic and make user-definable types easier
+            tag_name = f'tag:yaml.org,2002:{type_name}' if type_name else None
+            cls.add_constructor(tag_name, constructor)
+
+
+# SafeConstructor implements YAML 1.1
+class SafeConstructor(BaseConstructor):
+
     def construct_yaml_binary(self, node):
         try:
             value = self.construct_scalar(node).encode('ascii')
@@ -399,19 +386,104 @@ def construct_yaml_set(self, node):
         value = self.construct_mapping(node)
         data.update(value)
 
-    def construct_yaml_str(self, node):
-        return self.construct_scalar(node)
+    def construct_scalar(self, node):
+        if isinstance(node, MappingNode):
+            for key_node, value_node in node.value:
+                if key_node.tag == 'tag:yaml.org,2002:value':
+                    return self.construct_scalar(value_node)
+        return super().construct_scalar(node)
 
-    def construct_yaml_seq(self, node):
-        data = []
-        yield data
-        data.extend(self.construct_sequence(node))
+    def flatten_mapping(self, node):
+        merge = []
+        index = 0
+        while index < len(node.value):
+            key_node, value_node = node.value[index]
+            if key_node.tag == 'tag:yaml.org,2002:merge':
+                del node.value[index]
+                if isinstance(value_node, MappingNode):
+                    self.flatten_mapping(value_node)
+                    merge.extend(value_node.value)
+                elif isinstance(value_node, SequenceNode):
+                    submerge = []
+                    for subnode in value_node.value:
+                        if not isinstance(subnode, MappingNode):
+                            raise ConstructorError("while constructing a mapping",
+                                    node.start_mark,
+                                    "expected a mapping for merging, but found %s"
+                                    % subnode.id, subnode.start_mark)
+                        self.flatten_mapping(subnode)
+                        submerge.append(subnode.value)
+                    submerge.reverse()
+                    for value in submerge:
+                        merge.extend(value)
+                else:
+                    raise ConstructorError("while constructing a mapping", node.start_mark,
+                            "expected a mapping or list of mappings for merging, but found %s"
+                            % value_node.id, value_node.start_mark)
+            elif key_node.tag == 'tag:yaml.org,2002:value':
+                key_node.tag = 'tag:yaml.org,2002:str'
+                index += 1
+            else:
+                index += 1
+        if merge:
+            node.value = merge + node.value
 
-    def construct_yaml_map(self, node):
-        data = {}
-        yield data
-        value = self.construct_mapping(node)
-        data.update(value)
+    def construct_yaml_int(self, node):
+        value = self.construct_scalar(node)
+        value = value.replace('_', '')
+        sign = +1
+        if value[0] == '-':
+            sign = -1
+        if value[0] in '+-':
+            value = value[1:]
+        if value == '0':
+            return 0
+        elif value.startswith('0b'):
+            return sign*int(value[2:], 2)
+        elif value.startswith('0x'):
+            return sign*int(value[2:], 16)
+        elif value[0] == '0':
+            return sign*int(value, 8)
+        elif ':' in value:
+            digits = [int(part) for part in value.split(':')]
+            digits.reverse()
+            base = 1
+            value = 0
+            for digit in digits:
+                value += digit*base
+                base *= 60
+            return sign*value
+        else:
+            return sign*int(value)
+
+    def construct_yaml_float(self, node):
+        value = self.construct_scalar(node)
+        value = value.replace('_', '').lower()
+        sign = +1
+        if value[0] == '-':
+            sign = -1
+        if value[0] in '+-':
+            value = value[1:]
+        if value == '.inf':
+            return sign*self.inf_value
+        elif value == '.nan':
+            return self.nan_value
+        elif ':' in value:
+            digits = [float(part) for part in value.split(':')]
+            digits.reverse()
+            base = 1
+            value = 0.0
+            for digit in digits:
+                value += digit*base
+                base *= 60
+            return sign*value
+        else:
+            return sign*float(value)
+
+    def construct_mapping(self, node, deep=False):
+        if isinstance(node, MappingNode):
+            self.flatten_mapping(node)
+        return super().construct_mapping(node, deep=deep)
 
     def construct_yaml_object(self, node, cls):
         data = cls.__new__(cls)
@@ -423,61 +495,46 @@ def construct_yaml_object(self, node, cls):
             state = self.construct_mapping(node)
             data.__dict__.update(state)
 
-    def construct_undefined(self, node):
-        raise ConstructorError(None, None,
-                "could not determine a constructor for the tag %r" % node.tag,
-                node.start_mark)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:null',
-        SafeConstructor.construct_yaml_null)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:bool',
-        SafeConstructor.construct_yaml_bool)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:int',
-        SafeConstructor.construct_yaml_int)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:float',
-        SafeConstructor.construct_yaml_float)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:binary',
-        SafeConstructor.construct_yaml_binary)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:timestamp',
-        SafeConstructor.construct_yaml_timestamp)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:omap',
-        SafeConstructor.construct_yaml_omap)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:pairs',
-        SafeConstructor.construct_yaml_pairs)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:set',
-        SafeConstructor.construct_yaml_set)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:str',
-        SafeConstructor.construct_yaml_str)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:seq',
-        SafeConstructor.construct_yaml_seq)
-
-SafeConstructor.add_constructor(
-        'tag:yaml.org,2002:map',
-        SafeConstructor.construct_yaml_map)
 
-SafeConstructor.add_constructor(None,
-        SafeConstructor.construct_undefined)
+_yaml11_constructors = {
+                    'str': BaseConstructor.construct_yaml_str,
+                    'seq': BaseConstructor.construct_yaml_seq,
+                    'map': BaseConstructor.construct_yaml_map,
+                    None: BaseConstructor.construct_undefined,
+                    'int': SafeConstructor.construct_yaml_int,
+                    'float': SafeConstructor.construct_yaml_float,
+                    'null': BaseConstructor.construct_yaml_null,
+                    'bool': BaseConstructor.construct_yaml_bool,
+                    'binary': SafeConstructor.construct_yaml_binary,
+                    'timestamp': SafeConstructor.construct_yaml_timestamp,
+                    'omap': SafeConstructor.construct_yaml_omap,
+                    'pairs': SafeConstructor.construct_yaml_pairs,
+                    'set': SafeConstructor.construct_yaml_set,
+                }
+
+_core_constructors = {
+                  'str': BaseConstructor.construct_yaml_str,
+                  'seq': BaseConstructor.construct_yaml_seq,
+                  'map': BaseConstructor.construct_yaml_map,
+                  None: BaseConstructor.construct_undefined,
+                  'int': BaseConstructor.construct_yaml_int_core,
+                  'float': BaseConstructor.construct_yaml_float_core,
+                  'null': BaseConstructor.construct_yaml_null,
+                  'bool': BaseConstructor.construct_yaml_bool,
+              }
+
+_json_constructors = {
+                  'str': BaseConstructor.construct_yaml_str,
+                  'seq': BaseConstructor.construct_yaml_seq,
+                  'map': BaseConstructor.construct_yaml_map,
+                  None: BaseConstructor.construct_undefined,
+                  'int': BaseConstructor.construct_yaml_int_json,
+                  'float': BaseConstructor.construct_yaml_float_json,
+                  'null': BaseConstructor.construct_yaml_null,
+                  'bool': BaseConstructor.construct_yaml_bool,
+              }
+
+SafeConstructor.init_constructors(_yaml11_constructors)
 
 class FullConstructor(SafeConstructor):
     # 'extend' is blacklisted because it is used by
diff --git a/lib/yaml/cyaml.py b/lib/yaml/cyaml.py
index 0c213458..9019209e 100644
--- a/lib/yaml/cyaml.py
+++ b/lib/yaml/cyaml.py
@@ -6,6 +6,7 @@
 
 from yaml._yaml import CParser, CEmitter
 
+from .config import LoaderConfigMixin, DumperConfigMixin
 from .constructor import *
 
 from .serializer import *
@@ -13,7 +14,7 @@
 
 from .resolver import *
 
-class CBaseLoader(CParser, BaseConstructor, BaseResolver):
+class CBaseLoader(CParser, BaseConstructor, BaseResolver, LoaderConfigMixin):
 
     def __init__(self, stream):
         CParser.__init__(self, stream)
@@ -41,7 +42,7 @@ def __init__(self, stream):
         UnsafeConstructor.__init__(self)
         Resolver.__init__(self)
 
-class CLoader(CParser, Constructor, Resolver):
+class CLoader(CParser, Constructor, Resolver, LoaderConfigMixin):
 
     def __init__(self, stream):
         CParser.__init__(self, stream)
@@ -82,7 +83,7 @@ def __init__(self, stream,
                 default_flow_style=default_flow_style, sort_keys=sort_keys)
         Resolver.__init__(self)
 
-class CDumper(CEmitter, Serializer, Representer, Resolver):
+class CDumper(CEmitter, Serializer, Representer, Resolver, DumperConfigMixin):
 
     def __init__(self, stream,
             default_style=None, default_flow_style=False,
diff --git a/lib/yaml/dumper.py b/lib/yaml/dumper.py
index 6aadba55..1c5c236e 100644
--- a/lib/yaml/dumper.py
+++ b/lib/yaml/dumper.py
@@ -1,12 +1,21 @@
 
-__all__ = ['BaseDumper', 'SafeDumper', 'Dumper']
+__all__ = ['BaseDumper', 'SafeDumper', 'Dumper', 'CommonDumper', 'FastestBaseDumper']
 
+from . import tagset
+
+from .config import DumperConfigMixin
 from .emitter import *
 from .serializer import *
 from .representer import *
 from .resolver import *
 
-class BaseDumper(Emitter, Serializer, BaseRepresenter, BaseResolver):
+try:
+    from .cyaml import CDumper as FastestBaseDumper
+except ImportError as ie:
+    FastestBaseDumper = None
+
+
+class BaseDumper(Emitter, Serializer, BaseRepresenter, BaseResolver, DumperConfigMixin):
 
     def __init__(self, stream,
             default_style=None, default_flow_style=False,
@@ -24,7 +33,17 @@ def __init__(self, stream,
                 default_flow_style=default_flow_style, sort_keys=sort_keys)
         Resolver.__init__(self)
 
-class SafeDumper(Emitter, Serializer, SafeRepresenter, Resolver):
+
+if not FastestBaseDumper:
+    # fall back to pure-Python if CBaseDumper is unavailable
+    FastestBaseDumper = BaseDumper
+
+# FIXME: reimplement all these as config calls, eg:
+# SafeDumper = FastestBaseDumper.config(type_name='SafeDumper', tagset=tagset.yaml11)
+
+
+
+class SafeDumper(Emitter, Serializer, SafeRepresenter, Resolver, DumperConfigMixin):
 
     def __init__(self, stream,
             default_style=None, default_flow_style=False,
@@ -42,7 +61,31 @@ def __init__(self, stream,
                 default_flow_style=default_flow_style, sort_keys=sort_keys)
         Resolver.__init__(self)
 
-class Dumper(Emitter, Serializer, Representer, Resolver):
+class CommonDumper(Emitter, Serializer, CommonRepresenter, BaseResolver, DumperConfigMixin):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=False,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None, sort_keys=True):
+        Emitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width,
+                allow_unicode=allow_unicode, line_break=line_break)
+        Serializer.__init__(self, encoding=encoding,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        CommonRepresenter.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style, sort_keys=sort_keys)
+        BaseResolver.__init__(self)
+
+    @classmethod
+    def init_tags(cls, tagset: tagset.TagSet):
+        cls.init_representers(tagset.representers)
+        cls.init_resolvers(tagset.resolvers)
+
+
+class Dumper(Emitter, Serializer, Representer, Resolver, DumperConfigMixin):
 
     def __init__(self, stream,
             default_style=None, default_flow_style=False,
@@ -60,3 +103,8 @@ def __init__(self, stream,
                 default_flow_style=default_flow_style, sort_keys=sort_keys)
         Resolver.__init__(self)
 
+
+_12_CoreDumper = CommonDumper.config(type_name='_12_CoreDumper', tagset=tagset.core)
+_12_JSONDumper = CommonDumper.config(type_name='_12_JSONDumper', tagset=tagset.json)
+
+
diff --git a/lib/yaml/loader.py b/lib/yaml/loader.py
index e90c1122..61ab4c94 100644
--- a/lib/yaml/loader.py
+++ b/lib/yaml/loader.py
@@ -1,15 +1,24 @@
+from __future__ import annotations
 
-__all__ = ['BaseLoader', 'FullLoader', 'SafeLoader', 'Loader', 'UnsafeLoader']
+__all__ = ['BaseLoader', 'FullLoader', 'SafeLoader', 'Loader', 'UnsafeLoader', 'FastestBaseLoader']
 
+from .config import LoaderConfigMixin
 from .reader import *
 from .scanner import *
 from .parser import *
 from .composer import *
 from .constructor import *
 from .resolver import *
+from . import tagset
 
-class BaseLoader(Reader, Scanner, Parser, Composer, BaseConstructor, BaseResolver):
+# FIXME: defer setup to fix circular import
+try:
+    from .cyaml import CBaseLoader as FastestBaseLoader
+except ImportError as ie:
+    FastestBaseLoader = None
 
+
+class BaseLoader(Reader, Scanner, Parser, Composer, BaseConstructor, BaseResolver, LoaderConfigMixin):
     def __init__(self, stream):
         Reader.__init__(self, stream)
         Scanner.__init__(self)
@@ -18,7 +27,24 @@ def __init__(self, stream):
         BaseConstructor.__init__(self)
         BaseResolver.__init__(self)
 
-class FullLoader(Reader, Scanner, Parser, Composer, FullConstructor, Resolver):
+    @classmethod
+    def init_tags(cls, tagset: tagset.TagSet):
+        cls.init_constructors(tagset.constructors)
+        cls.init_resolvers(tagset.resolvers)
+
+
+if not FastestBaseLoader:
+    # fall back to pure Python if CBaseLoader is unavailable
+    FastestBaseLoader = BaseLoader
+
+
+# FIXME: once we fully implement the config stuff, these can all be collapsed to a config call, eg:
+# FullLoader = FastestBaseLoader.config(type_name='FullLoader', tagset=tagset.yaml11 | tagset.python_full)
+# SafeLoader = FastestBaseLoader.config(type_name='SafeLoader', tagset=tagset.yaml11)
+# UnsafeLoader = FastestBaseLoader.config(type_name='UnsafeLoader', tagset=tagset.yaml11 | tagset.python_unsafe)
+# this pattern will also allow a much easier path for users to bolt on default behavior to any old loader
+
+class FullLoader(Reader, Scanner, Parser, Composer, FullConstructor, Resolver, LoaderConfigMixin):
 
     def __init__(self, stream):
         Reader.__init__(self, stream)
@@ -28,7 +54,7 @@ def __init__(self, stream):
         FullConstructor.__init__(self)
         Resolver.__init__(self)
 
-class SafeLoader(Reader, Scanner, Parser, Composer, SafeConstructor, Resolver):
+class SafeLoader(Reader, Scanner, Parser, Composer, SafeConstructor, Resolver, LoaderConfigMixin):
 
     def __init__(self, stream):
         Reader.__init__(self, stream)
@@ -38,7 +64,7 @@ def __init__(self, stream):
         SafeConstructor.__init__(self)
         Resolver.__init__(self)
 
-class Loader(Reader, Scanner, Parser, Composer, Constructor, Resolver):
+class Loader(Reader, Scanner, Parser, Composer, Constructor, Resolver, LoaderConfigMixin):
 
     def __init__(self, stream):
         Reader.__init__(self, stream)
@@ -52,7 +78,7 @@ def __init__(self, stream):
 # untrusted input). Use of either Loader or UnsafeLoader should be rare, since
 # FullLoad should be able to load almost all YAML safely. Loader is left intact
 # to ensure backwards compatibility.
-class UnsafeLoader(Reader, Scanner, Parser, Composer, Constructor, Resolver):
+class UnsafeLoader(Reader, Scanner, Parser, Composer, Constructor, Resolver, LoaderConfigMixin):
 
     def __init__(self, stream):
         Reader.__init__(self, stream)
@@ -61,3 +87,8 @@ def __init__(self, stream):
         Composer.__init__(self)
         Constructor.__init__(self)
         Resolver.__init__(self)
+
+
+_12_CoreLoader = BaseLoader.config(type_name='_12_CoreLoader', tagset=tagset.core)
+_12_JSONLoader = BaseLoader.config(type_name='_12_JSONLoader', tagset=tagset.json)
+
diff --git a/lib/yaml/representer.py b/lib/yaml/representer.py
index 3b0b192e..70905a3c 100644
--- a/lib/yaml/representer.py
+++ b/lib/yaml/representer.py
@@ -1,11 +1,12 @@
 
 __all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer',
-    'RepresenterError']
+    'RepresenterError', 'CommonRepresenter']
 
 from .error import *
 from .nodes import *
 
 import datetime, copyreg, types, base64, collections
+import typing as t
 
 class RepresenterError(YAMLError):
     pass
@@ -131,29 +132,30 @@ def represent_mapping(self, tag, mapping, flow_style=None):
     def ignore_aliases(self, data):
         return False
 
-class SafeRepresenter(BaseRepresenter):
+    def represent_str(self, data):
+        return self.represent_scalar('tag:yaml.org,2002:str', data)
 
-    def ignore_aliases(self, data):
-        if data is None:
-            return True
-        if isinstance(data, tuple) and data == ():
-            return True
-        if isinstance(data, (str, bytes, bool, int, float)):
-            return True
+    def represent_list(self, data):
+        #pairs = (len(data) > 0 and isinstance(data, list))
+        #if pairs:
+        #    for item in data:
+        #        if not isinstance(item, tuple) or len(item) != 2:
+        #            pairs = False
+        #            break
+        #if not pairs:
+            return self.represent_sequence('tag:yaml.org,2002:seq', data)
+        #value = []
+        #for item_key, item_value in data:
+        #    value.append(self.represent_mapping(u'tag:yaml.org,2002:map',
+        #        [(item_key, item_value)]))
+        #return SequenceNode(u'tag:yaml.org,2002:pairs', value)
+
+    def represent_dict(self, data):
+        return self.represent_mapping('tag:yaml.org,2002:map', data)
 
     def represent_none(self, data):
         return self.represent_scalar('tag:yaml.org,2002:null', 'null')
 
-    def represent_str(self, data):
-        return self.represent_scalar('tag:yaml.org,2002:str', data)
-
-    def represent_binary(self, data):
-        if hasattr(base64, 'encodebytes'):
-            data = base64.encodebytes(data).decode('ascii')
-        else:
-            data = base64.encodestring(data).decode('ascii')
-        return self.represent_scalar('tag:yaml.org,2002:binary', data, style='|')
-
     def represent_bool(self, data):
         if data:
             value = 'true'
@@ -184,27 +186,17 @@ def represent_float(self, data):
             # Unfortunately, this is not a valid float representation according
             # to the definition of the `!!float` tag.  We fix this by adding
             # '.0' before the 'e' symbol.
+            # TODO (In YAML 1.2 Core, 1e17 would be a valid float though)
             if '.' not in value and 'e' in value:
                 value = value.replace('e', '.0e', 1)
         return self.represent_scalar('tag:yaml.org,2002:float', value)
 
-    def represent_list(self, data):
-        #pairs = (len(data) > 0 and isinstance(data, list))
-        #if pairs:
-        #    for item in data:
-        #        if not isinstance(item, tuple) or len(item) != 2:
-        #            pairs = False
-        #            break
-        #if not pairs:
-            return self.represent_sequence('tag:yaml.org,2002:seq', data)
-        #value = []
-        #for item_key, item_value in data:
-        #    value.append(self.represent_mapping(u'tag:yaml.org,2002:map',
-        #        [(item_key, item_value)]))
-        #return SequenceNode(u'tag:yaml.org,2002:pairs', value)
-
-    def represent_dict(self, data):
-        return self.represent_mapping('tag:yaml.org,2002:map', data)
+    def represent_binary(self, data):
+        if hasattr(base64, 'encodebytes'):
+            data = base64.encodebytes(data).decode('ascii')
+        else:
+            data = base64.encodestring(data).decode('ascii')
+        return self.represent_scalar('tag:yaml.org,2002:binary', data, style='|')
 
     def represent_set(self, data):
         value = {}
@@ -220,54 +212,90 @@ def represent_datetime(self, data):
         value = data.isoformat(' ')
         return self.represent_scalar('tag:yaml.org,2002:timestamp', value)
 
-    def represent_yaml_object(self, tag, data, cls, flow_style=None):
-        if hasattr(data, '__getstate__'):
-            state = data.__getstate__()
-        else:
-            state = data.__dict__.copy()
-        return self.represent_mapping(tag, state, flow_style=flow_style)
-
     def represent_undefined(self, data):
         raise RepresenterError("cannot represent an object", data)
 
-SafeRepresenter.add_representer(type(None),
-        SafeRepresenter.represent_none)
-
-SafeRepresenter.add_representer(str,
-        SafeRepresenter.represent_str)
-
-SafeRepresenter.add_representer(bytes,
-        SafeRepresenter.represent_binary)
-
-SafeRepresenter.add_representer(bool,
-        SafeRepresenter.represent_bool)
-
-SafeRepresenter.add_representer(int,
-        SafeRepresenter.represent_int)
-
-SafeRepresenter.add_representer(float,
-        SafeRepresenter.represent_float)
+    @classmethod
+    def init_representers(cls, tagset_representers: dict[str, t.Callable]):
+        for type_name, representer in tagset_representers.items():
+            cls.add_representer(type_name, representer)
 
-SafeRepresenter.add_representer(list,
-        SafeRepresenter.represent_list)
+class CommonRepresenter(BaseRepresenter):
 
-SafeRepresenter.add_representer(tuple,
-        SafeRepresenter.represent_list)
+    def ignore_aliases(self, data):
+        if data is None:
+            return True
+        if isinstance(data, tuple) and data == ():
+            return True
+        if isinstance(data, (str, bytes, bool, int, float)):
+            return True
 
-SafeRepresenter.add_representer(dict,
-        SafeRepresenter.represent_dict)
+    def represent_yaml_object(self, tag, data, cls, flow_style=None):
+        if hasattr(data, '__getstate__'):
+            state = data.__getstate__()
+        else:
+            state = data.__dict__.copy()
+        return self.represent_mapping(tag, state, flow_style=flow_style)
 
-SafeRepresenter.add_representer(set,
-        SafeRepresenter.represent_set)
+class SafeRepresenter(BaseRepresenter):
 
-SafeRepresenter.add_representer(datetime.date,
-        SafeRepresenter.represent_date)
+    def ignore_aliases(self, data):
+        if data is None:
+            return True
+        if isinstance(data, tuple) and data == ():
+            return True
+        if isinstance(data, (str, bytes, bool, int, float)):
+            return True
 
-SafeRepresenter.add_representer(datetime.datetime,
-        SafeRepresenter.represent_datetime)
+    def represent_yaml_object(self, tag, data, cls, flow_style=None):
+        if hasattr(data, '__getstate__'):
+            state = data.__getstate__()
+        else:
+            state = data.__dict__.copy()
+        return self.represent_mapping(tag, state, flow_style=flow_style)
 
-SafeRepresenter.add_representer(None,
-        SafeRepresenter.represent_undefined)
+_representers = {
+    'yaml11': {
+        bool: BaseRepresenter.represent_bool,
+        dict: BaseRepresenter.represent_dict,
+        list: BaseRepresenter.represent_list,
+        tuple: BaseRepresenter.represent_list,
+        str: BaseRepresenter.represent_str,
+        float: BaseRepresenter.represent_float,
+        int: BaseRepresenter.represent_int,
+        type(None): BaseRepresenter.represent_none,
+        bytes: BaseRepresenter.represent_binary,
+        set: BaseRepresenter.represent_set,
+        datetime.date: BaseRepresenter.represent_date,
+        datetime.datetime: BaseRepresenter.represent_datetime,
+        None: BaseRepresenter.represent_undefined,
+    },
+    'core': {
+        bool: BaseRepresenter.represent_bool,
+        dict: BaseRepresenter.represent_dict,
+        list: BaseRepresenter.represent_list,
+        tuple: BaseRepresenter.represent_list,
+        str: BaseRepresenter.represent_str,
+        float: BaseRepresenter.represent_float,
+        int: BaseRepresenter.represent_int,
+        type(None): BaseRepresenter.represent_none,
+        None: BaseRepresenter.represent_undefined,
+    },
+    'json': {
+        bool: BaseRepresenter.represent_bool,
+        dict: BaseRepresenter.represent_dict,
+        list: BaseRepresenter.represent_list,
+        tuple: BaseRepresenter.represent_list,
+        str: BaseRepresenter.represent_str,
+        float: BaseRepresenter.represent_float,
+        int: BaseRepresenter.represent_int,
+        type(None): BaseRepresenter.represent_none,
+        None: BaseRepresenter.represent_undefined,
+    },
+}
+
+
+SafeRepresenter.init_representers(_representers['yaml11'])
 
 class Representer(SafeRepresenter):
 
@@ -369,7 +397,7 @@ def represent_ordered_dict(self, data):
 Representer.add_representer(tuple,
         Representer.represent_tuple)
 
-Representer.add_representer(type,
+Representer.add_multi_representer(type,
         Representer.represent_name)
 
 Representer.add_representer(collections.OrderedDict,
diff --git a/lib/yaml/resolver.py b/lib/yaml/resolver.py
index 013896d2..e85500d7 100644
--- a/lib/yaml/resolver.py
+++ b/lib/yaml/resolver.py
@@ -1,10 +1,11 @@
 
 __all__ = ['BaseResolver', 'Resolver']
 
+import re
+
 from .error import *
 from .nodes import *
 
-import re
 
 class ResolverError(YAMLError):
     pass
@@ -164,64 +165,102 @@ def resolve(self, kind, value, implicit):
         elif kind is MappingNode:
             return self.DEFAULT_MAPPING_TAG
 
-class Resolver(BaseResolver):
-    pass
+    @classmethod
+    def init_resolvers(cls, implicit_resolvers: list[list]):
+        # FIXME: factor this out as a config mixin with dataclasses
+        for args in implicit_resolvers:
+            cls.add_implicit_resolver(
+                'tag:yaml.org,2002:' + args[0],
+                args[1], args[2]
+            )
+
+
+
+# FIXME: come up with a better way to lazy init these so we can define all the well-known stuff in one place
+# avoid circular import by defining here for now
+_yaml11_resolvers = [
+    ['bool',
+     re.compile(r'''^(?:yes|Yes|YES|no|No|NO
+                |true|True|TRUE|false|False|FALSE
+                |on|On|ON|off|Off|OFF)$''', re.X),
+     list('yYnNtTfFoO')],
+    ['float',
+     re.compile(r'''^(?:[-+]?(?:[0-9][0-9_]*)\.[0-9_]*(?:[eE][-+][0-9]+)?
+                |\.[0-9_]+(?:[eE][-+][0-9]+)?
+                |[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\.[0-9_]*
+                |[-+]?\.(?:inf|Inf|INF)
+                |\.(?:nan|NaN|NAN))$''', re.X),
+     list('-+0123456789.')],
+    ['int',
+     re.compile(r'''^(?:[-+]?0b[0-1_]+
+                |[-+]?0[0-7_]+
+                |[-+]?(?:0|[1-9][0-9_]*)
+                |[-+]?0x[0-9a-fA-F_]+
+                |[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
+     list('-+0123456789')],
+    ['merge',
+     re.compile(r'^(?:<<)$'),
+     ['<']],
+    ['null',
+     re.compile(r'''^(?: ~
+                |null|Null|NULL
+                | )$''', re.X),
+     ['~', 'n', 'N', '']],
+    ['timestamp',
+     re.compile(r'''^(?:[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]
+                |[0-9][0-9][0-9][0-9] -[0-9][0-9]? -[0-9][0-9]?
+                 (?:[Tt]|[ \t]+)[0-9][0-9]?
+                 :[0-9][0-9] :[0-9][0-9] (?:\.[0-9]*)?
+                 (?:[ \t]*(?:Z|[-+][0-9][0-9]?(?::[0-9][0-9])?))?)$''', re.X),
+     list('0123456789')],
+    ['value',
+     re.compile(r'^(?:=)$'),
+     ['=']],
+    # The following resolver is only for documentation purposes. It cannot work
+    # because plain scalars cannot start with '!', '&', or '*'.
+    ['yaml',
+     re.compile(r'^(?:!|&|\*)$'),
+     list('!&*')],
+]
+
+_core_resolvers = [
+                  ['bool',
+                   re.compile(r'''^(?:|true|True|TRUE|false|False|FALSE)$''', re.X),
+                   list('tTfF')],
+                  ['int',
+                   re.compile(r'''^(?:
+                              |0o[0-7]+
+                              |[-+]?(?:[0-9]+)
+                              |0x[0-9a-fA-F]+
+                              )$''', re.X),
+                   list('-+0123456789')],
+                  ['float',
+                   re.compile(r'''^(?:[-+]?(?:\.[0-9]+|[0-9]+(\.[0-9]*)?)(?:[eE][-+]?[0-9]+)?
+                              |[-+]?\.(?:inf|Inf|INF)
+                              |\.(?:nan|NaN|NAN))$''', re.X),
+                   list('-+0123456789.')],
+                  ['null',
+                   re.compile(r'''^(?:~||null|Null|NULL)$''', re.X),
+                   ['~', 'n', 'N', '']],
+              ]
+
+_json_resolvers = [
+                  ['bool',
+                   re.compile(r'''^(?:true|false)$''', re.X),
+                   list('tf')],
+                  ['int',
+                   re.compile(r'''^-?(?:0|[1-9][0-9]*)$''', re.X),
+                   list('-0123456789')],
+                  ['float',
+                   re.compile(r'''^-?(?:0|[1-9][0-9]*)(\.[0-9]*)?(?:[eE][-+]?[0-9]+)?$''', re.X),
+                   list('-0123456789.')],
+                  ['null',
+                   re.compile(r'''^null$''', re.X),
+                   ['n']],
+              ]
+
+class Resolver(BaseResolver): pass
 
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:bool',
-        re.compile(r'''^(?:yes|Yes|YES|no|No|NO
-                    |true|True|TRUE|false|False|FALSE
-                    |on|On|ON|off|Off|OFF)$''', re.X),
-        list('yYnNtTfFoO'))
-
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:float',
-        re.compile(r'''^(?:[-+]?(?:[0-9][0-9_]*)\.[0-9_]*(?:[eE][-+][0-9]+)?
-                    |\.[0-9_]+(?:[eE][-+][0-9]+)?
-                    |[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\.[0-9_]*
-                    |[-+]?\.(?:inf|Inf|INF)
-                    |\.(?:nan|NaN|NAN))$''', re.X),
-        list('-+0123456789.'))
-
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:int',
-        re.compile(r'''^(?:[-+]?0b[0-1_]+
-                    |[-+]?0[0-7_]+
-                    |[-+]?(?:0|[1-9][0-9_]*)
-                    |[-+]?0x[0-9a-fA-F_]+
-                    |[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
-        list('-+0123456789'))
-
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:merge',
-        re.compile(r'^(?:<<)$'),
-        ['<'])
-
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:null',
-        re.compile(r'''^(?: ~
-                    |null|Null|NULL
-                    | )$''', re.X),
-        ['~', 'n', 'N', ''])
-
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:timestamp',
-        re.compile(r'''^(?:[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]
-                    |[0-9][0-9][0-9][0-9] -[0-9][0-9]? -[0-9][0-9]?
-                     (?:[Tt]|[ \t]+)[0-9][0-9]?
-                     :[0-9][0-9] :[0-9][0-9] (?:\.[0-9]*)?
-                     (?:[ \t]*(?:Z|[-+][0-9][0-9]?(?::[0-9][0-9])?))?)$''', re.X),
-        list('0123456789'))
-
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:value',
-        re.compile(r'^(?:=)$'),
-        ['='])
-
-# The following resolver is only for documentation purposes. It cannot work
-# because plain scalars cannot start with '!', '&', or '*'.
-Resolver.add_implicit_resolver(
-        'tag:yaml.org,2002:yaml',
-        re.compile(r'^(?:!|&|\*)$'),
-        list('!&*'))
+# FIXME: config mixin or defer this to loader setup via config?
+Resolver.init_resolvers(_yaml11_resolvers)
 
diff --git a/lib/yaml/tagset.py b/lib/yaml/tagset.py
new file mode 100644
index 00000000..f04d78aa
--- /dev/null
+++ b/lib/yaml/tagset.py
@@ -0,0 +1,37 @@
+import re
+import typing as t
+
+from dataclasses import dataclass
+# FIXME: disentangle various class inits so we can define these all together
+from .constructor import _core_constructors, _json_constructors, _yaml11_constructors
+from .representer import _representers  # FIXME make consistent
+from .resolver import _core_resolvers, _json_resolvers, _yaml11_resolvers
+
+# FIXME: restructure these as dataclasses for each type that are individually accessible to make it easier to build up a custom tag set with well-known types
+
+# FIXME: add Python tags here as well
+
+@dataclass
+class TagSet:
+    name: str
+    constructors: dict[str, t.Callable]  # FIXME: implement constructor dataclass?
+    representers: dict[str, t.Callable]  # FIXME: implement representer dataclass?
+    resolvers: list[list]  # FIXME: implement ImplicitResolver dataclass
+    # FIXME: add support for multi/implicit constructors, representers, resolvers, etc?
+
+
+yaml11 = TagSet(name='yaml11',
+                constructors=_yaml11_constructors,
+                representers=_representers['yaml11'],
+                resolvers=_yaml11_resolvers)
+
+core = TagSet(name='core',
+              constructors=_core_constructors,
+              representers=_representers['core'],
+              resolvers=_core_resolvers)
+
+json = TagSet(name='json',
+              constructors=_json_constructors,
+              representers=_representers['json'],
+              resolvers=_json_resolvers)
+
diff --git a/tests/data/construct-python-name-module.code b/tests/data/construct-python-name-module.code
index 6f391488..b8a4b6f8 100644
--- a/tests/data/construct-python-name-module.code
+++ b/tests/data/construct-python-name-module.code
@@ -1 +1 @@
-[str, yaml.Loader, yaml.dump, abs, yaml.tokens]
+[str, yaml.Loader, yaml.dump, abs, yaml.tokens, signal.Handlers]
diff --git a/tests/data/construct-python-name-module.data b/tests/data/construct-python-name-module.data
index f0c9712b..f1a2c24a 100644
--- a/tests/data/construct-python-name-module.data
+++ b/tests/data/construct-python-name-module.data
@@ -3,3 +3,4 @@
 - !!python/name:yaml.dump
 - !!python/name:abs
 - !!python/module:yaml.tokens
+- !!python/name:signal.Handlers
diff --git a/tests/data/core.schema b/tests/data/core.schema
new file mode 100644
index 00000000..f830a277
--- /dev/null
+++ b/tests/data/core.schema
@@ -0,0 +1,235 @@
+# https://github.com/perlpunk/yaml-test-schema/blob/master/data/schema-core.yaml
+---
+'!!bool FALSE': ['bool', 'false()', 'false']
+'!!bool False': ['bool', 'false()', 'false']
+'!!bool TRUE': ['bool', 'true()', 'true']
+'!!bool True': ['bool', 'true()', 'true']
+'!!bool false': ['bool', 'false()', 'false']
+'!!bool true': ['bool', 'true()', 'true']
+'!!float +.INF': ['inf', 'inf()', '.inf']
+'!!float +.Inf': ['inf', 'inf()', '.inf']
+'!!float +.inf': ['inf', 'inf()', '.inf']
+'!!float +0.3e+3': ['float', '300.0', '300.0']
+'!!float +0.3e3': ['float', '300.0', '300.0']
+'!!float -.INF': ['inf', 'inf-neg()', '-.inf']
+'!!float -.Inf': ['inf', 'inf-neg()', '-.inf']
+'!!float -.inf': ['inf', 'inf-neg()', '-.inf']
+'!!float -3.14': ['float', '-3.14', '-3.14']
+'!!float .0': ['float', '0.0', '0.0']
+'!!float .14': ['float', '0.14', '0.14']
+'!!float .3E-1': ['float', '0.03', '0.03']
+'!!float .3e+3': ['float', '300.0', '300.0']
+'!!float .3e3': ['float', '300.0', '300.0']
+'!!float .INF': ['inf', 'inf()', '.inf']
+'!!float .Inf': ['inf', 'inf()', '.inf']
+'!!float .NAN': ['nan', 'nan()', '.nan']
+'!!float .NaN': ['nan', 'nan()', '.nan']
+'!!float .inf': ['inf', 'inf()', '.inf']
+'!!float .nan': ['nan', 'nan()', '.nan']
+'!!float 0.0': ['float', '0.0', '0.0']
+'!!float 0.3e3': ['float', '300.0', '300.0']
+'!!float 001.23': ['float', '1.23', '1.23']
+'!!float 3.': ['float', '3.0', '3.0']
+'!!float 3.14': ['float', '3.14', '3.14']
+'!!float 3.3e+3': ['float', '3300.0', '3300.0']
+'!!int +0': ['int', '0', '0']
+'!!int +23': ['int', '23', '23']
+'!!int -0': ['int', '0', '0']
+'!!int -23': ['int', '-23', '-23']
+'!!int 0': ['int', '0', '0']
+'!!int 0011': ['int', '11', '11']
+'!!int 07': ['int', '7', '7']
+'!!int 0o0': ['int', '0', '0']
+'!!int 0o10': ['int', '8', '8']
+'!!int 0o7': ['int', '7', '7']
+'!!int 0x0': ['int', '0', '0']
+'!!int 0x10': ['int', '16', '16']
+'!!int 0x42': ['int', '66', '66']
+'!!int 0xa': ['int', '10', '10']
+'!!int 23': ['int', '23', '23']
+'!!null #empty': ['null', 'null()', "null"]
+'!!null NULL': ['null', 'null()', "null"]
+'!!null Null': ['null', 'null()', "null"]
+'!!null null': ['null', 'null()', 'null']
+'!!null ~': ['null', 'null()', 'null']
+'!!str #empty': ['str', '', "''"]
+'!!str +.INF': ['str', '+.INF', "'+.INF'"]
+'!!str +.Inf': ['str', '+.Inf', "'+.Inf'"]
+'!!str +.inf': ['str', '+.inf', "'+.inf'"]
+'!!str +0': ['str', '+0', "'+0'"]
+'!!str +0.3e+3': ['str', '+0.3e+3', "'+0.3e+3'"]
+'!!str +0.3e3': ['str', '+0.3e3', "'+0.3e3'"]
+'!!str +0100_200': ['str', '+0100_200', "+0100_200"]
+'!!str +0b100': ['str', '+0b100', "+0b100"]
+'!!str +190:20:30': ['str', '+190:20:30', "+190:20:30"]
+'!!str +23': ['str', '+23', "'+23'"]
+'!!str -.INF': ['str', '-.INF', "'-.INF'"]
+'!!str -.Inf': ['str', '-.Inf', "'-.Inf'"]
+'!!str -.inf': ['str', '-.inf', "'-.inf'"]
+'!!str -0': ['str', '-0', "'-0'"]
+'!!str -0100_200': ['str', '-0100_200', "-0100_200"]
+'!!str -0b101': ['str', '-0b101', "-0b101"]
+'!!str -0x30': ['str', '-0x30', "-0x30"]
+'!!str -190:20:30': ['str', '-190:20:30', "-190:20:30"]
+'!!str -23': ['str', '-23', "'-23'"]
+'!!str -3.14': ['str', '-3.14', "'-3.14'"]
+'!!str .': ['str', '.', '.']
+'!!str .0': ['str', '.0', "'.0'"]
+'!!str .14': ['str', '.14', "'.14'"]
+'!!str .1_4': ['str', '.1_4', '.1_4']
+'!!str .3E-1': ['str', '.3E-1', "'.3E-1'"]
+'!!str .3e+3': ['str', '.3e+3', "'.3e+3'"]
+'!!str .3e3': ['str', '.3e3', "'.3e3'"]
+'!!str .INF': ['str', '.INF', "'.INF'"]
+'!!str .Inf': ['str', '.Inf', "'.Inf'"]
+'!!str .NAN': ['str', '.NAN', "'.NAN'"]
+'!!str .NaN': ['str', '.NaN', "'.NaN'"]
+'!!str ._': ['str', '._', '._']
+'!!str ._14': ['str', '._14', '._14']
+'!!str .inf': ['str', '.inf', "'.inf'"]
+'!!str .nan': ['str', '.nan', "'.nan'"]
+'!!str 0': ['str', '0', "'0'"]
+'!!str 0.0': ['str', '0.0', "'0.0'"]
+'!!str 0.3e3': ['str', '0.3e3', "'0.3e3'"]
+'!!str 00': ['str', '00', "'00'"]
+'!!str 001.23': ['str', '001.23', "'001.23'"]
+'!!str 0011': ['str', '0011', "'0011'"]
+'!!str 010': ['str', '010', "'010'"]
+'!!str 02_0': ['str', '02_0', "02_0"]
+'!!str 07': ['str', '07', "'07'"]
+'!!str 0b0': ['str', '0b0', "0b0"]
+'!!str 0b100_101': ['str', '0b100_101', "0b100_101"]
+'!!str 0o0': ['str', '0o0', "'0o0'"]
+'!!str 0o10': ['str', '0o10', "'0o10'"]
+'!!str 0o7': ['str', '0o7', "'0o7'"]
+'!!str 0x0': ['str', '0x0', "'0x0'"]
+'!!str 0x2_0': ['str', '0x2_0', "0x2_0"]
+'!!str 0xa': ['str', '0xa', "'0xa'"]
+'!!str 100_000': ['str', '100_000', "100_000"]
+'!!str 190:20:30': ['str', '190:20:30', "190:20:30"]
+'!!str 190:20:30.15': ['str', '190:20:30.15', "190:20:30.15"]
+'!!str 23': ['str', '23', "'23'"]
+'!!str 3.': ['str', '3.', "'3.'"]
+'!!str 3.14': ['str', '3.14', "'3.14'"]
+'!!str 3.3e+3': ['str', '3.3e+3', "'3.3e+3'"]
+'!!str 85.230_15e+03': ['str', '85.230_15e+03', "85.230_15e+03"]
+'!!str 85_230.15': ['str', '85_230.15', "85_230.15"]
+'!!str FALSE': ['str', 'FALSE', "'FALSE'"]
+'!!str False': ['str', 'False', "'False'"]
+'!!str N': ['str', 'N', "N"]
+'!!str NO': ['str', 'NO', "NO"]
+'!!str NULL': ['str', 'NULL', "'NULL'"]
+'!!str Null': ['str', 'Null', "'Null'"]
+'!!str OFF': ['str', 'OFF', "OFF"]
+'!!str ON': ['str', 'ON', "ON"]
+'!!str Off': ['str', 'Off', "Off"]
+'!!str On': ['str', 'On', "On"]
+'!!str TRUE': ['str', 'TRUE', "'TRUE'"]
+'!!str True': ['str', 'True', "'True'"]
+'!!str Y': ['str', 'Y', "Y"]
+'!!str YES': ['str', 'YES', "YES"]
+'!!str Yes': ['str', 'Yes', "Yes"]
+'!!str _._': ['str', '_._', '_._']
+'!!str false': ['str', 'false', "'false'"]
+'!!str n': ['str', 'n', "n"]
+'!!str no': ['str', 'no', "no"]
+'!!str null': ['str', 'null', "'null'"]
+'!!str off': ['str', 'off', "off"]
+'!!str on': ['str', 'on', "on"]
+'!!str true': ['str', 'true', "'true'"]
+'!!str y': ['str', 'y', "y"]
+'!!str yes': ['str', 'yes', "yes"]
+'!!str ~': ['str', '~', "'~'"]
+'#empty': ['null', 'null()', "null"]
+'+.INF': ['inf', 'inf()', '.inf']
+'+.Inf': ['inf', 'inf()', '.inf']
+'+.inf': ['inf', 'inf()', '.inf']
+'+0': ['int', '0', '0']
+'+0.3e+3': ['float', '300.0', '300.0']
+'+0.3e3': ['float', '300.0', '300.0']
+'+0100_200': ['str', '+0100_200', '+0100_200']
+'+0b100': ['str', '+0b100', '+0b100']
+'+190:20:30': ['str', '+190:20:30', '+190:20:30']
+'+23': ['int', '23', '23']
+'+3.14': ['float', '3.14', '3.14']
+'-.INF': ['inf', 'inf-neg()', '-.inf']
+'-.Inf': ['inf', 'inf-neg()', '-.inf']
+'-.inf': ['inf', 'inf-neg()', '-.inf']
+'-0': ['int', '0', '0']
+'-0100_200': ['str', '-0100_200', '-0100_200']
+'-0b101': ['str', '-0b101', '-0b101']
+'-0x30': ['str', '-0x30', '-0x30']
+'-190:20:30': ['str', '-190:20:30', '-190:20:30']
+'-23': ['int', '-23', '-23']
+'-3.14': ['float', '-3.14', '-3.14']
+'.': ['str', '.', '.']
+'.0': ['float', '0.0', '0.0']
+'.14': ['float', '0.14', '0.14']
+'.1_4': ['str', '.1_4', '.1_4']
+'.3E-1': ['float', '0.03', '0.03']
+'.3e+3': ['float', '300.0', '300.0']
+'.3e3': ['float', '300.0', '300.0']
+'.INF': ['inf', 'inf()', '.inf']
+'.Inf': ['inf', 'inf()', '.inf']
+'.NAN': ['nan', 'nan()', '.nan']
+'.NaN': ['nan', 'nan()', '.nan']
+'._': ['str', '._', '._']
+'._14': ['str', '._14', '._14']
+'.inf': ['inf', 'inf()', '.inf']
+'.nan': ['nan', 'nan()', '.nan']
+'0': ['int', '0', '0']
+'0.0': ['float', '0.0', '0.0']
+'0.3e3': ['float', '300.0', '300.0']
+'00': ['int', '0', '0']
+'001.23': ['float', '1.23', '1.23']
+'0011': ['int', '11', '11']
+'010': ['int', '10', '10']
+'02_0': ['str', '02_0', '02_0']
+'07': ['int', '7', '7']
+'08': ['int', '8', '8']
+'0b0': ['str', '0b0', '0b0']
+'0b100_101': ['str', '0b100_101', '0b100_101']
+'0o0': ['int', '0', '0']
+'0o10': ['int', '8', '8']
+'0o7': ['int', '7', '7']
+'0x0': ['int', '0', '0']
+'0x10': ['int', '16', '16']
+'0x2_0': ['str', '0x2_0', '0x2_0']
+'0x42': ['int', '66', '66']
+'0xa': ['int', '10', '10']
+'100_000': ['str', '100_000', '100_000']
+'190:20:30': ['str', '190:20:30', '190:20:30']
+'190:20:30.15': ['str', '190:20:30.15', '190:20:30.15']
+'23': ['int', '23', '23']
+'3.': ['float', '3.0', '3.0']
+'3.14': ['float', '3.14', '3.14']
+'3.3e+3': ['float', '3300', '3300.0']
+'3e3': ['float', '3000', '3000.0']
+'85.230_15e+03': ['str', '85.230_15e+03', '85.230_15e+03']
+'85_230.15': ['str', '85_230.15', '85_230.15']
+'FALSE': ['bool', 'false()', 'false']
+'False': ['bool', 'false()', 'false']
+'N': ['str', 'N', "N"]
+'NO': ['str', 'NO', "NO"]
+'NULL': ['null', 'null()', "null"]
+'Null': ['null', 'null()', "null"]
+'OFF': ['str', 'OFF', "OFF"]
+'ON': ['str', 'ON', "ON"]
+'Off': ['str', 'Off', "Off"]
+'On': ['str', 'On', "On"]
+'TRUE': ['bool', 'true()', 'true']
+'True': ['bool', 'true()', 'true']
+'Y': ['str', 'Y', "Y"]
+'YES': ['str', 'YES', "YES"]
+'Yes': ['str', 'Yes', "Yes"]
+'_._': ['str', '_._', '_._']
+'false': ['bool', 'false()', 'false']
+'n': ['str', 'n', "n"]
+'no': ['str', 'no', "no"]
+'null': ['null', 'null()', "null"]
+'off': ['str', 'off', "off"]
+'on': ['str', 'on', "on"]
+'true': ['bool', 'true()', 'true']
+'y': ['str', 'y', "y"]
+'yes': ['str', 'yes', "yes"]
+'~': ['null', 'null()', "null"]
diff --git a/tests/data/core.schema-skip b/tests/data/core.schema-skip
new file mode 100644
index 00000000..d412d083
--- /dev/null
+++ b/tests/data/core.schema-skip
@@ -0,0 +1,4 @@
+load: {
+  }
+dump: {
+  }
diff --git a/tests/data/json.schema b/tests/data/json.schema
new file mode 100644
index 00000000..676f2909
--- /dev/null
+++ b/tests/data/json.schema
@@ -0,0 +1,195 @@
+# https://github.com/perlpunk/yaml-test-schema/blob/master/data/schema-json.yaml
+---
+'!!bool false': ['bool', 'false()', 'false']
+'!!bool true': ['bool', 'true()', 'true']
+'!!float -3.14': ['float', '-3.14', '-3.14']
+'!!float 0.0': ['float', '0.0', '0.0']
+'!!float 0.3e3': ['float', '300.0', '300.0']
+'!!float 3.': ['float', '3.0', '3.0']
+'!!float 3.14': ['float', '3.14', '3.14']
+'!!int -0': ['int', '0', '0']
+'!!int -23': ['int', '-23', '-23']
+'!!int 0': ['int', '0', '0']
+'!!int 23': ['int', '23', '23']
+'!!null null': ['null', 'null()', 'null']
+'!!str #empty': ['str', '', "''"]
+'!!str +.INF': ['str', '+.INF', "+.INF"]
+'!!str +.Inf': ['str', '+.Inf', "+.Inf"]
+'!!str +.inf': ['str', '+.inf', "+.inf"]
+'!!str +0': ['str', '+0', "+0"]
+'!!str +0.3e+3': ['str', '+0.3e+3', "+0.3e+3"]
+'!!str +0.3e3': ['str', '+0.3e3', "+0.3e3"]
+'!!str +0100_200': ['str', '+0100_200', "+0100_200"]
+'!!str +0b100': ['str', '+0b100', "+0b100"]
+'!!str +190:20:30': ['str', '+190:20:30', "+190:20:30"]
+'!!str +23': ['str', '+23', "+23"]
+'!!str -.INF': ['str', '-.INF', "-.INF"]
+'!!str -.Inf': ['str', '-.Inf', "-.Inf"]
+'!!str -.inf': ['str', '-.inf', "-.inf"]
+'!!str -0': ['str', '-0', "'-0'"]
+'!!str -0100_200': ['str', '-0100_200', "-0100_200"]
+'!!str -0b101': ['str', '-0b101', "-0b101"]
+'!!str -0x30': ['str', '-0x30', "-0x30"]
+'!!str -190:20:30': ['str', '-190:20:30', "-190:20:30"]
+'!!str -23': ['str', '-23', "'-23'"]
+'!!str -3.14': ['str', '-3.14', "'-3.14'"]
+'!!str .': ['str', '.', '.']
+'!!str .0': ['str', '.0', ".0"]
+'!!str .14': ['str', '.14', '.14']
+'!!str .1_4': ['str', '.1_4', '.1_4']
+'!!str .3E-1': ['str', '.3E-1', ".3E-1"]
+'!!str .3e+3': ['str', '.3e+3', ".3e+3"]
+'!!str .3e3': ['str', '.3e3', ".3e3"]
+'!!str .INF': ['str', '.INF', ".INF"]
+'!!str .Inf': ['str', '.Inf', ".Inf"]
+'!!str .NAN': ['str', '.NAN', ".NAN"]
+'!!str .NaN': ['str', '.NaN', ".NaN"]
+'!!str ._': ['str', '._', '._']
+'!!str ._14': ['str', '._14', '._14']
+'!!str .inf': ['str', '.inf', ".inf"]
+'!!str .nan': ['str', '.nan', ".nan"]
+'!!str 0': ['str', '0', "'0'"]
+'!!str 0.0': ['str', '0.0', "'0.0'"]
+'!!str 0.3e3': ['str', '0.3e3', "'0.3e3'"]
+'!!str 00': ['str', '00', "00"]
+'!!str 001.23': ['str', '001.23', "001.23"]
+'!!str 0011': ['str', '0011', "0011"]
+'!!str 010': ['str', '010', "010"]
+'!!str 02_0': ['str', '02_0', "02_0"]
+'!!str 07': ['str', '07', "07"]
+'!!str 0b0': ['str', '0b0', "0b0"]
+'!!str 0b100_101': ['str', '0b100_101', "0b100_101"]
+'!!str 0o0': ['str', '0o0', "0o0"]
+'!!str 0o10': ['str', '0o10', "0o10"]
+'!!str 0o7': ['str', '0o7', "0o7"]
+'!!str 0x0': ['str', '0x0', "0x0"]
+'!!str 0x2_0': ['str', '0x2_0', "0x2_0"]
+'!!str 0xa': ['str', '0xa', "0xa"]
+'!!str 100_000': ['str', '100_000', "100_000"]
+'!!str 190:20:30': ['str', '190:20:30', "190:20:30"]
+'!!str 190:20:30.15': ['str', '190:20:30.15', "190:20:30.15"]
+'!!str 23': ['str', '23', "'23'"]
+'!!str 3.': ['str', '3.', "'3.'"]
+'!!str 3.14': ['str', '3.14', "'3.14'"]
+'!!str 3.3e+3': ['str', '3.3e+3', "'3.3e+3'"]
+'!!str 85.230_15e+03': ['str', '85.230_15e+03', "85.230_15e+03"]
+'!!str 85_230.15': ['str', '85_230.15', "85_230.15"]
+'!!str FALSE': ['str', 'FALSE', "FALSE"]
+'!!str False': ['str', 'False', "False"]
+'!!str N': ['str', 'N', "N"]
+'!!str NO': ['str', 'NO', "NO"]
+'!!str NULL': ['str', 'NULL', "NULL"]
+'!!str Null': ['str', 'Null', "Null"]
+'!!str OFF': ['str', 'OFF', "OFF"]
+'!!str ON': ['str', 'ON', "ON"]
+'!!str Off': ['str', 'Off', "Off"]
+'!!str On': ['str', 'On', "On"]
+'!!str TRUE': ['str', 'TRUE', 'TRUE']
+'!!str True': ['str', 'True', 'True']
+'!!str Y': ['str', 'Y', "Y"]
+'!!str YES': ['str', 'YES', "YES"]
+'!!str Yes': ['str', 'Yes', "Yes"]
+'!!str _._': ['str', '_._', '_._']
+'!!str false': ['str', 'false', "'false'"]
+'!!str n': ['str', 'n', "n"]
+'!!str no': ['str', 'no', "no"]
+'!!str null': ['str', 'null', "'null'"]
+'!!str off': ['str', 'off', "off"]
+'!!str on': ['str', 'on', "on"]
+'!!str true': ['str', 'true', "'true'"]
+'!!str y': ['str', 'y', "y"]
+'!!str yes': ['str', 'yes', "yes"]
+'!!str ~': ['str', '~', '~']
+'#empty': ['str', '', "''"]
+'+.INF': ['str', '+.INF', '+.INF']
+'+.Inf': ['str', '+.Inf', '+.Inf']
+'+.inf': ['str', '+.inf', '+.inf']
+'+0': ['str', '+0', '+0']
+'+0.3e+3': ['str', '+0.3e+3', '+0.3e+3']
+'+0.3e3': ['str', '+0.3e3', '+0.3e3']
+'+0100_200': ['str', '+0100_200', '+0100_200']
+'+0b100': ['str', '+0b100', '+0b100']
+'+190:20:30': ['str', '+190:20:30', '+190:20:30']
+'+23': ['str', '+23', '+23']
+'+3.14': ['str', '+3.14', '+3.14']
+'-.INF': ['str', '-.INF', '-.INF']
+'-.Inf': ['str', '-.Inf', '-.Inf']
+'-.inf': ['str', '-.inf', '-.inf']
+'-0': ['int', '0', '0']
+'-0100_200': ['str', '-0100_200', '-0100_200']
+'-0b101': ['str', '-0b101', '-0b101']
+'-0x30': ['str', '-0x30', '-0x30']
+'-190:20:30': ['str', '-190:20:30', '-190:20:30']
+'-23': ['int', '-23', '-23']
+'-3.14': ['float', '-3.14', '-3.14']
+'.': ['str', '.', '.']
+'.0': ['str', '.0', '.0']
+'.14': ['str', '.14', '.14']
+'.1_4': ['str', '.1_4', '.1_4']
+'.3E-1': ['str', '.3E-1', '.3E-1']
+'.3e+3': ['str', '.3e+3', '.3e+3']
+'.3e3': ['str', '.3e3', '.3e3']
+'.INF': ['str', '.INF', '.INF']
+'.Inf': ['str', '.Inf', '.Inf']
+'.NAN': ['str', '.NAN', '.NAN']
+'.NaN': ['str', '.NaN', '.NaN']
+'._': ['str', '._', '._']
+'._14': ['str', '._14', '._14']
+'.inf': ['str', '.inf', '.inf']
+'.nan': ['str', '.nan', '.nan']
+'0': ['int', '0', '0']
+'0.0': ['float', '0.0', '0.0']
+'0.3e3': ['float', '300.0', '300.0']
+'00': ['str', '00', '00']
+'001.23': ['str', '001.23', '001.23']
+'0011': ['str', '0011', '0011']
+'010': ['str', '010', '010']
+'02_0': ['str', '02_0', '02_0']
+'07': ['str', '07', '07']
+'08': ['str', '08', '08']
+'0b0': ['str', '0b0', '0b0']
+'0b100_101': ['str', '0b100_101', '0b100_101']
+'0o0': ['str', '0o0', '0o0']
+'0o10': ['str', '0o10', '0o10']
+'0o7': ['str', '0o7', '0o7']
+'0x0': ['str', '0x0', '0x0']
+'0x10': ['str', '0x10', '0x10']
+'0x2_0': ['str', '0x2_0', '0x2_0']
+'0x42': ['str', '0x42', '0x42']
+'0xa': ['str', '0xa', '0xa']
+'100_000': ['str', '100_000', '100_000']
+'190:20:30': ['str', '190:20:30', '190:20:30']
+'190:20:30.15': ['str', '190:20:30.15', '190:20:30.15']
+'23': ['int', '23', '23']
+'3.': ['float', '3.0', '3.0']
+'3.14': ['float', '3.14', '3.14']
+'3.3e+3': ['float', '3300', '3300.0']
+'3e3': ['float', '3000', '3000.0']
+'85.230_15e+03': ['str', '85.230_15e+03', '85.230_15e+03']
+'85_230.15': ['str', '85_230.15', '85_230.15']
+'FALSE': ['str', 'FALSE', 'FALSE']
+'False': ['str', 'False', 'False']
+'N': ['str', 'N', "N"]
+'NO': ['str', 'NO', "NO"]
+'NULL': ['str', 'NULL', 'NULL']
+'Null': ['str', 'Null', 'Null']
+'OFF': ['str', 'OFF', "OFF"]
+'ON': ['str', 'ON', "ON"]
+'Off': ['str', 'Off', "Off"]
+'On': ['str', 'On', "On"]
+'TRUE': ['str', 'TRUE', 'TRUE']
+'True': ['str', 'True', 'True']
+'Y': ['str', 'Y', "Y"]
+'YES': ['str', 'YES', "YES"]
+'Yes': ['str', 'Yes', "Yes"]
+'_._': ['str', '_._', '_._']
+'false': ['bool', 'false()', 'false']
+'n': ['str', 'n', "n"]
+'no': ['str', 'no', "no"]
+'null': ['null', 'null()', "null"]
+'off': ['str', 'off', "off"]
+'on': ['str', 'on', "on"]
+'true': ['bool', 'true()', 'true']
+'y': ['str', 'y', "y"]
+'yes': ['str', 'yes', "yes"]
+'~': ['str', '~', '~']
diff --git a/tests/data/json.schema-skip b/tests/data/json.schema-skip
new file mode 100644
index 00000000..d2fe12e4
--- /dev/null
+++ b/tests/data/json.schema-skip
@@ -0,0 +1,6 @@
+load: {
+  }
+dump: {
+    '#empty': 1,
+    '!!str #empty': 1,
+  }
diff --git a/tests/data/yaml11.schema b/tests/data/yaml11.schema
new file mode 100644
index 00000000..e2791aa7
--- /dev/null
+++ b/tests/data/yaml11.schema
@@ -0,0 +1,264 @@
+# https://github.com/perlpunk/yaml-test-schema/blob/master/data/schema-yaml11.yaml
+---
+'!!bool FALSE': ['bool', 'false()', 'false']
+'!!bool False': ['bool', 'false()', 'false']
+'!!bool N': ['bool', 'false()', "false"]
+'!!bool NO': ['bool', 'false()', "false"]
+'!!bool No': ['bool', 'false()', "false"]
+'!!bool OFF': ['bool', 'false()', "false"]
+'!!bool ON': ['bool', 'true()', "true"]
+'!!bool Off': ['bool', 'false()', "false"]
+'!!bool On': ['bool', 'true()', "true"]
+'!!bool TRUE': ['bool', 'true()', 'true']
+'!!bool True': ['bool', 'true()', 'true']
+'!!bool Y': ['bool', 'true()', "true"]
+'!!bool YES': ['bool', 'true()', "true"]
+'!!bool Yes': ['bool', 'true()', "true"]
+'!!bool false': ['bool', 'false()', 'false']
+'!!bool n': ['bool', 'false()', "false"]
+'!!bool no': ['bool', 'false()', "false"]
+'!!bool off': ['bool', 'false()', "false"]
+'!!bool on': ['bool', 'true()', "true"]
+'!!bool true': ['bool', 'true()', 'true']
+'!!bool y': ['bool', 'true()', "true"]
+'!!bool yes': ['bool', 'true()', "true"]
+'!!float +.INF': ['inf', 'inf()', '.inf']
+'!!float +.Inf': ['inf', 'inf()', '.inf']
+'!!float +.inf': ['inf', 'inf()', '.inf']
+'!!float +0.3e+3': ['float', '300.0', '300.0']
+'!!float -.INF': ['inf', 'inf-neg()', '-.inf']
+'!!float -.Inf': ['inf', 'inf-neg()', '-.inf']
+'!!float -.inf': ['inf', 'inf-neg()', '-.inf']
+'!!float -3.14': ['float', '-3.14', '-3.14']
+'!!float .0': ['float', '0.0', '0.0']
+'!!float .14': ['float', '0.14', '0.14']
+'!!float .1_4': ['float', '0.14', '0.14']
+'!!float .3E-1': ['float', '0.03', '0.03']
+'!!float .3e+3': ['float', '300.0', '300.0']
+'!!float .INF': ['inf', 'inf()', '.inf']
+'!!float .Inf': ['inf', 'inf()', '.inf']
+'!!float .NAN': ['nan', 'nan()', '.nan']
+'!!float .NaN': ['nan', 'nan()', '.nan']
+'!!float .inf': ['inf', 'inf()', '.inf']
+'!!float .nan': ['nan', 'nan()', '.nan']
+'!!float 0.0': ['float', '0.0', '0.0']
+'!!float 001.23': ['float', '1.23', '1.23']
+'!!float 190:20:30.15': ['float', '685230.15', '685230.15']
+'!!float 3.': ['float', '3.0', '3.0']
+'!!float 3.14': ['float', '3.14', '3.14']
+'!!float 3.3e+3': ['float', '3300.0', '3300.0']
+'!!float 85.230_15e+03': ['float', '85230.15', '85230.15']
+'!!float 85_230.15': ['float', '85230.15', '85230.15']
+'!!int +0': ['int', '0', '0']
+'!!int +0100_200': ['int', '32896', '32896']
+'!!int +0b100': ['int', '4', '4']
+'!!int +190:20:30': ['int', '685230', '685230']
+'!!int +23': ['int', '23', '23']
+'!!int -0': ['int', '0', '0']
+'!!int -0100_200': ['int', '-32896', '-32896']
+'!!int -0b101': ['int', '-5', '-5']
+'!!int -0x30': ['int', '-48', '-48']
+'!!int -190:20:30': ['int', '-685230', '-685230']
+'!!int -23': ['int', '-23', '-23']
+'!!int 0': ['int', '0', '0']
+'!!int 00': ['int', '0', '0']
+'!!int 0011': ['int', '9', '9']
+'!!int 010': ['int', '8', '8']
+'!!int 02_0': ['int', '16', '16']
+'!!int 07': ['int', '7', '7']
+'!!int 0b0': ['int', '0', '0']
+'!!int 0b100_101': ['int', '37', '37']
+'!!int 0x0': ['int', '0', '0']
+'!!int 0x10': ['int', '16', '16']
+'!!int 0x2_0': ['int', '32', '32']
+'!!int 0x42': ['int', '66', '66']
+'!!int 0xa': ['int', '10', '10']
+'!!int 100_000': ['int', '100000', '100000']
+'!!int 190:20:30': ['int', '685230', '685230']
+'!!int 23': ['int', '23', '23']
+'!!null #empty': ['null', 'null()', "null"]
+'!!null NULL': ['null', 'null()', "null"]
+'!!null Null': ['null', 'null()', "null"]
+'!!null null': ['null', 'null()', 'null']
+'!!null ~': ['null', 'null()', 'null']
+'!!str #empty': ['str', '', "''"]
+'!!str +.INF': ['str', '+.INF', "'+.INF'"]
+'!!str +.Inf': ['str', '+.Inf', "'+.Inf'"]
+'!!str +.inf': ['str', '+.inf', "'+.inf'"]
+'!!str +0': ['str', '+0', "'+0'"]
+'!!str +0.3e+3': ['str', '+0.3e+3', "'+0.3e+3'"]
+'!!str +0.3e3': ['str', '+0.3e3', "+0.3e3"]
+'!!str +0100_200': ['str', '+0100_200', "'+0100_200'"]
+'!!str +0b100': ['str', '+0b100', "'+0b100'"]
+'!!str +190:20:30': ['str', '+190:20:30', "'+190:20:30'"]
+'!!str +23': ['str', '+23', "'+23'"]
+'!!str -.INF': ['str', '-.INF', "'-.INF'"]
+'!!str -.Inf': ['str', '-.Inf', "'-.Inf'"]
+'!!str -.inf': ['str', '-.inf', "'-.inf'"]
+'!!str -0': ['str', '-0', "'-0'"]
+'!!str -0100_200': ['str', '-0100_200', "'-0100_200'"]
+'!!str -0b101': ['str', '-0b101', "'-0b101'"]
+'!!str -0x30': ['str', '-0x30', "'-0x30'"]
+'!!str -190:20:30': ['str', '-190:20:30', "'-190:20:30'"]
+'!!str -23': ['str', '-23', "'-23'"]
+'!!str -3.14': ['str', '-3.14', "'-3.14'"]
+'!!str .': ['str', '.', '.']
+'!!str .0': ['str', '.0', "'.0'"]
+'!!str .14': ['str', '.14', "'.14'"]
+'!!str .1_4': ['str', '.1_4', "'.1_4'"]
+'!!str .3E-1': ['str', '.3E-1', "'.3E-1'"]
+'!!str .3e+3': ['str', '.3e+3', "'.3e+3'"]
+'!!str .3e3': ['str', '.3e3', ".3e3"]
+'!!str .INF': ['str', '.INF', "'.INF'"]
+'!!str .Inf': ['str', '.Inf', "'.Inf'"]
+'!!str .NAN': ['str', '.NAN', "'.NAN'"]
+'!!str .NaN': ['str', '.NaN', "'.NaN'"]
+'!!str ._': ['str', '._', '._']
+'!!str ._14': ['str', '._14', '._14']
+'!!str .inf': ['str', '.inf', "'.inf'"]
+'!!str .nan': ['str', '.nan', "'.nan'"]
+'!!str 0': ['str', '0', "'0'"]
+'!!str 0.0': ['str', '0.0', "'0.0'"]
+'!!str 0.3e3': ['str', '0.3e3', "0.3e3"]
+'!!str 00': ['str', '00', "'00'"]
+'!!str 001.23': ['str', '001.23', "'001.23'"]
+'!!str 0011': ['str', '0011', "'0011'"]
+'!!str 010': ['str', '010', "'010'"]
+'!!str 02_0': ['str', '02_0', "'02_0'"]
+'!!str 07': ['str', '07', "'07'"]
+'!!str 0b0': ['str', '0b0', "'0b0'"]
+'!!str 0b100_101': ['str', '0b100_101', "'0b100_101'"]
+'!!str 0o0': ['str', '0o0', "0o0"]
+'!!str 0o10': ['str', '0o10', "0o10"]
+'!!str 0o7': ['str', '0o7', "0o7"]
+'!!str 0x0': ['str', '0x0', "'0x0'"]
+'!!str 0x2_0': ['str', '0x2_0', "'0x2_0'"]
+'!!str 0xa': ['str', '0xa', "'0xa'"]
+'!!str 100_000': ['str', '100_000', "'100_000'"]
+'!!str 190:20:30': ['str', '190:20:30', "'190:20:30'"]
+'!!str 190:20:30.15': ['str', '190:20:30.15', "'190:20:30.15'"]
+'!!str 23': ['str', '23', "'23'"]
+'!!str 3.': ['str', '3.', "'3.'"]
+'!!str 3.14': ['str', '3.14', "'3.14'"]
+'!!str 3.3e+3': ['str', '3.3e+3', "'3.3e+3'"]
+'!!str 85.230_15e+03': ['str', '85.230_15e+03', "'85.230_15e+03'"]
+'!!str 85_230.15': ['str', '85_230.15', "'85_230.15'"]
+'!!str FALSE': ['str', 'FALSE', "'FALSE'"]
+'!!str False': ['str', 'False', "'False'"]
+'!!str N': ['str', 'N', "'N'"]
+'!!str NO': ['str', 'NO', "'NO'"]
+'!!str NULL': ['str', 'NULL', "'NULL'"]
+'!!str Null': ['str', 'Null', "'Null'"]
+'!!str OFF': ['str', 'OFF', "'OFF'"]
+'!!str ON': ['str', 'ON', "'ON'"]
+'!!str Off': ['str', 'Off', "'Off'"]
+'!!str On': ['str', 'On', "'On'"]
+'!!str TRUE': ['str', 'TRUE', "'TRUE'"]
+'!!str True': ['str', 'True', "'True'"]
+'!!str Y': ['str', 'Y', "'Y'"]
+'!!str YES': ['str', 'YES', "'YES'"]
+'!!str Yes': ['str', 'Yes', "'Yes'"]
+'!!str _._': ['str', '_._', '_._']
+'!!str false': ['str', 'false', "'false'"]
+'!!str n': ['str', 'n', "'n'"]
+'!!str no': ['str', 'no', "'no'"]
+'!!str null': ['str', 'null', "'null'"]
+'!!str off': ['str', 'off', "'off'"]
+'!!str on': ['str', 'on', "'on'"]
+'!!str true': ['str', 'true', "'true'"]
+'!!str y': ['str', 'y', "'y'"]
+'!!str yes': ['str', 'yes', "'yes'"]
+'!!str ~': ['str', '~', "'~'"]
+'#empty': ['null', 'null()', "null"]
+'+.INF': ['inf', 'inf()', '.inf']
+'+.Inf': ['inf', 'inf()', '.inf']
+'+.inf': ['inf', 'inf()', '.inf']
+'+0': ['int', '0', '0']
+'+0.3e+3': ['float', '300.0', '300.0']
+'+0.3e3': ['str', '+0.3e3', '+0.3e3']
+'+0100_200': ['int', '32896', '32896']
+'+0b100': ['int', '4', '4']
+'+190:20:30': ['int', '685230', '685230']
+'+23': ['int', '23', '23']
+'+3.14': ['float', '3.14', '3.14']
+'-.INF': ['inf', 'inf-neg()', '-.inf']
+'-.Inf': ['inf', 'inf-neg()', '-.inf']
+'-.inf': ['inf', 'inf-neg()', '-.inf']
+'-0': ['int', '0', '0']
+'-0100_200': ['int', '-32896', '-32896']
+'-0b101': ['int', '-5', '-5']
+'-0x30': ['int', '-48', '-48']
+'-190:20:30': ['int', '-685230', '-685230']
+'-23': ['int', '-23', '-23']
+'-3.14': ['float', '-3.14', '-3.14']
+'.': ['str', '.', '.']
+'.0': ['float', '0.0', '0.0']
+'.14': ['float', '0.14', '0.14']
+'.1_4': ['float', '0.14', '0.14']
+'.3E-1': ['float', '0.03', '0.03']
+'.3e+3': ['float', '300.0', '300.0']
+'.3e3': ['str', '.3e3', '.3e3']
+'.INF': ['inf', 'inf()', '.inf']
+'.Inf': ['inf', 'inf()', '.inf']
+'.NAN': ['nan', 'nan()', '.nan']
+'.NaN': ['nan', 'nan()', '.nan']
+'._': ['str', '._', '._']
+'._14': ['str', '._14', '._14']
+'.inf': ['inf', 'inf()', '.inf']
+'.nan': ['nan', 'nan()', '.nan']
+'0': ['int', '0', '0']
+'0.0': ['float', '0.0', '0.0']
+'0.3e3': ['str', '0.3e3', '0.3e3']
+'00': ['int', '0', '0']
+'001.23': ['float', '1.23', '1.23']
+'0011': ['int', '9', '9']
+'010': ['int', '8', '8']
+'02_0': ['int', '16', '16']
+'07': ['int', '7', '7']
+'08': ['str', '08', '08']
+'0b0': ['int', '0', '0']
+'0b100_101': ['int', '37', '37']
+'0o0': ['str', '0o0', '0o0']
+'0o10': ['str', '0o10', '0o10']
+'0o7': ['str', '0o7', '0o7']
+'0x0': ['int', '0', '0']
+'0x10': ['int', '16', '16']
+'0x2_0': ['int', '32', '32']
+'0x42': ['int', '66', '66']
+'0xa': ['int', '10', '10']
+'100_000': ['int', '100000', '100000']
+'190:20:30': ['int', '685230', '685230']
+'190:20:30.15': ['float', '685230.15', '685230.15']
+'23': ['int', '23', '23']
+'3.': ['float', '3.0', '3.0']
+'3.14': ['float', '3.14', '3.14']
+'3.3e+3': ['float', '3300', '3300.0']
+'3e3': ['str', '3e3', '3e3']
+'85.230_15e+03': ['float', '85230.15', '85230.15']
+'85_230.15': ['float', '85230.15', '85230.15']
+'FALSE': ['bool', 'false()', 'false']
+'False': ['bool', 'false()', 'false']
+'N': ['bool', 'false()', "false"]
+'NO': ['bool', 'false()', "false"]
+'NULL': ['null', 'null()', "null"]
+'Null': ['null', 'null()', "null"]
+'OFF': ['bool', 'false()', "false"]
+'ON': ['bool', 'true()', "true"]
+'Off': ['bool', 'false()', "false"]
+'On': ['bool', 'true()', "true"]
+'TRUE': ['bool', 'true()', 'true']
+'True': ['bool', 'true()', 'true']
+'Y': ['bool', 'true()', "true"]
+'YES': ['bool', 'true()', "true"]
+'Yes': ['bool', 'true()', "true"]
+'_._': ['str', '_._', '_._']
+'false': ['bool', 'false()', 'false']
+'n': ['bool', 'false()', "false"]
+'no': ['bool', 'false()', "false"]
+'null': ['null', 'null()', "null"]
+'off': ['bool', 'false()', "false"]
+'on': ['bool', 'true()', "true"]
+'true': ['bool', 'true()', 'true']
+'y': ['bool', 'true()', "true"]
+'yes': ['bool', 'true()', "true"]
+'~': ['null', 'null()', "null"]
diff --git a/tests/data/yaml11.schema-skip b/tests/data/yaml11.schema-skip
new file mode 100644
index 00000000..4fe0f0bf
--- /dev/null
+++ b/tests/data/yaml11.schema-skip
@@ -0,0 +1,9 @@
+load: {
+  'Y': 1, 'y': 1, 'N': 1, 'n': 1,
+  '!!bool Y': 1, '!!bool N': 1, '!!bool n': 1, '!!bool y': 1,
+  '._',   '!!str ._',
+  '._14', '!!str ._14'
+  }
+dump: {
+  '!!str N': 1, '!!str Y': 1, '!!str n': 1, '!!str y': 1,
+  }
diff --git a/tests/lib/test_constructor.py b/tests/lib/test_constructor.py
index f9a50770..28987d29 100644
--- a/tests/lib/test_constructor.py
+++ b/tests/lib/test_constructor.py
@@ -5,6 +5,9 @@
 import datetime
 import yaml.tokens
 
+# Import any packages here that need to be referenced in .code files.
+import signal
+
 def execute(code):
     global value
     exec(code)
diff --git a/tests/lib/test_schema.py b/tests/lib/test_schema.py
new file mode 100644
index 00000000..7bc84b7f
--- /dev/null
+++ b/tests/lib/test_schema.py
@@ -0,0 +1,188 @@
+import yaml
+import os
+import sys
+import pprint
+import math
+
+def check_bool(value, expected):
+    if expected == 'false()' and value is False:
+        return 1
+    if expected == 'true()' and value is True:
+        return 1
+    print(value)
+    print(expected)
+    return 0
+
+def check_int(value, expected):
+    if (int(expected) == value):
+        return 1
+    print(value)
+    print(expected)
+    return 0
+
+def check_float(value, expected):
+    if expected == 'inf()':
+        if value == math.inf:
+            return 1
+    elif expected == 'inf-neg()':
+        if value == -math.inf:
+            return 1
+    elif expected == 'nan()':
+        if math.isnan(value):
+            return 1
+    elif (float(expected) == value):
+        return 1
+    else:
+        print(value)
+        print(expected)
+        return 0
+
+def check_str(value, expected):
+    if value == expected:
+        return 1
+    print(value)
+    print(expected)
+    return 0
+
+
+def _fail(input, test):
+    print("Input: >>" + input + "<<")
+    print(test)
+
+class MyCoreLoader(yaml.BaseLoader): pass
+class MyJSONLoader(yaml.BaseLoader): pass
+class MyCoreDumper(yaml.CommonDumper): pass
+class MyJSONDumper(yaml.CommonDumper): pass
+
+MyCoreLoader.init_tags('core')
+MyJSONLoader.init_tags('json')
+
+MyCoreDumper.init_tags('core')
+MyJSONDumper.init_tags('json')
+
+# The tests/data/yaml11.schema file is copied from
+# https://github.com/perlpunk/yaml-test-schema/blob/master/data/schema-yaml11.yaml
+def test_implicit_resolver(data_filename, skip_filename, verbose=False):
+    types = {
+        'str':   [str,   check_str],
+        'int':   [int,   check_int],
+        'float': [float, check_float],
+        'inf':   [float, check_float],
+        'nan':   [float, check_float],
+        'bool':  [bool,  check_bool],
+    }
+    loaders = {
+        'yaml11': yaml.SafeLoader,
+        'core': MyCoreLoader,
+        'json': MyJSONLoader,
+    }
+    dumpers = {
+        'yaml11': yaml.SafeDumper,
+        'core': MyCoreDumper,
+        'json': MyJSONDumper,
+    }
+    loadername = os.path.splitext(os.path.basename(data_filename))[0]
+    print('==================')
+    print(loadername)
+    with open(skip_filename, 'rb') as file:
+        skipdata = yaml.load(file, Loader=yaml.SafeLoader)
+    skip_load = skipdata['load']
+    skip_dump = skipdata['dump']
+    if verbose:
+        print(skip_load)
+    with open(data_filename, 'rb') as file:
+        tests = yaml.load(file, Loader=yaml.SafeLoader)
+
+    i = 0
+    fail = 0
+    for i, (input, test) in enumerate(sorted(tests.items())):
+        if verbose:
+            print('-------------------- ' + str(i))
+
+        # Skip known loader bugs
+        if input in skip_load:
+            continue
+
+        exp_type = test[0]
+        data     = test[1]
+        exp_dump = test[2]
+
+        # Test loading
+        try:
+            doc_input = """---\n""" + input
+            loaded = yaml.load(doc_input, Loader=loaders[loadername])
+        except:
+            print("Error:", sys.exc_info()[0], '(', sys.exc_info()[1], ')')
+            fail+=1
+            _fail(input, test)
+            continue
+
+        if verbose:
+            print(input)
+            print(test)
+            print(loaded)
+            print(type(loaded))
+
+        if exp_type == 'null':
+            if loaded is None:
+                pass
+            else:
+                fail+=1
+                _fail(input, test)
+        else:
+            t = types[exp_type][0]
+            code = types[exp_type][1]
+
+            if isinstance(loaded, t):
+                if code(loaded, data):
+                    pass
+                else:
+                    fail+=1
+                    print("Expected data: >>" + str(data) + "<< Got: >>" + str(loaded) + "<<")
+                    _fail(input, test)
+            else:
+                fail+=1
+                print("Expected type: >>" + exp_type + "<< Got: >>" + str(loaded) + "<<")
+                _fail(input, test)
+
+        # Skip known dumper bugs
+        if input in skip_dump:
+            continue
+
+        dump = yaml.dump(loaded, explicit_end=False, Dumper=dumpers[loadername])
+        # strip trailing newlines and footers
+        if (dump == '...\n'):
+            dump = ''
+        if dump.endswith('\n...\n'):
+            dump = dump[:-5]
+        if dump.endswith('\n'):
+            dump = dump[:-1]
+        if dump == exp_dump:
+            pass
+        else:
+            print("Compare: >>" + dump + "<< >>" + exp_dump + "<<")
+            print(skip_dump)
+            print(input)
+            print(test)
+            print(loaded)
+            print(type(loaded))
+            fail+=1
+            _fail(input, test)
+
+#        if i >= 80:
+#            break
+
+    if fail > 0:
+        print("Failed " + str(fail) + " / " + str(i) + " tests")
+        assert(False)
+    else:
+        print("Passed " + str(i) + " tests")
+    print("Skipped " + str(len(skip_load)) + " load tests")
+    print("Skipped " + str(len(skip_dump)) + " dump tests")
+
+test_implicit_resolver.unittest = ['.schema', '.schema-skip']
+
+if __name__ == '__main__':
+    import test_appliance
+    test_appliance.run(globals())
+
diff --git a/tests/lib/test_yaml.py b/tests/lib/test_yaml.py
index 352cd8d1..7b3d8f9d 100644
--- a/tests/lib/test_yaml.py
+++ b/tests/lib/test_yaml.py
@@ -14,6 +14,8 @@
 from test_sort_keys import *
 from test_multi_constructor import *
 
+from test_schema import *
+
 if __name__ == '__main__':
     import test_appliance
     test_appliance.run(globals())
diff --git a/yaml/_yaml.pyx b/yaml/_yaml.pyx
index ff4efe80..47dedab5 100644
--- a/yaml/_yaml.pyx
+++ b/yaml/_yaml.pyx
@@ -1,6 +1,14 @@
 
 import yaml
 
+# FIXME: change all the below stuff to from X import Y to avoid this
+# import submodules explicitly since we're getting loaded earlier
+import yaml.emitter
+import yaml.parser
+import yaml.reader
+import yaml.scanner
+import yaml.serializer
+
 def get_version_string():
     cdef char *value
     value = yaml_get_version_string()