From 23820d3927cd7eecd39acf3fcb7feaecb5afedb9 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 24 Mar 2020 10:49:27 -0400
Subject: [PATCH 01/14] Add resource reader as proposed by Gregory in
 https://gitlab.com/python-devs/importlib_resources/-/issues/90#note_307473902

---
 importlib_resources/abc.py | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 4371a77c..e4f1eb3a 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -112,6 +112,34 @@ def name(self) -> str:
         """
 
 
+class ResourceReader:
+    # Holds the string name of the virtual Python package this is a resource loader for.
+    # For filesystems, this is effectively a reader for a directory at `fullname.replace('.', '/')`
+    fullname = None
+
+    def child_readers(self) -> [ResourceReader]
+        """Obtain an iterable of ResourceReader for available child virtual packages of this one.
+
+        On filesystems, this essentially returns instances corresponding to immediate child directories.
+        """
+
+    def resources(self) -> [str]
+        """Obtain available named resources for this virtual package.
+
+        On filesystems, this essentially returns files in the current directory.
+        TODO consider returning a special type that exposes an `open()`, etc.
+        """"
+
+    def open_binary(self, resource) -> File
+        """Obtain a File-like for a named resource.
+
+        On filesystems, this attempts to open os.path.join(self, resource).
+
+        Attempting to open a non-resource entity (such as a subdirectory) or a missing
+        resource raises NotAResourceError.
+        """
+
+
 class TraversableResources(ResourceReader):
     @abc.abstractmethod
     def files(self):

From 0355a88c68aaf44c855d1e13beea813cb0b2aee7 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 24 Mar 2020 10:50:42 -0400
Subject: [PATCH 02/14] Fix syntax

---
 importlib_resources/abc.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index e4f1eb3a..164e0195 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -112,25 +112,25 @@ def name(self) -> str:
         """
 
 
-class ResourceReader:
+class SimpleReader:
     # Holds the string name of the virtual Python package this is a resource loader for.
     # For filesystems, this is effectively a reader for a directory at `fullname.replace('.', '/')`
     fullname = None
 
-    def child_readers(self) -> [ResourceReader]
+    def child_readers(self) -> ['SimpleReader']:
         """Obtain an iterable of ResourceReader for available child virtual packages of this one.
 
         On filesystems, this essentially returns instances corresponding to immediate child directories.
         """
 
-    def resources(self) -> [str]
+    def resources(self) -> [str]:
         """Obtain available named resources for this virtual package.
 
         On filesystems, this essentially returns files in the current directory.
         TODO consider returning a special type that exposes an `open()`, etc.
-        """"
+        """
 
-    def open_binary(self, resource) -> File
+    def open_binary(self, resource) -> BinaryIO:
         """Obtain a File-like for a named resource.
 
         On filesystems, this attempts to open os.path.join(self, resource).

From 93b1c6d57cca3fe587a574ad09c35530c1e2c691 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 24 Mar 2020 10:56:01 -0400
Subject: [PATCH 03/14] Convert to an ABC

---
 importlib_resources/abc.py | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 164e0195..39db2461 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -112,31 +112,31 @@ def name(self) -> str:
         """
 
 
-class SimpleReader:
-    # Holds the string name of the virtual Python package this is a resource loader for.
-    # For filesystems, this is effectively a reader for a directory at `fullname.replace('.', '/')`
-    fullname = None
+class SimpleReader(ABC):
 
-    def child_readers(self) -> ['SimpleReader']:
-        """Obtain an iterable of ResourceReader for available child virtual packages of this one.
+    @abc.abstractproperty
+    def package(self):
+        """
+        The name of the package for which this reader loads resources.
+        """
 
-        On filesystems, this essentially returns instances corresponding to immediate child directories.
+    @abc.abstractmethod
+    def child_readers(self) -> ['SimpleReader']:
+        """
+        Obtain an iterable of ResourceReader for available
+        child virtual packages of this one.
         """
 
+    @abc.abstractmethod
     def resources(self) -> [str]:
-        """Obtain available named resources for this virtual package.
-
-        On filesystems, this essentially returns files in the current directory.
-        TODO consider returning a special type that exposes an `open()`, etc.
+        """
+        Obtain available named resources for this virtual package.
         """
 
+    @abc.abstractmethod
     def open_binary(self, resource) -> BinaryIO:
-        """Obtain a File-like for a named resource.
-
-        On filesystems, this attempts to open os.path.join(self, resource).
-
-        Attempting to open a non-resource entity (such as a subdirectory) or a missing
-        resource raises NotAResourceError.
+        """
+        Obtain a File-like for a named resource.
         """
 
 

From 2d86bc3b710ebc699c1901d39105100df068883f Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Mon, 18 Jan 2021 18:58:11 -0500
Subject: [PATCH 04/14] Implement TraversableReader, based on SimpleReader

---
 importlib_resources/abc.py | 59 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 39db2461..2473c749 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -1,4 +1,6 @@
 import abc
+import io
+import itertools
 from typing import BinaryIO, Iterable, Text
 
 from ._compat import runtime_checkable, Protocol
@@ -112,7 +114,7 @@ def name(self) -> str:
         """
 
 
-class SimpleReader(ABC):
+class SimpleReader(abc.ABC):
 
     @abc.abstractproperty
     def package(self):
@@ -139,6 +141,10 @@ def open_binary(self, resource) -> BinaryIO:
         Obtain a File-like for a named resource.
         """
 
+    @property
+    def name(self):
+        return self.package.split('.')[-1]
+
 
 class TraversableResources(ResourceReader):
     @abc.abstractmethod
@@ -156,3 +162,54 @@ def is_resource(self, path):
 
     def contents(self):
         return (item.name for item in self.files().iterdir())
+
+
+class ResourceHandle(Traversable):
+    def __init__(self, reader, name):
+        self.reader = reader
+        self.name = name
+
+    def is_file(self):
+        return True
+
+    def is_dir(self):
+        return False
+
+    def open(self, mode='r', *args, **kwargs):
+        stream = self.reader.open_binary(self.name)
+        if 'b' not in mode:
+            stream = io.TextIOWrapper(*args, **kwargs)
+        return stream
+
+
+class ResourceContainer(Traversable):
+    def __init__(self, reader: SimpleReader):
+        self.reader = reader
+
+    def is_dir(self):
+        return True
+
+    def is_file(self):
+        return False
+
+    def iterdir(self):
+        files = (
+            ResourceHandle(self, name)
+            for name in self.resources
+            )
+        dirs = map(ResourceContainer, self.child_readers())
+        return itertools.chain(files, dirs)
+
+    def open(self, *args, **kwargs):
+        raise IsADirectoryError()
+
+    def joinpath(self, name):
+        return next(
+            traversable
+            for traversable in self.iterdir()
+            if traversable.name == name)
+
+
+class TraversableReader(TraversableResources, SimpleReader):
+    def files(self):
+        return ResourceContainer(self)

From 0de43b9721dd9cba3a3cd8e66f4acee90d8ae5b4 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 24 Mar 2020 11:22:55 -0400
Subject: [PATCH 05/14] Make read_bytes and read_text and __truediv__ concrete
 implementations based on other abstract methods.

---
 importlib_resources/abc.py | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 2473c749..7ccadee5 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -61,17 +61,19 @@ def iterdir(self):
         Yield Traversable objects in self
         """
 
-    @abc.abstractmethod
     def read_bytes(self):
         """
         Read contents of self as bytes
         """
+        with self.open('rb') as strm:
+            return strm.read()
 
-    @abc.abstractmethod
     def read_text(self, encoding=None):
         """
-        Read contents of self as bytes
+        Read contents of self as text
         """
+        with self.open(encoding=encoding) as strm:
+            return strm.read()
 
     @abc.abstractmethod
     def is_dir(self):
@@ -91,11 +93,11 @@ def joinpath(self, child):
         Return Traversable child in self
         """
 
-    @abc.abstractmethod
     def __truediv__(self, child):
         """
         Return Traversable child in self
         """
+        return self.joinpath(child)
 
     @abc.abstractmethod
     def open(self, mode='r', *args, **kwargs):

From 72feafeb4b90f6ba111eaebef9dacce39180f489 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Mon, 18 Jan 2021 18:59:03 -0500
Subject: [PATCH 06/14] Fix typing syntax

---
 importlib_resources/abc.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 7ccadee5..cc398dfc 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -1,7 +1,7 @@
 import abc
 import io
 import itertools
-from typing import BinaryIO, Iterable, Text
+from typing import BinaryIO, Iterable, Text, List
 
 from ._compat import runtime_checkable, Protocol
 
@@ -125,14 +125,14 @@ def package(self):
         """
 
     @abc.abstractmethod
-    def child_readers(self) -> ['SimpleReader']:
+    def child_readers(self) -> List['SimpleReader']:
         """
         Obtain an iterable of ResourceReader for available
         child virtual packages of this one.
         """
 
     @abc.abstractmethod
-    def resources(self) -> [str]:
+    def resources(self) -> List[str]:
         """
         Obtain available named resources for this virtual package.
         """

From b7ee6fbc41e7737cebfa690b66c39f22a370dc9d Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Tue, 24 Mar 2020 11:34:59 -0400
Subject: [PATCH 07/14] Implement abstract method on ResourceHandle and add
 docstrings

---
 importlib_resources/abc.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index cc398dfc..47541b21 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -167,6 +167,10 @@ def contents(self):
 
 
 class ResourceHandle(Traversable):
+    """
+    Handle to a named resource in a ResourceReader.
+    """
+
     def __init__(self, reader, name):
         self.reader = reader
         self.name = name
@@ -183,8 +187,15 @@ def open(self, mode='r', *args, **kwargs):
             stream = io.TextIOWrapper(*args, **kwargs)
         return stream
 
+    def joinpath(self, name):
+        raise RuntimeError("Cannot traverse into a resource")
+
 
 class ResourceContainer(Traversable):
+    """
+    Traversable container for a package's resources via its reader.
+    """
+
     def __init__(self, reader: SimpleReader):
         self.reader = reader
 

From 35297321ab56c9b411bcb38d364ec5b4a9f4c72e Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sat, 11 Apr 2020 11:41:26 -0400
Subject: [PATCH 08/14] Update wording on SimpleReader.child_readers. Rename
 'child_readers' to simply 'children'.

---
 importlib_resources/abc.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 47541b21..23a7b590 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -125,10 +125,10 @@ def package(self):
         """
 
     @abc.abstractmethod
-    def child_readers(self) -> List['SimpleReader']:
+    def children(self) -> List['SimpleReader']:
         """
-        Obtain an iterable of ResourceReader for available
-        child virtual packages of this one.
+        Obtain an iterable of SimpleReader for available
+        child containers (e.g. directories).
         """
 
     @abc.abstractmethod
@@ -210,7 +210,7 @@ def iterdir(self):
             ResourceHandle(self, name)
             for name in self.resources
             )
-        dirs = map(ResourceContainer, self.child_readers())
+        dirs = map(ResourceContainer, self.children())
         return itertools.chain(files, dirs)
 
     def open(self, *args, **kwargs):

From 27e9d7c70706c84f0ea019da3a71fe0b893e8b87 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sat, 11 Apr 2020 15:08:37 -0400
Subject: [PATCH 09/14] Add compatibility for Python 2.7

---
 importlib_resources/abc.py | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 23a7b590..af3277e0 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -125,20 +125,23 @@ def package(self):
         """
 
     @abc.abstractmethod
-    def children(self) -> List['SimpleReader']:
+    def children(self):
+        # type: () -> List['SimpleReader']
         """
         Obtain an iterable of SimpleReader for available
         child containers (e.g. directories).
         """
 
     @abc.abstractmethod
-    def resources(self) -> List[str]:
+    def resources(self):
+        # type: () -> List[str]
         """
         Obtain available named resources for this virtual package.
         """
 
     @abc.abstractmethod
-    def open_binary(self, resource) -> BinaryIO:
+    def open_binary(self, resource):
+        # type: (str) -> BinaryIO
         """
         Obtain a File-like for a named resource.
         """
@@ -196,7 +199,8 @@ class ResourceContainer(Traversable):
     Traversable container for a package's resources via its reader.
     """
 
-    def __init__(self, reader: SimpleReader):
+    def __init__(self, reader):
+        # type: (SimpleReader) -> None
         self.reader = reader
 
     def is_dir(self):

From 04b02010cc58f7033588d12290f9576fba7c2ba1 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Thu, 16 Apr 2020 19:53:11 -0400
Subject: [PATCH 10/14] Add docstrings and type annotations. Fix references to
 parent and reader between ResourceHandle and ResourceContainer.

---
 importlib_resources/abc.py | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index af3277e0..0942f8ab 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -77,12 +77,14 @@ def read_text(self, encoding=None):
 
     @abc.abstractmethod
     def is_dir(self):
+        # type: () -> bool
         """
         Return True if self is a dir
         """
 
     @abc.abstractmethod
     def is_file(self):
+        # type: () -> bool
         """
         Return True if self is a file
         """
@@ -117,9 +119,14 @@ def name(self) -> str:
 
 
 class SimpleReader(abc.ABC):
+    """
+    The minimum, low-level interface required from a resource
+    provider.
+    """
 
     @abc.abstractproperty
     def package(self):
+        # type: () -> str
         """
         The name of the package for which this reader loads resources.
         """
@@ -152,6 +159,11 @@ def name(self):
 
 
 class TraversableResources(ResourceReader):
+    """
+    The required interface for providing traversable
+    resources.
+    """
+
     @abc.abstractmethod
     def files(self):
         """Return a Traversable object for the loaded package."""
@@ -174,8 +186,9 @@ class ResourceHandle(Traversable):
     Handle to a named resource in a ResourceReader.
     """
 
-    def __init__(self, reader, name):
-        self.reader = reader
+    def __init__(self, parent, name):
+        # type: (ResourceContainer, str) -> None
+        self.parent = parent
         self.name = name
 
     def is_file(self):
@@ -185,7 +198,7 @@ def is_dir(self):
         return False
 
     def open(self, mode='r', *args, **kwargs):
-        stream = self.reader.open_binary(self.name)
+        stream = self.parent.reader.open_binary(self.name)
         if 'b' not in mode:
             stream = io.TextIOWrapper(*args, **kwargs)
         return stream
@@ -212,9 +225,9 @@ def is_file(self):
     def iterdir(self):
         files = (
             ResourceHandle(self, name)
-            for name in self.resources
+            for name in self.reader.resources
             )
-        dirs = map(ResourceContainer, self.children())
+        dirs = map(ResourceContainer, self.reader.children())
         return itertools.chain(files, dirs)
 
     def open(self, *args, **kwargs):
@@ -228,5 +241,10 @@ def joinpath(self, name):
 
 
 class TraversableReader(TraversableResources, SimpleReader):
+    """
+    A TraversableResources based on SimpleReader. Resource providers
+    may derive from this class to provide the TraversableResources
+    interface by supplying the SimpleReader interface.
+    """
     def files(self):
         return ResourceContainer(self)

From 4f486494858d3d916c369a4e43fcc7c64f79b084 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Mon, 18 Jan 2021 19:02:30 -0500
Subject: [PATCH 11/14] =?UTF-8?q?=E2=9A=AB=20Fade=20to=20black.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 importlib_resources/abc.py | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 0942f8ab..40d61819 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -223,10 +223,7 @@ def is_file(self):
         return False
 
     def iterdir(self):
-        files = (
-            ResourceHandle(self, name)
-            for name in self.reader.resources
-            )
+        files = (ResourceHandle(self, name) for name in self.reader.resources)
         dirs = map(ResourceContainer, self.reader.children())
         return itertools.chain(files, dirs)
 
@@ -235,9 +232,8 @@ def open(self, *args, **kwargs):
 
     def joinpath(self, name):
         return next(
-            traversable
-            for traversable in self.iterdir()
-            if traversable.name == name)
+            traversable for traversable in self.iterdir() if traversable.name == name
+        )
 
 
 class TraversableReader(TraversableResources, SimpleReader):
@@ -246,5 +242,6 @@ class TraversableReader(TraversableResources, SimpleReader):
     may derive from this class to provide the TraversableResources
     interface by supplying the SimpleReader interface.
     """
+
     def files(self):
         return ResourceContainer(self)

From f60d050afc427ef85e5d77cd63317ededa035cee Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Mon, 18 Jan 2021 19:02:40 -0500
Subject: [PATCH 12/14] =?UTF-8?q?=F0=9F=A7=8E=E2=80=8D=E2=99=80=EF=B8=8F?=
 =?UTF-8?q?=20Genuflect=20to=20the=20types.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 importlib_resources/abc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 40d61819..205a7d91 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -189,7 +189,7 @@ class ResourceHandle(Traversable):
     def __init__(self, parent, name):
         # type: (ResourceContainer, str) -> None
         self.parent = parent
-        self.name = name
+        self.name = name  # type: ignore
 
     def is_file(self):
         return True

From fbd44f05abf991250513f9bfec7611fbf6f620cd Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Mon, 18 Jan 2021 19:21:23 -0500
Subject: [PATCH 13/14] Move interfaces for low-level readers to their own
 module.

---
 importlib_resources/abc.py    | 110 +-------------------------------
 importlib_resources/simple.py | 116 ++++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+), 109 deletions(-)
 create mode 100644 importlib_resources/simple.py

diff --git a/importlib_resources/abc.py b/importlib_resources/abc.py
index 1b2230f8..56dc8127 100644
--- a/importlib_resources/abc.py
+++ b/importlib_resources/abc.py
@@ -1,7 +1,5 @@
 import abc
-import io
-import itertools
-from typing import BinaryIO, Iterable, Text, List
+from typing import BinaryIO, Iterable, Text
 
 from ._compat import runtime_checkable, Protocol
 
@@ -116,46 +114,6 @@ def name(self) -> str:
         """
 
 
-class SimpleReader(abc.ABC):
-    """
-    The minimum, low-level interface required from a resource
-    provider.
-    """
-
-    @abc.abstractproperty
-    def package(self):
-        # type: () -> str
-        """
-        The name of the package for which this reader loads resources.
-        """
-
-    @abc.abstractmethod
-    def children(self):
-        # type: () -> List['SimpleReader']
-        """
-        Obtain an iterable of SimpleReader for available
-        child containers (e.g. directories).
-        """
-
-    @abc.abstractmethod
-    def resources(self):
-        # type: () -> List[str]
-        """
-        Obtain available named resources for this virtual package.
-        """
-
-    @abc.abstractmethod
-    def open_binary(self, resource):
-        # type: (str) -> BinaryIO
-        """
-        Obtain a File-like for a named resource.
-        """
-
-    @property
-    def name(self):
-        return self.package.split('.')[-1]
-
-
 class TraversableResources(ResourceReader):
     """
     The required interface for providing traversable
@@ -177,69 +135,3 @@ def is_resource(self, path):
 
     def contents(self):
         return (item.name for item in self.files().iterdir())
-
-
-class ResourceHandle(Traversable):
-    """
-    Handle to a named resource in a ResourceReader.
-    """
-
-    def __init__(self, parent, name):
-        # type: (ResourceContainer, str) -> None
-        self.parent = parent
-        self.name = name  # type: ignore
-
-    def is_file(self):
-        return True
-
-    def is_dir(self):
-        return False
-
-    def open(self, mode='r', *args, **kwargs):
-        stream = self.parent.reader.open_binary(self.name)
-        if 'b' not in mode:
-            stream = io.TextIOWrapper(*args, **kwargs)
-        return stream
-
-    def joinpath(self, name):
-        raise RuntimeError("Cannot traverse into a resource")
-
-
-class ResourceContainer(Traversable):
-    """
-    Traversable container for a package's resources via its reader.
-    """
-
-    def __init__(self, reader):
-        # type: (SimpleReader) -> None
-        self.reader = reader
-
-    def is_dir(self):
-        return True
-
-    def is_file(self):
-        return False
-
-    def iterdir(self):
-        files = (ResourceHandle(self, name) for name in self.reader.resources)
-        dirs = map(ResourceContainer, self.reader.children())
-        return itertools.chain(files, dirs)
-
-    def open(self, *args, **kwargs):
-        raise IsADirectoryError()
-
-    def joinpath(self, name):
-        return next(
-            traversable for traversable in self.iterdir() if traversable.name == name
-        )
-
-
-class TraversableReader(TraversableResources, SimpleReader):
-    """
-    A TraversableResources based on SimpleReader. Resource providers
-    may derive from this class to provide the TraversableResources
-    interface by supplying the SimpleReader interface.
-    """
-
-    def files(self):
-        return ResourceContainer(self)
diff --git a/importlib_resources/simple.py b/importlib_resources/simple.py
new file mode 100644
index 00000000..da073cbd
--- /dev/null
+++ b/importlib_resources/simple.py
@@ -0,0 +1,116 @@
+"""
+Interface adapters for low-level readers.
+"""
+
+import abc
+import io
+import itertools
+from typing import BinaryIO, List
+
+from .abc import Traversable, TraversableResources
+
+
+class SimpleReader(abc.ABC):
+    """
+    The minimum, low-level interface required from a resource
+    provider.
+    """
+
+    @abc.abstractproperty
+    def package(self):
+        # type: () -> str
+        """
+        The name of the package for which this reader loads resources.
+        """
+
+    @abc.abstractmethod
+    def children(self):
+        # type: () -> List['SimpleReader']
+        """
+        Obtain an iterable of SimpleReader for available
+        child containers (e.g. directories).
+        """
+
+    @abc.abstractmethod
+    def resources(self):
+        # type: () -> List[str]
+        """
+        Obtain available named resources for this virtual package.
+        """
+
+    @abc.abstractmethod
+    def open_binary(self, resource):
+        # type: (str) -> BinaryIO
+        """
+        Obtain a File-like for a named resource.
+        """
+
+    @property
+    def name(self):
+        return self.package.split('.')[-1]
+
+
+class ResourceHandle(Traversable):
+    """
+    Handle to a named resource in a ResourceReader.
+    """
+
+    def __init__(self, parent, name):
+        # type: (ResourceContainer, str) -> None
+        self.parent = parent
+        self.name = name  # type: ignore
+
+    def is_file(self):
+        return True
+
+    def is_dir(self):
+        return False
+
+    def open(self, mode='r', *args, **kwargs):
+        stream = self.parent.reader.open_binary(self.name)
+        if 'b' not in mode:
+            stream = io.TextIOWrapper(*args, **kwargs)
+        return stream
+
+    def joinpath(self, name):
+        raise RuntimeError("Cannot traverse into a resource")
+
+
+class ResourceContainer(Traversable):
+    """
+    Traversable container for a package's resources via its reader.
+    """
+
+    def __init__(self, reader):
+        # type: (SimpleReader) -> None
+        self.reader = reader
+
+    def is_dir(self):
+        return True
+
+    def is_file(self):
+        return False
+
+    def iterdir(self):
+        files = (ResourceHandle(self, name) for name in self.reader.resources)
+        dirs = map(ResourceContainer, self.reader.children())
+        return itertools.chain(files, dirs)
+
+    def open(self, *args, **kwargs):
+        raise IsADirectoryError()
+
+    def joinpath(self, name):
+        return next(
+            traversable for traversable in self.iterdir() if traversable.name == name
+        )
+
+
+class TraversableReader(TraversableResources, SimpleReader):
+    """
+    A TraversableResources based on SimpleReader. Resource providers
+    may derive from this class to provide the TraversableResources
+    interface by supplying the SimpleReader interface.
+    """
+
+    def files(self):
+        return ResourceContainer(self)

From 446699153a9681242e951212aefdc725c0fff08c Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Mon, 18 Jan 2021 19:23:03 -0500
Subject: [PATCH 14/14] Update changelog.

---
 CHANGES.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/CHANGES.rst b/CHANGES.rst
index 995f8391..2d4d6cea 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,10 @@
+v5.1.0
+======
+
+* Added ``simple`` module implementing adapters from
+  a low-level resource reader interface to a
+  ``TraversableResources`` interface. Closes #90.
+
 v5.0.1
 ======