Sorta an initial check-in.

This is broken out from a week-long development cycle for the
[Hy](http://docs.hylang.org/en/latest/) programming language,
which I can't recommend enough.

.gitignore

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+*~
+*.swp
+db.sqlite3
+bower_components
+*.pyc
+\#*#
+.#*
+catalogia/settings.hy

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2004-2016 Elf M. Sternberg <elf.sternberg@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

MANIFEST.in

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+include *.py
+include LICENSE
+exclude run_tests.py
+exclude requirements.txt
+exclude README.md
+recursive-include *.py
+prune tests

README.rst

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+_polyloader_ is a python module to hook into Python's import machinery
+and insert your own syntax parser/recognizer.  Importlib uses filename
+suffixes to recognize which compiler to use, but is internally
+hard-coded to only recognize ".py" as a valid suffix.
+
+## To use:
+
+Import polyloader in your python script's launcher or library, as well
+as the syntax compiler(s) you plan to use.  For example, if you have
+[Mochi](https://github.com/i2y/mochi)) and
+[Hy](http://docs.hylang.org/en/latest/) installed, and you wanted to
+write a Django app, edit manage.py and add the following lines at the
+top:
+
+.. code:: python
+    from mochi.main import compile_file as mochi_compile
+    from hy.importer import ast_compile as hy_compile
+    from polyloader import polyimport
+    polyimport(mochi_compile, ['.mochi'])
+    polyimport(hy_compile, ['.hy'])
+
+Now your views can be written in Hy and your models in Mochi, and
+everything will just work.
+
+## Dependencies
+
+polymorph is self-contained. It has no dependencies other than Python
+itself and your choice of language.
+

polyloader.py

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+# polyloader.py 
+#
+# Copyright (c) 2016 Elf M. Sternberg <elf.sternberg@gmail.com>
+# 
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+# DEALINGS IN THE SOFTWARE.
+#
+
+""" Utilities for initializing extended path-hooks into the Python runtime """
+__all__ = []  # Exports nothing; this module is called for its side-effects
+
+import os
+import sys
+
+from importlib import machinery
+from importlib.machinery import SOURCE_SUFFIXES as PY_SOURCE_SUFFIXES
+from pkgutil import iter_importer_modules
+
+try:
+    from importlib._bootstrap import _get_supported_file_loaders
+except:
+    from importlib._bootstrap_external import _get_supported_file_loaders
+
+__author__ = 'Elf M. Sternberg'
+__version__ = '2016.05.29'
+__contact__ = 'elf.sternberg@gmail.com'
+
+def _call_with_frames_removed(f, *args, **kwds):
+    # Hack.  This function name and signature is hard-coded into
+    # Python's import.c.  The name and signature trigger importlib to
+    # remove itself from any stacktraces.  See import.c for details.
+    return f(*args, **kwds)
+
+
+class ExtendedSourceFileLoader(machinery.SourceFileLoader):
+    """Override the get_code method.  Falls back on the SourceFileLoader
+       if it's a Python file, which will generate pyc files as needed,
+       or works its way into the Extended version.  This method does
+       not yet address the generation of .pyc/.pyo files from source
+       files.
+
+    """
+
+    _source_handlers = []
+
+    @classmethod
+    def get_extended_suffixes(cls):
+        suffixes = [] 
+        for compiler, csuffx in cls._source_handlers:
+            suffixes = suffixes + list(csuffx)
+        return suffixes
+
+    @classmethod
+    def get_extended_suffixes_inclusive(cls):
+        return PY_SOURCE_SUFFIXES + cls.get_extended_suffixes()
+
+    # TODO: Address the generation of .pyc/.pyo files from source files.
+    # See importlib/_bootstrap.py for details is SourceFileLoader of
+    # how that's done.
+    def get_code(self, fullname):
+        source_path = self.get_filename(fullname)
+        if source_path.endswith(tuple(PY_SOURCE_SUFFIXES)):
+            return super(ExtendedSourceFileLoader, self).get_code(fullname)
+
+        for compiler, suffixes in self._source_handlers:
+            if source_path.endswith(suffixes):
+                return compiler(source_path, fullname)
+        else:
+            raise ImportError("Could not find compiler for %s (%s)" % (fullname, source_path))
+
+# Provide a working namespace for our new FileFinder.
+class ExtendedFileFinder(machinery.FileFinder):
+
+    # Taken from inspect.py and modified to support alternate suffixes.
+    @staticmethod
+    def getmodulename(path):
+        fname = os.path.basename(path)
+        suffixes = [(-len(suffix), suffix)
+                    for suffix in (machinery.all_suffixes() + 
+                                   ExtendedSourceFileLoader.get_extended_suffixes())]
+        suffixes.sort()  # try longest suffixes first, in case they overlap
+        for neglen, suffix in suffixes:
+            if fname.endswith(suffix):
+                return fname[:neglen]
+        return None
+
+    # Taken from pkgutil.py and modified to support alternate suffixes.
+    @staticmethod
+    def iter_modules(importer, prefix=''):
+        if importer.path is None or not os.path.isdir(importer.path):
+            return
+
+        yielded = {}
+        try:
+            filenames = os.listdir(importer.path)
+        except OSError:
+            # ignore unreadable directories like import does
+            filenames = []
+        filenames.sort()  # handle packages before same-named modules
+
+        for fn in filenames:
+            modname = ExtendedFileFinder.getmodulename(fn)
+            if modname == '__init__' or modname in yielded:
+                continue
+
+            path = os.path.join(importer.path, fn)
+            ispkg = False
+
+            if not modname and os.path.isdir(path) and '.' not in fn:
+                modname = fn
+                try:
+                    dircontents = os.listdir(path)
+                except OSError:
+                    # ignore unreadable directories like import does
+                    dircontents = []
+                for fn in dircontents:
+                    subname = ExtendedFileFinder.getmodulename(fn)
+                    if subname == '__init__':
+                        ispkg = True
+                        break
+                else:
+                    continue    # not a package
+
+            if modname and '.' not in modname:
+                yielded[modname] = 1
+                yield prefix + modname, ispkg
+        pass
+
+
+# Monkeypatch both path_hooks and iter_importer_modules to make our
+# modules recognizable to the module iterator functions.  This is
+# probably horribly fragile, but there doesn't seem to be a more
+# robust way of doing it at the moment, and these names are stable
+# from python 2.7 up.
+
+def install(compiler, suffixes):
+    """ Install a compiler and suffix(es) into Python's sys.path_hooks, so
+        that modules ending with thoses suffixes will be parsed into 
+        python executable modules automatically.  
+    """
+
+    filefinder = [(f, i) for i, f in enumerate(sys.path_hooks)
+                  if repr(f).find('path_hook_for_FileFinder') != -1]
+    if not filefinder:
+        return
+    filefinder, fpos = filefinder[0]
+
+    ExtendedSourceFileLoader._source_handlers = (ExtendedSourceFileLoader._source_handlers +
+                                                 [(compiler, tuple(suffixes))])
+
+    supported_loaders = _get_supported_file_loaders()
+    sourceloader = [(l, i) for i, l in enumerate(supported_loaders)
+                    if repr(l[0]).find('importlib.SourceFileLoader') != -1]
+    if not sourceloader:
+        return
+
+    sourceloader, spos = sourceloader[0]
+    supported_loaders[spos] = (ExtendedSourceFileLoader,
+                               ExtendedSourceFileLoader.get_extended_suffixes_inclusive())
+    sys.path_hooks[fpos] = ExtendedFileFinder.path_hook(*supported_loaders)
+    iter_importer_modules.register(ExtendedFileFinder, ExtendedFileFinder.iter_modules)
+    if sys.path[0] !== "":
+        sys.path.insert(0, "")

requirements.txt

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+future

run_tests.py

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+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+"""Script to run the tests."""
+
+import sys
+from unittest import TestLoader, TextTestRunner
+
+# Change PYTHONPATH to include pefile.
+sys.path.insert(0, u'.')
+
+if __name__ == '__main__':
+  test_suite = TestLoader().discover('./tests', pattern='*_test.py')
+  test_results = TextTestRunner(verbosity=2).run(test_suite)
+  if not test_results.wasSuccessful():
+    sys.exit(1)

setup.py

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+#!/usr/bin/python
+
+import ast
+import os
+import re
+import sys
+
+try:
+    from setuptools import setup, Command
+except ImportError as excp:
+    from distutils.core import setup, Command
+
+from unittest import TestLoader, TextTestRunner
+
+
+os.environ['COPY_EXTENDED_ATTRIBUTES_DISABLE'] = 'true'
+os.environ['COPYFILE_DISABLE'] = 'true'
+
+
+def _read_doc():
+    """
+    Parse docstring from file 'polyloader.py' and avoid importing
+    this module directly.
+    """
+    with open('polyloader.py', 'r') as f:
+        tree = ast.parse(f.read())
+    return ast.get_docstring(tree)
+
+
+def _read_attr(attr_name):
+    """
+    Parse attribute from file 'polyloader.py' and avoid importing
+    this module directly.
+
+    __version__, __author__, __contact__,
+    """
+    regex = attr_name + r"\s+=\s+'(.+)'"
+    with open('polyloader.py', 'r') as f:
+        match = re.search(regex, f.read())
+    # Second item in the group is the value of attribute.
+    return match.group(1)
+
+
+class TestCommand(Command):
+  """Run tests."""
+  user_options = []
+
+  def initialize_options(self):
+    pass
+
+  def finalize_options(self):
+    pass
+
+
+polyloader_version = _read_attr('__version__')
+if 'bdist_msi' in sys.argv:
+    polyloader_version, _, _ = polyloader_version.partition('-')
+
+
+class TestCommand(Command):
+  """Run tests."""
+  user_options = []
+
+  def initialize_options(self):
+    pass
+
+  def finalize_options(self):
+    pass
+
+  def run(self):
+    test_suite = TestLoader().discover('./tests', pattern='*_test.py')
+    test_results = TextTestRunner(verbosity=2).run(test_suite)
+
+
+setup(name = 'polyloader',
+    version = polyloader_version,
+    description = 'Python artbitrary syntax import hooks',
+    author = _read_attr('__author__'),
+    author_email = _read_attr('__contact__'),
+    url = 'https://github.com/elfsternberg/py-polymorphic-loader',
+    keywords = ['python', 'import', 'language', 'hy', 'mochi'],
+    classifiers = [
+        'Development Status :: 3 - Alpha',
+    	'Intended Audience :: Developers',
+    	'Natural Language :: English',
+    	'Operating System :: OS Independent',
+    	'Programming Language :: Python',
+    	'Topic :: Software Development :: Libraries :: Python Modules'],
+    long_description = "\n".join(_read_doc().split('\n')),
+    cmdclass={"test": TestCommand},
+    py_modules = ['polyloader'],
+    install_requires=[
+          'future',
+    ],
+)