Imported from /home/lorry/working-area/delta_python-packages_simplegeneric-tarball/simplegeneric_0.8.1.orig.tar.bz2.HEAD simplegeneric_0.8.1.orig master

author: Lorry Tar Creator <lorry-tar-importer@baserock.org> 2012-04-01 15:38:32 +0000
committer: <> 2014-10-07 10:28:45 +0000
commit: 601fab9b154c557dfd848d531a8969f4697d1aa2 (patch)
tree: 542bc5a53bf8a907fbf1c656807c0f788f56a940
download: simplegeneric-tarball-601fab9b154c557dfd848d531a8969f4697d1aa2.tar.gz
10 files changed, 1012 insertions, 0 deletions
diff --git a/PKG-INFO b/PKG-INFO
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--- /dev/null
+++ b/PKG-INFO
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+Metadata-Version: 1.0
+Name: simplegeneric
+Version: 0.8.1
+Summary: Simple generic functions (similar to Python's own len(), pickle.dump(), etc.)
+Home-page: http://cheeseshop.python.org/pypi/simplegeneric
+Author: Phillip J. Eby
+Author-email: peak@eby-sarna.com
+License: ZPL 2.1
+Description: * New in 0.8: Source and tests are compatible with Python 3 (w/o ``setup.py``)
+        * 0.8.1: setup.py is now compatible with Python 3 as well
+        * New in 0.7: `Multiple Types or Objects`_
+        * New in 0.6: `Inspection and Extension`_, and thread-safe method registration
+        
+        The ``simplegeneric`` module lets you define simple single-dispatch
+        generic functions, akin to Python's built-in generic functions like
+        ``len()``, ``iter()`` and so on.  However, instead of using
+        specially-named methods, these generic functions use simple lookup
+        tables, akin to those used by e.g. ``pickle.dump()`` and other
+        generic functions found in the Python standard library.
+        
+        As you can see from the above examples, generic functions are actually
+        quite common in Python already, but there is no standard way to create
+        simple ones.  This library attempts to fill that gap, as generic
+        functions are an `excellent alternative to the Visitor pattern`_, as
+        well as being a great substitute for most common uses of adaptation.
+        
+        This library tries to be the simplest possible implementation of generic
+        functions, and it therefore eschews the use of multiple or predicate
+        dispatch, as well as avoiding speedup techniques such as C dispatching
+        or code generation.  But it has absolutely no dependencies, other than
+        Python 2.4, and the implementation is just a single Python module of
+        less than 100 lines.
+        
+        
+        Usage
+        -----
+        
+        Defining and using a generic function is straightforward::
+        
+        >>> from simplegeneric import generic
+        >>> @generic
+        ... def move(item, target):
+        ...     """Default implementation goes here"""
+        ...     print("what you say?!")
+        
+        >>> @move.when_type(int)
+        ... def move_int(item, target):
+        ...     print("In AD %d, %s was beginning." % (item, target))
+        
+        >>> @move.when_type(str)
+        ... def move_str(item, target):
+        ...     print("How are you %s!!" % item)
+        ...     print("All your %s are belong to us." % (target,))
+        
+        >>> zig = object()
+        >>> @move.when_object(zig)
+        ... def move_zig(item, target):
+        ...     print("You know what you %s." % (target,))
+        ...     print("For great justice!")
+        
+        >>> move(2101, "war")
+        In AD 2101, war was beginning.
+        
+        >>> move("gentlemen", "base")
+        How are you gentlemen!!
+        All your base are belong to us.
+        
+        >>> move(zig, "doing")
+        You know what you doing.
+        For great justice!
+        
+        >>> move(27.0, 56.2)
+        what you say?!
+        
+        
+        Inheritance and Allowed Types
+        -----------------------------
+        
+        Defining multiple methods for the same type or object is an error::
+        
+        >>> @move.when_type(str)
+        ... def this_is_wrong(item, target):
+        ...     pass
+        Traceback (most recent call last):
+        ...
+        TypeError: <function move...> already has method for type <...'str'>
+        
+        >>> @move.when_object(zig)
+        ... def this_is_wrong(item, target): pass
+        Traceback (most recent call last):
+        ...
+        TypeError: <function move...> already has method for object <object ...>
+        
+        And the ``when_type()`` decorator only accepts classes or types::
+        
+        >>> @move.when_type(23)
+        ... def move_23(item, target):
+        ...     print("You have no chance to survive!")
+        Traceback (most recent call last):
+        ...
+        TypeError: 23 is not a type or class
+        
+        Methods defined for supertypes are inherited following MRO order::
+        
+        >>> class MyString(str):
+        ...     """String subclass"""
+        
+        >>> move(MyString("ladies"), "drinks")
+        How are you ladies!!
+        All your drinks are belong to us.
+        
+        Classic class instances are also supported (although the lookup process
+        is slower than for new-style instances)::
+        
+        >>> class X: pass
+        >>> class Y(X): pass
+        
+        >>> @move.when_type(X)
+        ... def move_x(item, target):
+        ...     print("Someone set us up the %s!!!" % (target,))
+        
+        >>> move(X(), "bomb")
+        Someone set us up the bomb!!!
+        
+        >>> move(Y(), "dance")
+        Someone set us up the dance!!!
+        
+        
+        Multiple Types or Objects
+        -------------------------
+        
+        As a convenience, you can now pass more than one type or object to the
+        registration methods::
+        
+        >>> @generic
+        ... def isbuiltin(ob):
+        ...     return False
+        >>> @isbuiltin.when_type(int, str, float, complex, type)
+        ... @isbuiltin.when_object(None, Ellipsis)
+        ... def yes(ob):
+        ...     return True
+        
+        >>> isbuiltin(1)
+        True
+        >>> isbuiltin(object)
+        True
+        >>> isbuiltin(object())
+        False
+        >>> isbuiltin(X())
+        False
+        >>> isbuiltin(None)
+        True
+        >>> isbuiltin(Ellipsis)
+        True
+        
+        
+        Defaults and Docs
+        -----------------
+        
+        You can obtain a function's default implementation using its ``default``
+        attribute::
+        
+        >>> @move.when_type(Y)
+        ... def move_y(item, target):
+        ...     print("Someone set us up the %s!!!" % (target,))
+        ...     move.default(item, target)
+        
+        >>> move(Y(), "dance")
+        Someone set us up the dance!!!
+        what you say?!
+        
+        
+        ``help()`` and other documentation tools see generic functions as normal
+        function objects, with the same name, attributes, docstring, and module as
+        the prototype/default function::
+        
+        >>> help(move)
+        Help on function move:
+        ...
+        move(*args, **kw)
+        Default implementation goes here
+        ...
+        
+        
+        Inspection and Extension
+        ------------------------
+        
+        You can find out if a generic function has a method for a type or object using
+        the ``has_object()`` and ``has_type()`` methods::
+        
+        >>> move.has_object(zig)
+        True
+        >>> move.has_object(42)
+        False
+        
+        >>> move.has_type(X)
+        True
+        >>> move.has_type(float)
+        False
+        
+        Note that ``has_type()`` only queries whether there is a method registered for
+        the *exact* type, not subtypes or supertypes::
+        
+        >>> class Z(X): pass
+        >>> move.has_type(Z)
+        False
+        
+        You can create a generic function that "inherits" from an existing generic
+        function by calling ``generic()`` on the existing function::
+        
+        >>> move2 = generic(move)
+        >>> move(2101, "war")
+        In AD 2101, war was beginning.
+        
+        Any methods added to the new generic function override *all* methods in the
+        "base" function::
+        
+        >>> @move2.when_type(X)
+        ... def move2_X(item, target):
+        ...     print("You have no chance to survive make your %s!" % (target,))
+        
+        >>> move2(X(), "time")
+        You have no chance to survive make your time!
+        
+        >>> move2(Y(), "time")
+        You have no chance to survive make your time!
+        
+        Notice that even though ``move()`` has a method for type ``Y``, the method
+        defined for ``X`` in ``move2()`` takes precedence.  This is because the
+        ``move`` function is used as the ``default`` method of ``move2``, and ``move2``
+        has no method for type ``Y``::
+        
+        >>> move2.default is move
+        True
+        >>> move.has_type(Y)
+        True
+        >>> move2.has_type(Y)
+        False
+        
+        
+        Limitations
+        -----------
+        
+        * The first argument is always used for dispatching, and it must always be
+        passed *positionally* when the function is called.
+        
+        * Documentation tools don't see the function's original argument signature, so
+        you have to describe it in the docstring.
+        
+        * If you have optional arguments, you must duplicate them on every method in
+        order for them to work correctly.  (On the plus side, it means you can have
+        different defaults or required arguments for each method, although relying on
+        that quirk probably isn't a good idea.)
+        
+        These restrictions may be lifted in later releases, if I feel the need.  They
+        would require runtime code generation the way I do it in ``RuleDispatch``,
+        however, which is somewhat of a pain.  (Alternately I could use the
+        ``BytecodeAssembler`` package to do the code generation, as that's a lot easier
+        to use than string-based code generation, but that would introduce more
+        dependencies, and I'm trying to keep this simple so I can just
+        toss it into Chandler without a big footprint increase.)
+        
+        .. _excellent alternative to the Visitor pattern: http://peak.telecommunity.com/DevCenter/VisitorRevisited
+        
+        
+Platform: UNKNOWN
+Classifier: Development Status :: 6 - Mature
+Classifier: Development Status :: 7 - Inactive
+Classifier: Intended Audience :: Developers
+Classifier: License :: OSI Approved :: Zope Public License
+Classifier: Programming Language :: Python
+Classifier: Programming Language :: Python :: 2
+Classifier: Programming Language :: Python :: 2.4
+Classifier: Programming Language :: Python :: 2.5
+Classifier: Programming Language :: Python :: 2.6
+Classifier: Programming Language :: Python :: 2.7
+Classifier: Programming Language :: Python :: 3
+Classifier: Operating System :: OS Independent
+Classifier: Topic :: Software Development :: Libraries :: Python Modules
diff --git a/README.txt b/README.txt
new file mode 100644
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--- /dev/null
+++ b/README.txt
@@ -0,0 +1,260 @@
+=========================
+Trivial Generic Functions
+=========================
+
+* New in 0.8: Source and tests are compatible with Python 3 (w/o ``setup.py``)
+  * 0.8.1: setup.py is now compatible with Python 3 as well
+* New in 0.7: `Multiple Types or Objects`_
+* New in 0.6: `Inspection and Extension`_, and thread-safe method registration
+
+The ``simplegeneric`` module lets you define simple single-dispatch
+generic functions, akin to Python's built-in generic functions like
+``len()``, ``iter()`` and so on.  However, instead of using
+specially-named methods, these generic functions use simple lookup
+tables, akin to those used by e.g. ``pickle.dump()`` and other
+generic functions found in the Python standard library.
+
+As you can see from the above examples, generic functions are actually
+quite common in Python already, but there is no standard way to create
+simple ones.  This library attempts to fill that gap, as generic
+functions are an `excellent alternative to the Visitor pattern`_, as
+well as being a great substitute for most common uses of adaptation.
+
+This library tries to be the simplest possible implementation of generic
+functions, and it therefore eschews the use of multiple or predicate
+dispatch, as well as avoiding speedup techniques such as C dispatching
+or code generation.  But it has absolutely no dependencies, other than
+Python 2.4, and the implementation is just a single Python module of
+less than 100 lines.
+
+
+Usage
+-----
+
+Defining and using a generic function is straightforward::
+
+    >>> from simplegeneric import generic
+    >>> @generic
+    ... def move(item, target):
+    ...     """Default implementation goes here"""
+    ...     print("what you say?!")
+
+    >>> @move.when_type(int)
+    ... def move_int(item, target):
+    ...     print("In AD %d, %s was beginning." % (item, target))
+
+    >>> @move.when_type(str)
+    ... def move_str(item, target):
+    ...     print("How are you %s!!" % item)
+    ...     print("All your %s are belong to us." % (target,))
+
+    >>> zig = object()
+    >>> @move.when_object(zig)
+    ... def move_zig(item, target):
+    ...     print("You know what you %s." % (target,))
+    ...     print("For great justice!")
+
+    >>> move(2101, "war")
+    In AD 2101, war was beginning.
+
+    >>> move("gentlemen", "base")
+    How are you gentlemen!!
+    All your base are belong to us.
+
+    >>> move(zig, "doing")
+    You know what you doing.
+    For great justice!
+
+    >>> move(27.0, 56.2)
+    what you say?!
+
+
+Inheritance and Allowed Types
+-----------------------------
+
+Defining multiple methods for the same type or object is an error::
+
+    >>> @move.when_type(str)
+    ... def this_is_wrong(item, target):
+    ...     pass
+    Traceback (most recent call last):
+    ...
+    TypeError: <function move...> already has method for type <...'str'>
+
+    >>> @move.when_object(zig)
+    ... def this_is_wrong(item, target): pass
+    Traceback (most recent call last):
+      ...
+    TypeError: <function move...> already has method for object <object ...>
+
+And the ``when_type()`` decorator only accepts classes or types::
+
+    >>> @move.when_type(23)
+    ... def move_23(item, target):
+    ...     print("You have no chance to survive!")
+    Traceback (most recent call last):
+      ...
+    TypeError: 23 is not a type or class
+
+Methods defined for supertypes are inherited following MRO order::
+
+    >>> class MyString(str):
+    ...     """String subclass"""
+
+    >>> move(MyString("ladies"), "drinks")
+    How are you ladies!!
+    All your drinks are belong to us.
+
+Classic class instances are also supported (although the lookup process
+is slower than for new-style instances)::
+
+    >>> class X: pass
+    >>> class Y(X): pass
+
+    >>> @move.when_type(X)
+    ... def move_x(item, target):
+    ...     print("Someone set us up the %s!!!" % (target,))
+
+    >>> move(X(), "bomb")
+    Someone set us up the bomb!!!
+
+    >>> move(Y(), "dance")
+    Someone set us up the dance!!!
+
+
+Multiple Types or Objects
+-------------------------
+
+As a convenience, you can now pass more than one type or object to the
+registration methods::
+
+    >>> @generic
+    ... def isbuiltin(ob):
+    ...     return False
+    >>> @isbuiltin.when_type(int, str, float, complex, type)
+    ... @isbuiltin.when_object(None, Ellipsis)
+    ... def yes(ob):
+    ...     return True
+    
+    >>> isbuiltin(1)
+    True
+    >>> isbuiltin(object)
+    True
+    >>> isbuiltin(object())
+    False
+    >>> isbuiltin(X())
+    False
+    >>> isbuiltin(None)
+    True
+    >>> isbuiltin(Ellipsis)
+    True
+
+
+Defaults and Docs
+-----------------
+
+You can obtain a function's default implementation using its ``default``
+attribute::
+
+    >>> @move.when_type(Y)
+    ... def move_y(item, target):
+    ...     print("Someone set us up the %s!!!" % (target,))
+    ...     move.default(item, target)
+
+    >>> move(Y(), "dance")
+    Someone set us up the dance!!!
+    what you say?!
+
+
+``help()`` and other documentation tools see generic functions as normal
+function objects, with the same name, attributes, docstring, and module as
+the prototype/default function::
+
+    >>> help(move)
+    Help on function move:
+    ...
+    move(*args, **kw)
+        Default implementation goes here
+    ...
+
+
+Inspection and Extension
+------------------------
+
+You can find out if a generic function has a method for a type or object using
+the ``has_object()`` and ``has_type()`` methods::
+
+    >>> move.has_object(zig)
+    True
+    >>> move.has_object(42)
+    False
+
+    >>> move.has_type(X)
+    True
+    >>> move.has_type(float)
+    False
+
+Note that ``has_type()`` only queries whether there is a method registered for
+the *exact* type, not subtypes or supertypes::
+
+    >>> class Z(X): pass
+    >>> move.has_type(Z)
+    False
+
+You can create a generic function that "inherits" from an existing generic
+function by calling ``generic()`` on the existing function::
+
+    >>> move2 = generic(move)
+    >>> move(2101, "war")
+    In AD 2101, war was beginning.
+
+Any methods added to the new generic function override *all* methods in the
+"base" function::
+
+    >>> @move2.when_type(X)
+    ... def move2_X(item, target):
+    ...     print("You have no chance to survive make your %s!" % (target,))
+
+    >>> move2(X(), "time")
+    You have no chance to survive make your time!
+
+    >>> move2(Y(), "time")
+    You have no chance to survive make your time!
+
+Notice that even though ``move()`` has a method for type ``Y``, the method
+defined for ``X`` in ``move2()`` takes precedence.  This is because the
+``move`` function is used as the ``default`` method of ``move2``, and ``move2``
+has no method for type ``Y``::
+
+    >>> move2.default is move
+    True
+    >>> move.has_type(Y)
+    True
+    >>> move2.has_type(Y)
+    False
+
+
+Limitations
+-----------
+
+* The first argument is always used for dispatching, and it must always be
+  passed *positionally* when the function is called.
+
+* Documentation tools don't see the function's original argument signature, so
+  you have to describe it in the docstring.
+
+* If you have optional arguments, you must duplicate them on every method in
+  order for them to work correctly.  (On the plus side, it means you can have
+  different defaults or required arguments for each method, although relying on
+  that quirk probably isn't a good idea.)
+
+These restrictions may be lifted in later releases, if I feel the need.  They
+would require runtime code generation the way I do it in ``RuleDispatch``,
+however, which is somewhat of a pain.  (Alternately I could use the
+``BytecodeAssembler`` package to do the code generation, as that's a lot easier
+to use than string-based code generation, but that would introduce more
+dependencies, and I'm trying to keep this simple so I can just
+toss it into Chandler without a big footprint increase.)
+
+.. _excellent alternative to the Visitor pattern: http://peak.telecommunity.com/DevCenter/VisitorRevisited
+
diff --git a/classifiers.txt b/classifiers.txt
new file mode 100644
index 0000000..1636f70
--- /dev/null
+++ b/classifiers.txt
@@ -0,0 +1,14 @@
+Development Status :: 6 - Mature
+Development Status :: 7 - Inactive
+Intended Audience :: Developers
+License :: OSI Approved :: Zope Public License
+Programming Language :: Python
+Programming Language :: Python :: 2
+Programming Language :: Python :: 2.4
+Programming Language :: Python :: 2.5
+Programming Language :: Python :: 2.6
+Programming Language :: Python :: 2.7
+Programming Language :: Python :: 3
+Operating System :: OS Independent
+Topic :: Software Development :: Libraries :: Python Modules
+
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..b14b0bc
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,5 @@
+[egg_info]
+tag_build = 
+tag_date = 0
+tag_svn_revision = 0
+
diff --git a/setup.py b/setup.py
new file mode 100644
index 0000000..0fd9747
--- /dev/null
+++ b/setup.py
@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+"""Distutils setup file"""
+try:
+    from setuptools import setup
+except ImportError:
+    from distutils.core import setup
+
+# Metadata
+PACKAGE_NAME = "simplegeneric"
+PACKAGE_VERSION = "0.8.1"
+
+def get_description():
+    # Get our long description from the documentation
+    f = open('README.txt')
+    lines = []
+    for line in f:
+        if not line.strip():
+            break     # skip to first blank line
+    for line in f:
+        if line.startswith('.. contents::'):
+            break     # read to table of contents
+        lines.append(line)
+    f.close()
+    return ''.join(lines)
+
+setup(
+    name=PACKAGE_NAME,
+    version=PACKAGE_VERSION,
+    description= "Simple generic functions (similar to Python's own len(), "
+        "pickle.dump(), etc.)",
+    long_description = get_description(),
+    url = "http://cheeseshop.python.org/pypi/simplegeneric",
+    author="Phillip J. Eby",
+    author_email="peak@eby-sarna.com",
+    license="ZPL 2.1",
+    test_suite = 'simplegeneric.test_suite',
+    py_modules = ['simplegeneric'],
+    classifiers = [
+        line.strip() for line in open('classifiers.txt') if line.strip()
+    ],
+)
diff --git a/simplegeneric.egg-info/PKG-INFO b/simplegeneric.egg-info/PKG-INFO
new file mode 100644
index 0000000..38b280c
--- /dev/null
+++ b/simplegeneric.egg-info/PKG-INFO
@@ -0,0 +1,279 @@
+Metadata-Version: 1.0
+Name: simplegeneric
+Version: 0.8.1
+Summary: Simple generic functions (similar to Python's own len(), pickle.dump(), etc.)
+Home-page: http://cheeseshop.python.org/pypi/simplegeneric
+Author: Phillip J. Eby
+Author-email: peak@eby-sarna.com
+License: ZPL 2.1
+Description: * New in 0.8: Source and tests are compatible with Python 3 (w/o ``setup.py``)
+        * 0.8.1: setup.py is now compatible with Python 3 as well
+        * New in 0.7: `Multiple Types or Objects`_
+        * New in 0.6: `Inspection and Extension`_, and thread-safe method registration
+        
+        The ``simplegeneric`` module lets you define simple single-dispatch
+        generic functions, akin to Python's built-in generic functions like
+        ``len()``, ``iter()`` and so on.  However, instead of using
+        specially-named methods, these generic functions use simple lookup
+        tables, akin to those used by e.g. ``pickle.dump()`` and other
+        generic functions found in the Python standard library.
+        
+        As you can see from the above examples, generic functions are actually
+        quite common in Python already, but there is no standard way to create
+        simple ones.  This library attempts to fill that gap, as generic
+        functions are an `excellent alternative to the Visitor pattern`_, as
+        well as being a great substitute for most common uses of adaptation.
+        
+        This library tries to be the simplest possible implementation of generic
+        functions, and it therefore eschews the use of multiple or predicate
+        dispatch, as well as avoiding speedup techniques such as C dispatching
+        or code generation.  But it has absolutely no dependencies, other than
+        Python 2.4, and the implementation is just a single Python module of
+        less than 100 lines.
+        
+        
+        Usage
+        -----
+        
+        Defining and using a generic function is straightforward::
+        
+        >>> from simplegeneric import generic
+        >>> @generic
+        ... def move(item, target):
+        ...     """Default implementation goes here"""
+        ...     print("what you say?!")
+        
+        >>> @move.when_type(int)
+        ... def move_int(item, target):
+        ...     print("In AD %d, %s was beginning." % (item, target))
+        
+        >>> @move.when_type(str)
+        ... def move_str(item, target):
+        ...     print("How are you %s!!" % item)
+        ...     print("All your %s are belong to us." % (target,))
+        
+        >>> zig = object()
+        >>> @move.when_object(zig)
+        ... def move_zig(item, target):
+        ...     print("You know what you %s." % (target,))
+        ...     print("For great justice!")
+        
+        >>> move(2101, "war")
+        In AD 2101, war was beginning.
+        
+        >>> move("gentlemen", "base")
+        How are you gentlemen!!
+        All your base are belong to us.
+        
+        >>> move(zig, "doing")
+        You know what you doing.
+        For great justice!
+        
+        >>> move(27.0, 56.2)
+        what you say?!
+        
+        
+        Inheritance and Allowed Types
+        -----------------------------
+        
+        Defining multiple methods for the same type or object is an error::
+        
+        >>> @move.when_type(str)
+        ... def this_is_wrong(item, target):
+        ...     pass
+        Traceback (most recent call last):
+        ...
+        TypeError: <function move...> already has method for type <...'str'>
+        
+        >>> @move.when_object(zig)
+        ... def this_is_wrong(item, target): pass
+        Traceback (most recent call last):
+        ...
+        TypeError: <function move...> already has method for object <object ...>
+        
+        And the ``when_type()`` decorator only accepts classes or types::
+        
+        >>> @move.when_type(23)
+        ... def move_23(item, target):
+        ...     print("You have no chance to survive!")
+        Traceback (most recent call last):
+        ...
+        TypeError: 23 is not a type or class
+        
+        Methods defined for supertypes are inherited following MRO order::
+        
+        >>> class MyString(str):
+        ...     """String subclass"""
+        
+        >>> move(MyString("ladies"), "drinks")
+        How are you ladies!!
+        All your drinks are belong to us.
+        
+        Classic class instances are also supported (although the lookup process
+        is slower than for new-style instances)::
+        
+        >>> class X: pass
+        >>> class Y(X): pass
+        
+        >>> @move.when_type(X)
+        ... def move_x(item, target):
+        ...     print("Someone set us up the %s!!!" % (target,))
+        
+        >>> move(X(), "bomb")
+        Someone set us up the bomb!!!
+        
+        >>> move(Y(), "dance")
+        Someone set us up the dance!!!
+        
+        
+        Multiple Types or Objects
+        -------------------------
+        
+        As a convenience, you can now pass more than one type or object to the
+        registration methods::
+        
+        >>> @generic
+        ... def isbuiltin(ob):
+        ...     return False
+        >>> @isbuiltin.when_type(int, str, float, complex, type)
+        ... @isbuiltin.when_object(None, Ellipsis)
+        ... def yes(ob):
+        ...     return True
+        
+        >>> isbuiltin(1)
+        True
+        >>> isbuiltin(object)
+        True
+        >>> isbuiltin(object())
+        False
+        >>> isbuiltin(X())
+        False
+        >>> isbuiltin(None)
+        True
+        >>> isbuiltin(Ellipsis)
+        True
+        
+        
+        Defaults and Docs
+        -----------------
+        
+        You can obtain a function's default implementation using its ``default``
+        attribute::
+        
+        >>> @move.when_type(Y)
+        ... def move_y(item, target):
+        ...     print("Someone set us up the %s!!!" % (target,))
+        ...     move.default(item, target)
+        
+        >>> move(Y(), "dance")
+        Someone set us up the dance!!!
+        what you say?!
+        
+        
+        ``help()`` and other documentation tools see generic functions as normal
+        function objects, with the same name, attributes, docstring, and module as
+        the prototype/default function::
+        
+        >>> help(move)
+        Help on function move:
+        ...
+        move(*args, **kw)
+        Default implementation goes here
+        ...
+        
+        
+        Inspection and Extension
+        ------------------------
+        
+        You can find out if a generic function has a method for a type or object using
+        the ``has_object()`` and ``has_type()`` methods::
+        
+        >>> move.has_object(zig)
+        True
+        >>> move.has_object(42)
+        False
+        
+        >>> move.has_type(X)
+        True
+        >>> move.has_type(float)
+        False
+        
+        Note that ``has_type()`` only queries whether there is a method registered for
+        the *exact* type, not subtypes or supertypes::
+        
+        >>> class Z(X): pass
+        >>> move.has_type(Z)
+        False
+        
+        You can create a generic function that "inherits" from an existing generic
+        function by calling ``generic()`` on the existing function::
+        
+        >>> move2 = generic(move)
+        >>> move(2101, "war")
+        In AD 2101, war was beginning.
+        
+        Any methods added to the new generic function override *all* methods in the
+        "base" function::
+        
+        >>> @move2.when_type(X)
+        ... def move2_X(item, target):
+        ...     print("You have no chance to survive make your %s!" % (target,))
+        
+        >>> move2(X(), "time")
+        You have no chance to survive make your time!
+        
+        >>> move2(Y(), "time")
+        You have no chance to survive make your time!
+        
+        Notice that even though ``move()`` has a method for type ``Y``, the method
+        defined for ``X`` in ``move2()`` takes precedence.  This is because the
+        ``move`` function is used as the ``default`` method of ``move2``, and ``move2``
+        has no method for type ``Y``::
+        
+        >>> move2.default is move
+        True
+        >>> move.has_type(Y)
+        True
+        >>> move2.has_type(Y)
+        False
+        
+        
+        Limitations
+        -----------
+        
+        * The first argument is always used for dispatching, and it must always be
+        passed *positionally* when the function is called.
+        
+        * Documentation tools don't see the function's original argument signature, so
+        you have to describe it in the docstring.
+        
+        * If you have optional arguments, you must duplicate them on every method in
+        order for them to work correctly.  (On the plus side, it means you can have
+        different defaults or required arguments for each method, although relying on
+        that quirk probably isn't a good idea.)
+        
+        These restrictions may be lifted in later releases, if I feel the need.  They
+        would require runtime code generation the way I do it in ``RuleDispatch``,
+        however, which is somewhat of a pain.  (Alternately I could use the
+        ``BytecodeAssembler`` package to do the code generation, as that's a lot easier
+        to use than string-based code generation, but that would introduce more
+        dependencies, and I'm trying to keep this simple so I can just
+        toss it into Chandler without a big footprint increase.)
+        
+        .. _excellent alternative to the Visitor pattern: http://peak.telecommunity.com/DevCenter/VisitorRevisited
+        
+        
+Platform: UNKNOWN
+Classifier: Development Status :: 6 - Mature
+Classifier: Development Status :: 7 - Inactive
+Classifier: Intended Audience :: Developers
+Classifier: License :: OSI Approved :: Zope Public License
+Classifier: Programming Language :: Python
+Classifier: Programming Language :: Python :: 2
+Classifier: Programming Language :: Python :: 2.4
+Classifier: Programming Language :: Python :: 2.5
+Classifier: Programming Language :: Python :: 2.6
+Classifier: Programming Language :: Python :: 2.7
+Classifier: Programming Language :: Python :: 3
+Classifier: Operating System :: OS Independent
+Classifier: Topic :: Software Development :: Libraries :: Python Modules
diff --git a/simplegeneric.egg-info/SOURCES.txt b/simplegeneric.egg-info/SOURCES.txt
new file mode 100644
index 0000000..2b3e36a
--- /dev/null
+++ b/simplegeneric.egg-info/SOURCES.txt
@@ -0,0 +1,9 @@
+README.txt
+classifiers.txt
+setup.cfg
+setup.py
+simplegeneric.py
+simplegeneric.egg-info/PKG-INFO
+simplegeneric.egg-info/SOURCES.txt
+simplegeneric.egg-info/dependency_links.txt
+simplegeneric.egg-info/top_level.txt
+\ No newline at end of file
diff --git a/simplegeneric.egg-info/dependency_links.txt b/simplegeneric.egg-info/dependency_links.txt
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/simplegeneric.egg-info/dependency_links.txt
@@ -0,0 +1 @@
+
diff --git a/simplegeneric.egg-info/top_level.txt b/simplegeneric.egg-info/top_level.txt
new file mode 100644
index 0000000..ec4d598
--- /dev/null
+++ b/simplegeneric.egg-info/top_level.txt
@@ -0,0 +1 @@
+simplegeneric
diff --git a/simplegeneric.py b/simplegeneric.py
new file mode 100644
index 0000000..bd12c14
--- /dev/null
+++ b/simplegeneric.py
@@ -0,0 +1,123 @@
+__all__ = ["generic"]
+try:
+    from types import ClassType, InstanceType
+    classtypes = type, ClassType
+except ImportError:
+    classtypes = type
+    InstanceType = None
+
+def generic(func):
+    """Create a simple generic function"""
+
+    _sentinel = object()
+
+    def _by_class(*args, **kw):
+        cls = args[0].__class__
+        for t in type(cls.__name__, (cls,object), {}).__mro__:
+            f = _gbt(t, _sentinel)
+            if f is not _sentinel:
+                return f(*args, **kw)
+        else:
+            return func(*args, **kw)
+
+    _by_type = {object: func, InstanceType: _by_class}
+    _gbt = _by_type.get
+
+    def when_type(*types):
+        """Decorator to add a method that will be called for the given types"""
+        for t in types:
+            if not isinstance(t, classtypes):
+                raise TypeError(
+                    "%r is not a type or class" % (t,)
+                )
+        def decorate(f):
+            for t in types:
+                if _by_type.setdefault(t,f) is not f:
+                    raise TypeError(
+                        "%r already has method for type %r" % (func, t)
+                    )
+            return f
+        return decorate
+
+    _by_object = {}
+    _gbo = _by_object.get
+
+    def when_object(*obs):
+        """Decorator to add a method to be called for the given object(s)"""
+        def decorate(f):
+            for o in obs:
+                if _by_object.setdefault(id(o), (o,f))[1] is not f:
+                    raise TypeError(
+                        "%r already has method for object %r" % (func, o)
+                    )
+            return f
+        return decorate
+
+
+    def dispatch(*args, **kw):
+        f = _gbo(id(args[0]), _sentinel)
+        if f is _sentinel:
+            for t in type(args[0]).__mro__:
+                f = _gbt(t, _sentinel)
+                if f is not _sentinel:
+                    return f(*args, **kw)
+            else:
+                return func(*args, **kw)
+        else:
+            return f[1](*args, **kw)
+
+    dispatch.__name__       = func.__name__
+    dispatch.__dict__       = func.__dict__.copy()
+    dispatch.__doc__        = func.__doc__
+    dispatch.__module__     = func.__module__
+
+    dispatch.when_type = when_type
+    dispatch.when_object = when_object
+    dispatch.default = func
+    dispatch.has_object = lambda o: id(o) in _by_object
+    dispatch.has_type   = lambda t: t in _by_type
+    return dispatch
+
+
+
+def test_suite():
+    import doctest
+    return doctest.DocFileSuite(
+        'README.txt',
+        optionflags=doctest.ELLIPSIS|doctest.REPORT_ONLY_FIRST_FAILURE,
+    )
+
+if __name__=='__main__':
+    import unittest
+    r = unittest.TextTestRunner()
+    r.run(test_suite())
+
+
+
+
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author	Lorry Tar Creator <lorry-tar-importer@baserock.org>	2012-04-01 15:38:32 +0000
committer	<>	2014-10-07 10:28:45 +0000
commit	601fab9b154c557dfd848d531a8969f4697d1aa2 (patch)
tree	542bc5a53bf8a907fbf1c656807c0f788f56a940
download	simplegeneric-tarball-601fab9b154c557dfd848d531a8969f4697d1aa2.tar.gz