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author | Damien George <damien.p.george@gmail.com> | 2015-08-14 12:24:11 +0100 |
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committer | Damien George <damien.p.george@gmail.com> | 2015-08-17 12:51:26 +0100 |
commit | 65dc960e3b22a8426e369607e47c19b380ce30ea (patch) | |
tree | 5e55ec2861df54e14fdb0eac1d030b34f684743b /tests/bytecode/pylib-tests/contextlib.py | |
parent | 0e978349a5e7696aa44a0faf5d046081a0616ca5 (diff) | |
download | micropython-65dc960e3b22a8426e369607e47c19b380ce30ea.tar.gz micropython-65dc960e3b22a8426e369607e47c19b380ce30ea.zip |
unix-cpy: Remove unix-cpy. It's no longer needed.
unix-cpy was originally written to get semantic equivalent with CPython
without writing functional tests. When writing the initial
implementation of uPy it was a long way between lexer and functional
tests, so the half-way test was to make sure that the bytecode was
correct. The idea was that if the uPy bytecode matched CPython 1-1 then
uPy would be proper Python if the bytecodes acted correctly. And having
matching bytecode meant that it was less likely to miss some deep
subtlety in the Python semantics that would require an architectural
change later on.
But that is all history and it no longer makes sense to retain the
ability to output CPython bytecode, because:
1. It outputs CPython 3.3 compatible bytecode. CPython's bytecode
changes from version to version, and seems to have changed quite a bit
in 3.5. There's no point in changing the bytecode output to match
CPython anymore.
2. uPy and CPy do different optimisations to the bytecode which makes it
harder to match.
3. The bytecode tests are not run. They were never part of Travis and
are not run locally anymore.
4. The EMIT_CPYTHON option needs a lot of extra source code which adds
heaps of noise, especially in compile.c.
5. Now that there is an extensive test suite (which tests functionality)
there is no need to match the bytecode. Some very subtle behaviour is
tested with the test suite and passing these tests is a much better
way to stay Python-language compliant, rather than trying to match
CPy bytecode.
Diffstat (limited to 'tests/bytecode/pylib-tests/contextlib.py')
-rw-r--r-- | tests/bytecode/pylib-tests/contextlib.py | 255 |
1 files changed, 0 insertions, 255 deletions
diff --git a/tests/bytecode/pylib-tests/contextlib.py b/tests/bytecode/pylib-tests/contextlib.py deleted file mode 100644 index 0b6bf71b08..0000000000 --- a/tests/bytecode/pylib-tests/contextlib.py +++ /dev/null @@ -1,255 +0,0 @@ -"""Utilities for with-statement contexts. See PEP 343.""" - -import sys -from collections import deque -from functools import wraps - -__all__ = ["contextmanager", "closing", "ContextDecorator", "ExitStack"] - - -class ContextDecorator(object): - "A base class or mixin that enables context managers to work as decorators." - - def _recreate_cm(self): - """Return a recreated instance of self. - - Allows an otherwise one-shot context manager like - _GeneratorContextManager to support use as - a decorator via implicit recreation. - - This is a private interface just for _GeneratorContextManager. - See issue #11647 for details. - """ - return self - - def __call__(self, func): - @wraps(func) - def inner(*args, **kwds): - with self._recreate_cm(): - return func(*args, **kwds) - return inner - - -class _GeneratorContextManager(ContextDecorator): - """Helper for @contextmanager decorator.""" - - def __init__(self, func, *args, **kwds): - self.gen = func(*args, **kwds) - self.func, self.args, self.kwds = func, args, kwds - - def _recreate_cm(self): - # _GCM instances are one-shot context managers, so the - # CM must be recreated each time a decorated function is - # called - return self.__class__(self.func, *self.args, **self.kwds) - - def __enter__(self): - try: - return next(self.gen) - except StopIteration: - raise RuntimeError("generator didn't yield") - - def __exit__(self, type, value, traceback): - if type is None: - try: - next(self.gen) - except StopIteration: - return - else: - raise RuntimeError("generator didn't stop") - else: - if value is None: - # Need to force instantiation so we can reliably - # tell if we get the same exception back - value = type() - try: - self.gen.throw(type, value, traceback) - raise RuntimeError("generator didn't stop after throw()") - except StopIteration as exc: - # Suppress the exception *unless* it's the same exception that - # was passed to throw(). This prevents a StopIteration - # raised inside the "with" statement from being suppressed - return exc is not value - except: - # only re-raise if it's *not* the exception that was - # passed to throw(), because __exit__() must not raise - # an exception unless __exit__() itself failed. But throw() - # has to raise the exception to signal propagation, so this - # fixes the impedance mismatch between the throw() protocol - # and the __exit__() protocol. - # - if sys.exc_info()[1] is not value: - raise - - -def contextmanager(func): - """@contextmanager decorator. - - Typical usage: - - @contextmanager - def some_generator(<arguments>): - <setup> - try: - yield <value> - finally: - <cleanup> - - This makes this: - - with some_generator(<arguments>) as <variable>: - <body> - - equivalent to this: - - <setup> - try: - <variable> = <value> - <body> - finally: - <cleanup> - - """ - @wraps(func) - def helper(*args, **kwds): - return _GeneratorContextManager(func, *args, **kwds) - return helper - - -class closing(object): - """Context to automatically close something at the end of a block. - - Code like this: - - with closing(<module>.open(<arguments>)) as f: - <block> - - is equivalent to this: - - f = <module>.open(<arguments>) - try: - <block> - finally: - f.close() - - """ - def __init__(self, thing): - self.thing = thing - def __enter__(self): - return self.thing - def __exit__(self, *exc_info): - self.thing.close() - - -# Inspired by discussions on http://bugs.python.org/issue13585 -class ExitStack(object): - """Context manager for dynamic management of a stack of exit callbacks - - For example: - - with ExitStack() as stack: - files = [stack.enter_context(open(fname)) for fname in filenames] - # All opened files will automatically be closed at the end of - # the with statement, even if attempts to open files later - # in the list raise an exception - - """ - def __init__(self): - self._exit_callbacks = deque() - - def pop_all(self): - """Preserve the context stack by transferring it to a new instance""" - new_stack = type(self)() - new_stack._exit_callbacks = self._exit_callbacks - self._exit_callbacks = deque() - return new_stack - - def _push_cm_exit(self, cm, cm_exit): - """Helper to correctly register callbacks to __exit__ methods""" - def _exit_wrapper(*exc_details): - return cm_exit(cm, *exc_details) - _exit_wrapper.__self__ = cm - self.push(_exit_wrapper) - - def push(self, exit): - """Registers a callback with the standard __exit__ method signature - - Can suppress exceptions the same way __exit__ methods can. - - Also accepts any object with an __exit__ method (registering a call - to the method instead of the object itself) - """ - # We use an unbound method rather than a bound method to follow - # the standard lookup behaviour for special methods - _cb_type = type(exit) - try: - exit_method = _cb_type.__exit__ - except AttributeError: - # Not a context manager, so assume its a callable - self._exit_callbacks.append(exit) - else: - self._push_cm_exit(exit, exit_method) - return exit # Allow use as a decorator - - def callback(self, callback, *args, **kwds): - """Registers an arbitrary callback and arguments. - - Cannot suppress exceptions. - """ - def _exit_wrapper(exc_type, exc, tb): - callback(*args, **kwds) - # We changed the signature, so using @wraps is not appropriate, but - # setting __wrapped__ may still help with introspection - _exit_wrapper.__wrapped__ = callback - self.push(_exit_wrapper) - return callback # Allow use as a decorator - - def enter_context(self, cm): - """Enters the supplied context manager - - If successful, also pushes its __exit__ method as a callback and - returns the result of the __enter__ method. - """ - # We look up the special methods on the type to match the with statement - _cm_type = type(cm) - _exit = _cm_type.__exit__ - result = _cm_type.__enter__(cm) - self._push_cm_exit(cm, _exit) - return result - - def close(self): - """Immediately unwind the context stack""" - self.__exit__(None, None, None) - - def __enter__(self): - return self - - def __exit__(self, *exc_details): - # We manipulate the exception state so it behaves as though - # we were actually nesting multiple with statements - frame_exc = sys.exc_info()[1] - def _fix_exception_context(new_exc, old_exc): - while 1: - exc_context = new_exc.__context__ - if exc_context in (None, frame_exc): - break - new_exc = exc_context - new_exc.__context__ = old_exc - - # Callbacks are invoked in LIFO order to match the behaviour of - # nested context managers - suppressed_exc = False - while self._exit_callbacks: - cb = self._exit_callbacks.pop() - try: - if cb(*exc_details): - suppressed_exc = True - exc_details = (None, None, None) - except: - new_exc_details = sys.exc_info() - # simulate the stack of exceptions by setting the context - _fix_exception_context(new_exc_details[1], exc_details[1]) - if not self._exit_callbacks: - raise - exc_details = new_exc_details - return suppressed_exc |