CHANGES.rst 37.5 KB
Newer Older
Stefan Behnel's avatar
Stefan Behnel committed
1 2 3 4
================
Cython Changelog
================

5 6 7 8
=======
Latest
=======

9 10 11
Features added
--------------

12 13 14
* The ``inline`` function modifier is available as a decorator
  ``@cython.inline`` in pure mode.

15 16 17
* When cygdb is run in a virtualenv, it enables the same virtualenv
  inside of the debugger. Patch by Marc Abramowitz.

Stefan Behnel's avatar
Stefan Behnel committed
18 19
* PEP 465: dedicated infix operator for matrix multiplication (A @ B).

Stefan Behnel's avatar
Stefan Behnel committed
20 21 22
* HTML output of annotated code uses Pygments for code highlighting
  and generally received a major overhaul by Matthias Bussonier.

23 24
* The Python expression "2 ** N" was optimised.

25
* Simple support for declaring Python object types in Python signature
Stefan Behnel's avatar
Stefan Behnel committed
26 27
  annotations.  Currently requires setting the compiler directive
  ``annotation_typing=True``.
28

29 30 31
* Added directive use_switch (defaults to True) to optionally enable
  the chained if statement to switch statement optimization.

32 33 34
Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
35 36 37 38
* Names that were unknown at compile time were looked up as builtins at
  runtime but not as global module names.  This helps with globals()
  manipulation.

Stefan Behnel's avatar
Stefan Behnel committed
39 40
* ``obj.pop(x)`` truncated large C integer values of x to ``Py_ssize_t``.

Stefan Behnel's avatar
Stefan Behnel committed
41 42 43
* ``__init__.pyc`` is recognised as marking a package directory
  (in addition to .py, .pyx and .pxd).

Stefan Behnel's avatar
Stefan Behnel committed
44 45 46
* Syntax highlighting in ``cython-mode.el`` for Emacs no longer
  incorrectly highlights keywords found as part of longer names.

47 48 49
Other changes
-------------

Stefan Behnel's avatar
Stefan Behnel committed
50 51
* Removed support for CPython 2.4, 2.5 and 3.1.

52 53 54 55 56 57 58

0.20.2
===================

Features added
--------------

Stefan Behnel's avatar
Stefan Behnel committed
59
* Some optimisations for set/frozenset instantiation.
60

Stefan Behnel's avatar
Stefan Behnel committed
61
* Support for C++ unordered_set and unordered_map.
62

Stefan Behnel's avatar
Stefan Behnel committed
63 64 65
Bugs fixed
----------

66 67 68 69
* Memory leak when extension subtypes add a memory view as attribute
  to those of the parent type without having Python object attributes
  or a user provided dealloc method.

70 71
* Compiler crash on readonly properties in "binding" mode.

72 73
* Auto-encoding with ``c_string_encoding=ascii`` failed in Py3.3.

74 75 76
* Crash when subtyping freelist enabled Cython extension types with
  Python classes that use ``__slots__``.

77 78 79
* Freelist usage is restricted to CPython to avoid problems with other
  Python implementations.

80 81
* Memory leak in memory views when copying overlapping, contiguous slices.

82
* Format checking when requesting non-contiguous buffers from
Stefan Behnel's avatar
Stefan Behnel committed
83
  ``cython.array`` objects was accidentally omitted in Py3.
84

Stefan Behnel's avatar
Stefan Behnel committed
85 86
* C++ destructor calls in extension types could fail to compile in clang.

87 88
* Buffer format validation failed for sequences of strings in structs.

Stefan Behnel's avatar
Stefan Behnel committed
89 90
* Docstrings on extension type attributes in .pxd files were rejected.

91

Robert Bradshaw's avatar
Robert Bradshaw committed
92 93
0.20.1 (2014-02-11)
===================
94 95 96 97

Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
98 99 100
* Build error under recent MacOS-X versions where ``isspace()`` could not be
  resolved by clang.

101 102 103
* List/Tuple literals multiplied by more than one factor were only multiplied
  by the last factor instead of all.

104 105 106
* Lookups of special methods (specifically for context managers) could fail
  in Python <= 2.6/3.1.

107
* Local variables were erroneously appended to the signature introspection
Stefan Behnel's avatar
Stefan Behnel committed
108
  of Cython implemented functions with keyword-only arguments under Python 3.
109

110 111 112 113 114 115 116 117 118 119 120 121 122 123
* In-place assignments to variables with inferred Python builtin/extension
  types could fail with type errors if the result value type was incompatible
  with the type of the previous value.

* The C code generation order of cdef classes, closures, helper code,
  etc. was not deterministic, thus leading to high code churn.

* Type inference could fail to deduce C enum types.

* Type inference could deduce unsafe or inefficient types from integer
  assignments within a mix of inferred Python variables and integer
  variables.


Robert Bradshaw's avatar
Robert Bradshaw committed
124 125 126

0.20 (2014-01-18)
=================
Stefan Behnel's avatar
Stefan Behnel committed
127 128 129 130

Features added
--------------

Stefan Behnel's avatar
Stefan Behnel committed
131 132
* Support for CPython 3.4.

Robert Bradshaw's avatar
Robert Bradshaw committed
133 134
* Support for calling C++ template functions.

135 136
* ``yield`` is supported in ``finally`` clauses.

Stefan Behnel's avatar
Stefan Behnel committed
137
* The C code generated for finally blocks is duplicated for each exit
Stefan Behnel's avatar
Stefan Behnel committed
138
  case to allow for better optimisations by the C compiler.
Stefan Behnel's avatar
Stefan Behnel committed
139 140 141 142 143

* Cython tries to undo the Python optimisationism of assigning a bound
  method to a local variable when it can generate better code for the
  direct call.

Stefan Behnel's avatar
Stefan Behnel committed
144 145
* Constant Python float values are cached.

Stefan Behnel's avatar
Stefan Behnel committed
146 147 148
* String equality comparisons can use faster type specific code in
  more cases than before.

Stefan Behnel's avatar
Stefan Behnel committed
149 150 151
* String/Unicode formatting using the '%' operator uses a faster
  C-API call.

152
* ``bytearray`` has become a known type and supports coercion from and
153 154
  to C strings.  Indexing, slicing and decoding is optimised. Note that
  this may have an impact on existing code due to type inference.
155

156 157
* Using ``cdef basestring stringvar`` and function arguments typed as
  ``basestring`` is now meaningful and allows assigning exactly
Stefan Behnel's avatar
Stefan Behnel committed
158
  ``str`` and ``unicode`` objects, but no subtypes of these types.
159

Stefan Behnel's avatar
Stefan Behnel committed
160 161 162 163 164
* Support for the ``__debug__`` builtin.

* Assertions in Cython compiled modules are disabled if the running
  Python interpreter was started with the "-O" option.

Stefan Behnel's avatar
Stefan Behnel committed
165 166 167 168 169 170 171
* Some types that Cython provides internally, such as functions and
  generators, are now shared across modules if more than one Cython
  implemented module is imported.

* The type inference algorithm works more fine granular by taking the
  results of the control flow analysis into account.

Stefan Behnel's avatar
Stefan Behnel committed
172 173 174
* A new script in ``bin/cythonize`` provides a command line frontend
  to the cythonize() compilation function (including distutils build).

Stefan Behnel's avatar
Stefan Behnel committed
175
* The new extension type decorator ``@cython.no_gc_clear`` prevents
Stefan Behnel's avatar
Stefan Behnel committed
176
  objects from being cleared during cyclic garbage collection, thus
Stefan Behnel's avatar
Stefan Behnel committed
177 178
  making sure that object attributes are kept alive until deallocation.

Stefan Behnel's avatar
Stefan Behnel committed
179
* During cyclic garbage collection, attributes of extension types that
Stefan Behnel's avatar
Stefan Behnel committed
180
  cannot create reference cycles due to their type (e.g. strings) are
Stefan Behnel's avatar
Stefan Behnel committed
181 182
  no longer considered for traversal or clearing.  This can reduce the
  processing overhead when searching for or cleaning up reference cycles.
Stefan Behnel's avatar
Stefan Behnel committed
183

184 185 186
* Package compilation (i.e. ``__init__.py`` files) now works, starting
  with Python 3.3.

Stefan Behnel's avatar
Stefan Behnel committed
187
* The cython-mode.el script for Emacs was updated.  Patch by Ivan Andrus.
Stefan Behnel's avatar
Stefan Behnel committed
188

189 190 191 192
* An option common_utility_include_dir was added to cythonize() to save
  oft-used utility code once in a separate directory rather than as
  part of each generated file.

Robert Bradshaw's avatar
Robert Bradshaw committed
193 194 195
* ``unraisable_tracebacks`` directive added to control printing of
  tracebacks of unraisable exceptions.

Stefan Behnel's avatar
Stefan Behnel committed
196 197 198
Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
199 200 201 202
* Abstract Python classes that subtyped a Cython extension type
  failed to raise an exception on instantiation, and thus ended
  up being instantiated.

Stefan Behnel's avatar
Stefan Behnel committed
203 204 205
* ``set.add(a_tuple)`` and ``set.discard(a_tuple)`` failed with a
  TypeError in Py2.4.

206 207 208
* The PEP 3155 ``__qualname__`` was incorrect for nested classes and
  inner classes/functions declared as ``global``.

209 210
* Several corner cases in the try-finally statement were fixed.

211 212 213 214 215 216 217 218 219 220
* The metaclass of a Python class was not inherited from its parent
  class(es).  It is now extracted from the list of base classes if not
  provided explicitly using the Py3 ``metaclass`` keyword argument.
  In Py2 compilation mode, a ``__metaclass__`` entry in the class
  dict will still take precedence if not using Py3 metaclass syntax,
  but only *after* creating the class dict (which may have been done
  by a metaclass of a base class, see PEP 3115).  It is generally
  recommended to use the explicit Py3 syntax to define metaclasses
  for Python types at compile time.

Stefan Behnel's avatar
Stefan Behnel committed
221 222 223 224 225 226
* The automatic C switch statement generation behaves more safely for
  heterogeneous value types (e.g. mixing enum and char), allowing for
  a slightly wider application and reducing corner cases.  It now always
  generates a 'default' clause to avoid C compiler warnings about
  unmatched enum values.

Robert Bradshaw's avatar
Robert Bradshaw committed
227 228 229
* Fixed a bug where class hierarchies declared out-of-order could result
  in broken generated code.

Robert Bradshaw's avatar
Robert Bradshaw committed
230 231
* Fixed a bug which prevented overriding const methods of C++ classes.

232 233
* Fixed a crash when converting Python objects to C++ strings fails.

Stefan Behnel's avatar
Stefan Behnel committed
234 235 236
Other changes
-------------

237 238 239
* In Py3 compilation mode, Python2-style metaclasses declared by a
  ``__metaclass__`` class dict entry are ignored.

Stefan Behnel's avatar
Stefan Behnel committed
240 241
* In Py3.4+, the Cython generator type uses ``tp_finalize()`` for safer
  cleanup instead of ``tp_del()``.
Stefan Behnel's avatar
Stefan Behnel committed
242

Stefan Behnel's avatar
Stefan Behnel committed
243

Stefan Behnel's avatar
Stefan Behnel committed
244
0.19.2 (2013-10-13)
Stefan Behnel's avatar
Stefan Behnel committed
245 246 247 248 249 250 251 252
===================

Features added
--------------

Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
253 254 255 256 257 258 259
* Some standard declarations were fixed or updated, including the previously
  incorrect declaration of ``PyBuffer_FillInfo()`` and some missing bits in
  ``libc.math``.

* Heap allocated subtypes of ``type`` used the wrong base type struct at the
  C level.

Stefan Behnel's avatar
Stefan Behnel committed
260 261 262
* Calling the unbound method dict.keys/value/items() in dict subtypes could
  call the bound object method instead of the unbound supertype method.

Stefan Behnel's avatar
Stefan Behnel committed
263 264 265 266 267 268 269
* "yield" wasn't supported in "return" value expressions.

* Using the "bint" type in memory views lead to unexpected results.
  It is now an error.

* Assignments to global/closure variables could catch them in an illegal state
  while deallocating the old value.
Stefan Behnel's avatar
Stefan Behnel committed
270 271 272 273 274

Other changes
-------------


Stefan Behnel's avatar
Stefan Behnel committed
275
0.19.1 (2013-05-11)
Stefan Behnel's avatar
Stefan Behnel committed
276 277 278 279 280
===================

Features added
--------------

Stefan Behnel's avatar
Stefan Behnel committed
281
* Completely empty C-API structs for extension type slots (protocols like
Stefan Behnel's avatar
Stefan Behnel committed
282
  number/mapping/sequence) are no longer generated into the C code.
Stefan Behnel's avatar
Stefan Behnel committed
283

Stefan Behnel's avatar
Stefan Behnel committed
284 285
* Docstrings that directly follow a public/readonly attribute declaration
  in a cdef class will be used as docstring of the auto-generated property.
Stefan Behnel's avatar
Stefan Behnel committed
286
  This fixes ticket 206.
Stefan Behnel's avatar
Stefan Behnel committed
287 288 289

* The automatic signature documentation tries to preserve more semantics
  of default arguments and argument types.  Specifically, ``bint`` arguments
Stefan Behnel's avatar
Stefan Behnel committed
290
  now appear as type ``bool``.
Stefan Behnel's avatar
Stefan Behnel committed
291

Stefan Behnel's avatar
Stefan Behnel committed
292 293 294 295 296 297 298
* A warning is emitted when negative literal indices are found inside of
  a code section that disables ``wraparound`` handling.  This helps with
  fixing invalid code that might fail in the face of future compiler
  optimisations.

* Constant folding for boolean expressions (and/or) was improved.

Robert Bradshaw's avatar
Robert Bradshaw committed
299 300 301
* Added a build_dir option to cythonize() which allows one to place
  the generated .c files outside the source tree.

Stefan Behnel's avatar
Stefan Behnel committed
302 303 304
Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
305 306 307
* ``isinstance(X, type)`` failed to get optimised into a call to
  ``PyType_Check()``, as done for other builtin types.

308 309 310 311 312 313 314
* A spurious "from datetime cimport *" was removed from the "cpython"
  declaration package. This means that the "datetime" declarations
  (added in 0.19) are no longer available directly from the "cpython"
  namespace, but only from "cpython.datetime". This is the correct
  way of doing it because the declarations refer to a standard library
  module, not the core CPython C-API itself.

Stefan Behnel's avatar
Stefan Behnel committed
315 316 317 318
* The C code for extension types is now generated in topological order
  instead of source code order to avoid C compiler errors about missing
  declarations for subtypes that are defined before their parent.

Stefan Behnel's avatar
Stefan Behnel committed
319 320 321
* The ``memoryview`` type name no longer shows up in the module dict of
  modules that use memory views.  This fixes trac ticket 775.

Stefan Behnel's avatar
Stefan Behnel committed
322 323 324
* Regression in 0.19 that rejected valid C expressions from being used
  in C array size declarations.

Stefan Behnel's avatar
Stefan Behnel committed
325 326 327 328 329 330 331 332 333 334 335
* In C++ mode, the C99-only keyword ``restrict`` could accidentally be
  seen by the GNU C++ compiler. It is now specially handled for both
  GCC and MSVC.

* Testing large (> int) C integer values for their truth value could fail
  due to integer wrap-around.

Other changes
-------------


Stefan Behnel's avatar
Stefan Behnel committed
336
0.19 (2013-04-19)
Stefan Behnel's avatar
Stefan Behnel committed
337 338 339 340 341
=================

Features added
--------------

Stefan Behnel's avatar
Stefan Behnel committed
342 343 344 345
* New directives ``c_string_type`` and ``c_string_encoding`` to more easily
  and automatically convert between C strings and the different Python string
  types.

346 347 348 349
* The extension type flag ``Py_TPFLAGS_HAVE_VERSION_TAG`` is enabled by default
  on extension types and can be disabled using the ``type_version_tag`` compiler
  directive.

350 351 352
* EXPERIMENTAL support for simple Cython code level line tracing.  Enabled by
  the "linetrace" compiler directive.

353 354 355
* Cython implemented functions make their argument and return type annotations
  available through the ``__annotations__`` attribute (PEP 3107).

Stefan Behnel's avatar
Stefan Behnel committed
356 357 358 359 360 361 362
* Access to non-cdef module globals and Python object attributes is faster.

* ``Py_UNICODE*`` coerces from and to Python unicode strings.  This is
  helpful when talking to Windows APIs, which use compatible wchar_t
  arrays for strings.  Note that the ``Py_UNICODE`` type is otherwise
  deprecated as of CPython 3.3.

363 364 365 366 367 368
* ``isinstance(obj, basestring)`` is optimised.  In Python 3 it only tests
  for instances of ``str`` (i.e. Py2 ``unicode``).

* The ``basestring`` builtin is mapped to ``str`` (i.e. Py2 ``unicode``) when
  compiling the generated C code under Python 3.

Stefan Behnel's avatar
Stefan Behnel committed
369 370 371
* Closures use freelists, which can speed up their creation quite substantially.
  This is also visible for short running generator expressions, for example.

Stefan Behnel's avatar
Stefan Behnel committed
372 373 374
* A new class decorator ``@cython.freelist(N)`` creates a static freelist of N
  instances for an extension type, thus avoiding the costly allocation step if
  possible. This can speed up object instantiation by 20-30% in suitable
Stefan Behnel's avatar
Stefan Behnel committed
375 376
  scenarios. Note that freelists are currently only supported for base types,
  not for types that inherit from others.
Stefan Behnel's avatar
Stefan Behnel committed
377

Stefan Behnel's avatar
Stefan Behnel committed
378 379 380 381
* Fast extension type instantiation using the ``Type.__new__(Type)`` idiom has
  gained support for passing arguments.  It is also a bit faster for types defined
  inside of the module.

382 383 384 385
* The Python2-only dict methods ``.iter*()`` and ``.view*()`` (requires Python 2.7)
  are automatically mapped to the equivalent keys/values/items methods in Python 3
  for typed dictionaries.

Stefan Behnel's avatar
Stefan Behnel committed
386
* Slicing unicode strings, lists and tuples is faster.
Stefan Behnel's avatar
Stefan Behnel committed
387

Stefan Behnel's avatar
Stefan Behnel committed
388 389
* list.append() is faster on average.

Stefan Behnel's avatar
Stefan Behnel committed
390 391
* ``raise Exception() from None`` suppresses the exception context in Py3.3.

Stefan Behnel's avatar
Stefan Behnel committed
392 393
* Py3 compatible ``exec(tuple)`` syntax is supported in Py2 code.

Stefan Behnel's avatar
Stefan Behnel committed
394 395
* Keyword arguments are supported for cdef functions.

Stefan Behnel's avatar
Stefan Behnel committed
396 397
* External C++ classes can be declared nogil.  Patch by John Stumpo.  This fixes
  trac ticket 805.
398

Stefan Behnel's avatar
Stefan Behnel committed
399 400 401
Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
402 403 404 405 406
* 2-value slicing of unknown objects passes the correct slice when the ``getitem``
  protocol is used instead of the ``getslice`` protocol (especially in Python 3),
  i.e. ``None`` values for missing bounds instead of ``[0,maxsize]``.  It is also
  a bit faster in some cases, e.g. for constant bounds.  This fixes trac ticket 636.

Stefan Behnel's avatar
Stefan Behnel committed
407 408 409
* Cascaded assignments of None values to extension type variables failed with
  a ``TypeError`` at runtime.

410 411 412 413 414 415 416
* The ``__defaults__`` attribute was not writable for Cython implemented
  functions.

* Default values of keyword-only arguments showed up in ``__defaults__`` instead
  of ``__kwdefaults__`` (which was not implemented).  Both are available for
  Cython implemented functions now, as specified in Python 3.x.

Stefan Behnel's avatar
Stefan Behnel committed
417 418 419 420 421 422
* ``yield`` works inside of ``with gil`` sections.  It previously lead to a crash.
  This fixes trac ticket 803.

* Static methods without explicitly named positional arguments (e.g. having only
  ``*args``) crashed when being called.  This fixes trac ticket 804.

Stefan Behnel's avatar
Stefan Behnel committed
423 424 425
* ``dir()`` without arguments previously returned an unsorted list, which now
  gets sorted as expected.

Stefan Behnel's avatar
Stefan Behnel committed
426 427 428
* ``dict.items()``, ``dict.keys()`` and ``dict.values()`` no longer return lists
  in Python 3.

Stefan Behnel's avatar
Stefan Behnel committed
429 430
* Exiting from an ``except-as`` clause now deletes the exception in Python 3 mode.

Stefan Behnel's avatar
Stefan Behnel committed
431 432 433 434 435 436
* The declarations of ``frexp()`` and ``ldexp()`` in ``math.pxd`` were incorrect.

Other changes
-------------


Stefan Behnel's avatar
Stefan Behnel committed
437 438
0.18 (2013-01-28)
=================
439 440 441 442

Features added
--------------

443 444
* Named Unicode escapes ("\N{...}") are supported.

445 446 447
* Python functions/classes provide the special attribute "__qualname__"
  as defined by PEP 3155.

448 449 450 451
* Added a directive ``overflowcheck`` which raises an OverflowException when
  arithmetic with C ints overflow.  This has a modest performance penalty, but
  is much faster than using Python ints.

Stefan Behnel's avatar
Stefan Behnel committed
452 453 454 455
* Calls to nested Python functions are resolved at compile time.

* Type inference works across nested functions.

Stefan Behnel's avatar
Stefan Behnel committed
456 457
* ``py_bytes_string.decode(...)`` is optimised.

Stefan Behnel's avatar
Stefan Behnel committed
458 459
* C ``const`` declarations are supported in the language.

460 461 462
Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
463 464 465
* Automatic C++ exception mapping didn't work in nogil functions (only in
  "with nogil" blocks).

466 467 468 469
Other changes
-------------


Robert Bradshaw's avatar
Robert Bradshaw committed
470 471 472 473 474 475 476 477 478
0.17.4 (2013-01-03)
===================

Bugs fixed
----------

* Garbage collection triggered during deallocation of container classes could lead to a double-deallocation.


Stefan Behnel's avatar
Stefan Behnel committed
479
0.17.3 (2012-12-14)
Stefan Behnel's avatar
Stefan Behnel committed
480 481 482 483 484 485 486 487
===================

Features added
--------------

Bugs fixed
----------

488 489
* During final interpreter cleanup (with types cleanup enabled at compile time), extension types that inherit from base types over more than one level that were cimported from other modules could lead to a crash.

Stefan Behnel's avatar
Stefan Behnel committed
490 491
* Weak-reference support in extension types (with a ``cdef __weakref__`` attribute) generated incorrect deallocation code.

Stefan Behnel's avatar
Stefan Behnel committed
492 493
* In CPython 3.3, converting a Unicode character to the Py_UNICODE type could fail to raise an overflow for non-BMP characters that do not fit into a wchar_t on the current platform.

Stefan Behnel's avatar
Stefan Behnel committed
494 495 496 497 498 499
* Negative C integer constants lost their longness suffix in the generated C code.

Other changes
-------------


Stefan Behnel's avatar
Stefan Behnel committed
500
0.17.2 (2012-11-20)
Stefan Behnel's avatar
Stefan Behnel committed
501 502 503 504 505 506 507 508 509 510
===================

Features added
--------------

* ``cythonize()`` gained a best effort compile mode that can be used to simply ignore .py files that fail to compile.

Bugs fixed
----------

Stefan Behnel's avatar
Stefan Behnel committed
511 512
* Replacing an object reference with the value of one of its cdef attributes could generate incorrect C code that accessed the object after deleting its last reference.

Stefan Behnel's avatar
Stefan Behnel committed
513 514
* C-to-Python type coercions during cascaded comparisons could generate invalid C code, specifically when using the 'in' operator.

515 516
* "obj[1,]" passed a single integer into the item getter instead of a tuple.

Stefan Behnel's avatar
Stefan Behnel committed
517 518 519 520 521 522 523 524 525 526 527 528
* Cyclic imports at module init time did not work in Py3.

* The names of C++ destructors for template classes were built incorrectly.

* In pure mode, type casts in Cython syntax and the C ampersand operator are now rejected. Use the pure mode replacements instead.

* In pure mode, C type names and the sizeof() function are no longer recognised as such and can be used as normal Python names.

* The extended C level support for the CPython array type was declared too late to be used by user defined classes.

* C++ class nesting was broken.

529 530 531 532 533 534 535 536
* Better checking for required nullary constructors for stack-allocated C++ instances.

* Remove module docstring in no-docstring mode.

* Fix specialization for varargs function signatures.

* Fix several compiler crashes.

Stefan Behnel's avatar
Stefan Behnel committed
537 538 539
Other changes
-------------

Stefan Behnel's avatar
Stefan Behnel committed
540 541
* An experimental distutils script for compiling the CPython standard library was added as Tools/cystdlib.py.

Stefan Behnel's avatar
Stefan Behnel committed
542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565

0.17.1 (2012-09-26)
===================

Features added
--------------

Bugs fixed
----------

* A reference leak was fixed in the new dict iteration code when the loop target was not a plain variable but an unpacked tuple.

* Memory views did not handle the special case of a NULL buffer strides value, as allowed by PEP3118.

Other changes
-------------


0.17 (2012-09-01)
=================

Features added
--------------

Stefan Behnel's avatar
Stefan Behnel committed
566
* Alpha quality support for compiling and running Cython generated extension modules in PyPy (through cpyext). Note that this requires at least PyPy 1.9 and in many cases also adaptations in user code, especially to avoid borrowed references when no owned reference is being held directly in C space (a reference in a Python list or dict is not enough, for example). See the documentation on porting Cython code to PyPy.
Stefan Behnel's avatar
Stefan Behnel committed
567 568 569

* "yield from" is supported (PEP 380) and a couple of minor problems with generators were fixed.

Stefan Behnel's avatar
Stefan Behnel committed
570
* C++ STL container classes automatically coerce from and to the equivalent Python container types on typed assignments and casts. Note that the data in the containers is copied during this conversion.
Stefan Behnel's avatar
Stefan Behnel committed
571

Stefan Behnel's avatar
Stefan Behnel committed
572
* C++ iterators can now be iterated over using "for x in cpp_container" whenever cpp_container has begin() and end() methods returning objects satisfying the iterator pattern (that is, it can be incremented, dereferenced, and compared (for non-equality)).
Stefan Behnel's avatar
Stefan Behnel committed
573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596

* cdef classes can now have C++ class members (provided a zero-argument constructor exists)

* A new cpython.array standard cimport file allows to efficiently talk to the stdlib array.array data type in Python 2. Since CPython does not export an official C-API for this module, it receives special casing by the compiler in order to avoid setup overhead on user side. In Python 3, both buffers and memory views on the array type already worked out of the box with earlier versions of Cython due to the native support for the buffer interface in the Py3 array module.

* Fast dict iteration is now enabled optimistically also for untyped variables when the common iteration methods are used.

* The unicode string processing code was adapted for the upcoming CPython 3.3 (PEP 393, new Unicode buffer layout).

* Buffer arguments and memory view arguments in Python functions can be declared "not None" to raise a TypeError on None input.

* c(p)def functions in pure mode can specify their return type with "@cython.returns()".

* Automatic dispatch for fused functions with memoryview arguments

* Support newaxis indexing for memoryviews

* Support decorators for fused functions

Bugs fixed
----------

* Old-style Py2 imports did not work reliably in Python 3.x and were broken in Python 3.3. Regardless of this fix, it's generally best to be explicit about relative and global imports in Cython code because old-style imports have a higher overhead. To this end, "from __future__ import absolute_import" is supported in Python/Cython 2.x code now (previous versions of Cython already used it when compiling Python 3 code).

Stefan Behnel's avatar
Stefan Behnel committed
597
* Stricter constraints on the "inline" and "final" modifiers. If your code does not compile due to this change, chances are these modifiers were previously being ignored by the compiler and can be removed without any performance regression.
Stefan Behnel's avatar
Stefan Behnel committed
598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961

* Exceptions are always instantiated while raising them (as in Python), instead of risking to instantiate them in potentially unsafe situations when they need to be handled or otherwise processed.

* locals() properly ignores names that do not have Python compatible types (including automatically inferred types).

* Some garbage collection issues of memory views were fixed.

* numpy.pxd compiles in Python 3 mode.

* Several C compiler warnings were fixed.

* Several bugs related to memoryviews and fused types were fixed.

* Several bug-fixes and improvements related to cythonize(), including ccache-style caching.

Other changes
-------------

* libc.string provides a convenience declaration for const uchar in addition to const char.

* User declared char* types are now recognised as such and auto-coerce to and from Python bytes strings.

* callable() and next() compile to more efficient C code.

* list.append() is faster on average.

* Modules generated by @cython.inline() are written into the directory pointed to by the environment variable CYTHON_CACHE_DIR if set.


0.16 (2012-04-21)
=================

Features added
--------------

* Enhancements to Cython's function type (support for weak references, default arguments, code objects, dynamic attributes, classmethods, staticmethods, and more)

* Fused Types - Template-like support for functions and methods CEP 522 (docs)

* Typed views on memory - Support for efficient direct and indirect buffers (indexing, slicing, transposing, ...) CEP 517 (docs)

* super() without arguments

* Final cdef methods (which translate into direct calls on known instances)

Bugs fixed
----------

* fix alignment handling for record types in buffer support

Other changes
-------------

* support default arguments for closures

* search sys.path for pxd files

* support C++ template casting

* faster traceback building and faster generator termination

* support inplace operators on indexed buffers

* allow nested prange sections


0.15.1 (2011-09-19)
===================

Features added
--------------

Bugs fixed
----------

Other changes
-------------


0.15 (2011-08-05)
=================

Features added
--------------

* Generators (yield) - Cython has full support for generators, generator expressions and PEP 342 coroutines.

* The nonlocal keyword is supported.

* Re-acquiring the gil: with gil - works as expected within a nogil context.

* OpenMP support: prange.

* Control flow analysis prunes dead code and emits warnings and errors about uninitialised variables.

* Debugger command cy set to assign values of expressions to Cython variables and cy exec counterpart $cy_eval().

* Exception chaining PEP 3134.

* Relative imports PEP 328.

* Improved pure syntax including cython.cclass, cython.cfunc, and cython.ccall.

* The with statement has its own dedicated and faster C implementation.

* Support for del.

* Boundschecking directives implemented for builtin Python sequence types.

* Several updates and additions to the shipped standard library .pxd files.

* Forward declaration of types is no longer required for circular references.

Bugs fixed
----------

Other changes
-------------

* Uninitialized variables are no longer initialized to None and accessing them has the same semantics as standard Python.

* globals() now returns a read-only dict of the Cython module's globals, rather than the globals of the first non-Cython module in the stack

* Many C++ exceptions are now special cased to give closer Python counterparts. This means that except+ functions that formerly raised generic RuntimeErrors may raise something else such as ArithmeticError.

* The inlined generator expressions (introduced in Cython 0.13) were disabled in favour of full generator expression support. This breaks code that previously used them inside of cdef functions (usage in def functions continues to work) and induces a performance regression for cases that continue to work but that were previously inlined. We hope to reinstate this feature in the near future.


0.14.1 (2011-02-04)
===================

Features added
--------------

* The gdb debugging support was extended to include all major Cython features, including closures.

* raise MemoryError() is now safe to use as Cython replaces it with the correct C-API call.

Bugs fixed
----------

Other changes
-------------

* Decorators on special methods of cdef classes now raise a compile time error rather than being ignored.

* In Python 3 language level mode (-3 option), the 'str' type is now mapped to 'unicode', so that cdef str s declares a Unicode string even when running in Python 2.


0.14 (2010-12-14)
=================

Features added
--------------

* Python classes can now be nested and receive a proper closure at definition time.

* Redefinition is supported for Python functions, even within the same scope.

* Lambda expressions are supported in class bodies and at the module level.

* Metaclasses are supported for Python classes, both in Python 2 and Python 3 syntax. The Python 3 syntax (using a keyword argument in the type declaration) is preferred and optimised at compile time.

* "final" extension classes prevent inheritance in Python space. This feature is available through the new "cython.final" decorator. In the future, these classes may receive further optimisations.

* "internal" extension classes do not show up in the module dictionary. This feature is available through the new "cython.internal" decorator.

* Extension type inheritance from builtin types, such as "cdef class MyUnicode(unicode)", now works without further external type redeclarations (which are also strongly discouraged now and continue to issue a warning).

* GDB support. http://docs.cython.org/src/userguide/debugging.html

* A new build system with support for inline distutils directives, correct dependency tracking, and parallel compilation. http://wiki.cython.org/enhancements/distutils_preprocessing

* Support for dynamic compilation at runtime via the new cython.inline function and cython.compile decorator. http://wiki.cython.org/enhancements/inline

* "nogil" blocks are supported when compiling pure Python code by writing "with cython.nogil".

* Iterating over arbitrary pointer types is now supported, as is an optimized version of the in operator, e.g. x in ptr[a:b].

Bugs fixed
----------

* In parallel assignments, the right side was evaluated in reverse order in 0.13. This could result in errors if it had side effects (e.g. function calls).

* In some cases, methods of builtin types would raise a SystemError instead of an AttributeError when called on None.

Other changes
-------------

* Constant tuples are now cached over the lifetime of an extension module, just like CPython does. Constant argument tuples of Python function calls are also cached.

* Closures have tightened to include exactly the names used in the inner functions and classes. Previously, they held the complete locals of the defining function.

* The builtin "next()" function in Python 2.6 and later is now implemented internally and therefore available in all Python versions. This makes it the preferred and portable way of manually advancing an iterator.

* In addition to the previously supported inlined generator expressions in 0.13, "sorted(genexpr)" can now be used as well. Typing issues were fixed in "sum(genexpr)" that could lead to invalid C code being generated. Other known issues with inlined generator expressions were also fixed that make upgrading to 0.14 a strong recommendation for code that uses them. Note that general generators and generator expressions continue to be not supported.

* Inplace arithmetic operators now respect the cdivision directive and are supported for complex types.

* Typing a variable as type "complex" previously gave it the Python object type. It now uses the appropriate C/C++ double complex type. A side-effect is that assignments and typed function parameters now accept anything that Python can coerce to a complex, including integers and floats, and not only complex instances.

* Large integer literals pass through the compiler in a safer way. To prevent truncation in C code, non 32-bit literals are turned into Python objects if not used in a C context. This context can either be given by a clear C literal suffix such as "UL" or "LL" (or "L" in Python 3 code), or it can be an assignment to a typed variable or a typed function argument, in which case it is up to the user to take care of a sufficiently large value space of the target.

* Python functions are declared in the order they appear in the file, rather than all being created at module creation time. This is consistent with Python and needed to support, for example, conditional or repeated declarations of functions. In the face of circular imports this may cause code to break, so a new --disable-function-redefinition flag was added to revert to the old behavior. This flag will be removed in a future release, so should only be used as a stopgap until old code can be fixed.


0.13 (2010-08-25)
=================

Features added
--------------

* Closures are fully supported for Python functions. Cython supports inner functions and lambda expressions. Generators and generator expressions are not supported in this release.

* Proper C++ support. Cython knows about C++ classes, templates and overloaded function signatures, so that Cython code can interact with them in a straight forward way.

* Type inference is enabled by default for safe C types (e.g. double, bint, C++ classes) and known extension types. This reduces the need for explicit type declarations and can improve the performance of untyped code in some cases. There is also a verbose compile mode for testing the impact on user code.

* Cython's for-in-loop can iterate over C arrays and sliced pointers. The type of the loop variable will be inferred automatically in this case.

* The Py_UNICODE integer type for Unicode code points is fully supported, including for-loops and 'in' tests on unicode strings. It coerces from and to single character unicode strings. Note that untyped for-loop variables will automatically be inferred as Py_UNICODE when iterating over a unicode string. In most cases, this will be much more efficient than yielding sliced string objects, but can also have a negative performance impact when the variable is used in a Python context multiple times, so that it needs to coerce to a unicode string object more than once. If this happens, typing the loop variable as unicode or object will help.

* The built-in functions any(), all(), sum(), list(), set() and dict() are inlined as plain for loops when called on generator expressions. Note that generator expressions are not generally supported apart from this feature. Also, tuple(genexpr) is not currently supported - use tuple([listcomp]) instead.

* More shipped standard library declarations. The python_* and stdlib/stdio .pxd files have been deprecated in favor of clib.* and cpython[.*] and may get removed in a future release.

* Pure Python mode no longer disallows non-Python keywords like 'cdef', 'include' or 'cimport'. It also no longer recognises syntax extensions like the for-from loop.

* Parsing has improved for Python 3 syntax in Python code, although not all features are correctly supported. The missing Python 3 features are being worked on for the next release.

* from __future__ import print_function is supported in Python 2.6 and later. Note that there is currently no emulation for earlier Python versions, so code that uses print() with this future import will require at least Python 2.6.

* New compiler directive language_level (valid values: 2 or 3) with corresponding command line options -2 and -3 requests source code compatibility with Python 2.x or Python 3.x respectively. Language level 3 currently enforces unicode literals for unprefixed string literals, enables the print function (requires Python 2.6 or later) and keeps loop variables in list comprehensions from leaking.

* Loop variables in set/dict comprehensions no longer leak into the surrounding scope (following Python 2.7). List comprehensions are unchanged in language level 2.

* print >> stream

Bugs fixed
----------

Other changes
-------------

* The availability of type inference by default means that Cython will also infer the type of pointers on assignments. Previously, code like this::

     cdef char* s = ...
     untyped_variable = s

  would convert the char* to a Python bytes string and assign that. This is no longer the case and no coercion will happen in the example above. The correct way of doing this is through an explicit cast or by typing the target variable, i.e.

  ::

     cdef char* s = ...
     untyped_variable1 = <bytes>s
     untyped_variable2 = <object>s

     cdef object py_object = s
     cdef bytes  bytes_string = s

* bool is no longer a valid type name by default. The problem is that it's not clear whether bool should refer to the Python type or the C++ type, and expecting one and finding the other has already led to several hard-to-find bugs. Both types are available for importing: you can use from cpython cimport bool for the Python bool type, and from libcpp cimport bool for the C++ type. bool is still a valid object by default, so one can still write bool(x).

* ``__getsegcount__`` is now correctly typed to take a ``Py_size_t*`` rather than an ``int*``.


0.12.1 (2010-02-02)
===================

Features added
--------------

* Type inference improvements.

  * There have been several bug fixes and improvements to the type inferencer.

  * Notably, there is now a "safe" mode enabled by setting the infer_types directive to None. (The None here refers to the "default" mode, which will be the default in 0.13.) This safe mode limits inference to Python object types and C doubles, which should speed up execution without affecting any semantics such as integer overflow behavior like infer_types=True might. There is also an infer_types.verbose option which allows one to see what types are inferred.

* The boundscheck directive works for lists and tuples as well as buffers.

* len(s) and s.decode("encoding") are efficiently supported for char* s.

* Cython's INLINE macro has been renamed to CYTHON_INLINE to reduce conflict and has better support for the MSVC compiler on Windows. It is no longer clobbered if externally defined.

* Revision history is now omitted from the source package, resulting in a 85% size reduction. Running make repo will download the history and turn the directory into a complete Mercurial working repository.

* Cython modules don't need to be recompiled when the size of an external type grows. (A warning, rather than an error, is produced.) This should be helpful for binary distributions relying on NumPy.

Bugs fixed
----------

* Several other bugs and minor improvements have been made. This release should be fully backwards compatible with 0.12.

Other changes
-------------


0.12 (2009-11-23)
=================

Features added
--------------

* Type inference with the infer_types directive

* Seamless C++ complex support

* Fast extension type instantiation using the normal Python meme obj = MyType.__new__(MyType)

* Improved support for Py3.1

* Cython now runs under Python 3.x using the 2to3 tool

* unittest support for doctests in Cython modules

* Optimised handling of C strings (char*): for c in cstring[2:50] and cstring.decode()

* Looping over c pointers: for i in intptr[:50].

* pyximport improvements

* cython_freeze improvements

Bugs fixed
----------

* Many bug fixes

Other changes
-------------

* Many other optimisation, e.g. enumerate() loops, parallel swap assignments (a,b = b,a), and unicode.encode()

* More complete numpy.pxd


0.11.2 (2009-05-20)
===================

Features added
--------------

* There's now native complex floating point support! C99 complex will be used if complex.h is included, otherwise explicit complex arithmetic working on all C compilers is used. [Robert Bradshaw]

  ::

      cdef double complex a = 1 + 0.3j
      cdef np.ndarray[np.complex128_t, ndim=2] arr = \
         np.zeros(10, np.complex128)

* Cython can now generate a main()-method for embedding of the Python interpreter into an executable (see #289) [Robert Bradshaw]

* @wraparound directive (another way to disable arr[idx] for negative idx) [Dag Sverre Seljebotn]

* Correct support for NumPy record dtypes with different alignments, and "cdef packed struct" support [Dag Sverre Seljebotn]

* @callspec directive, allowing custom calling convention macros [Lisandro Dalcin]

Bugs fixed
----------

Other changes
-------------

* Bug fixes and smaller improvements. For the full list, see [1].