cpython/Doc/c-api/gen.rst

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.. highlight:: c
.. _gen-objects:
Generator Objects
-----------------
Generator objects are what Python uses to implement generator iterators. They
are normally created by iterating over a function that yields values, rather
than explicitly calling :c:func:`PyGen_New` or :c:func:`PyGen_NewWithQualName`.
.. c:type:: PyGenObject
The C structure used for generator objects.
.. c:type:: PySendResult
The enum value used to represent different results of :c:func:`PyGen_Send`.
.. c:var:: PyTypeObject PyGen_Type
The type object corresponding to generator objects.
.. c:function:: int PyGen_Check(PyObject *ob)
Return true if *ob* is a generator object; *ob* must not be ``NULL``.
.. c:function:: int PyGen_CheckExact(PyObject *ob)
Return true if *ob*'s type is :c:type:`PyGen_Type`; *ob* must not be ``NULL``.
.. c:function:: PyObject* PyGen_New(PyFrameObject *frame)
Create and return a new generator object based on the *frame* object.
A reference to *frame* is stolen by this function. The argument must not be
``NULL``.
.. c:function:: PyObject* PyGen_NewWithQualName(PyFrameObject *frame, PyObject *name, PyObject *qualname)
Create and return a new generator object based on the *frame* object,
with ``__name__`` and ``__qualname__`` set to *name* and *qualname*.
A reference to *frame* is stolen by this function. The *frame* argument
must not be ``NULL``.
.. c:function:: PySendResult PyGen_Send(PyGenObject *gen, PyObject *arg, PyObject **presult)
Sends the *arg* value into the generator *gen*. Coroutine objects
are also allowed to be as the *gen* argument but they need to be
explicitly casted to PyGenObject*. Returns:
- ``PYGEN_RETURN`` if generator returns. Return value is returned via *presult*.
- ``PYGEN_NEXT`` if generator yields. Yielded value is returned via *presult*.
- ``PYGEN_ERROR`` if generator has raised and exception. *presult* is set to ``NULL``.