"Zero cost" exception handling.
* Uses a lookup table to determine how to handle exceptions.
* Removes SETUP_FINALLY and POP_TOP block instructions, eliminating (most of) the runtime overhead of try statements.
* Reduces the size of the frame object by about 60%.
The new syntax is highly human readable while still preventing false
positives. The syntax also extends Python syntax to denote "self" and
positional-only parameters, allowing inspect.Signature objects to be
totally accurate for all supported builtins in Python 3.4.
annotate text signatures in docstrings, resulting in fewer false
positives. "self" parameters are also explicitly marked, allowing
inspect.Signature() to authoritatively detect (and skip) said parameters.
Issue #20326: Argument Clinic now generates separate checksums for the
input and output sections of the block, allowing external tools to verify
that the input has not changed (and thus the output is not out-of-date).
PyMethodDescr_Type, _PyMethodWrapper_Type, and PyWrapperDescr_Type)
have been modified to provide introspection information for builtins.
Also: many additional Lib, test suite, and Argument Clinic fixes.
* You may now specify an expression as the default value for a
parameter! Example: "sys.maxsize - 1". This support is
intentionally quite limited; you may only use values that
can be represented as static C values.
* Removed "doc_default", simplified support for "c_default"
and "py_default". (I'm not sure we still even need
"py_default", but I'm leaving it in for now in case a
use presents itself.)
* Parameter lines support a trailing '\\' as a line
continuation character, allowing you to break up long lines.
* The argument parsing code generated when supporting optional
groups now uses PyTuple_GET_SIZE instead of PyTuple_GetSize,
leading to a 850% speedup in parsing. (Just kidding, this
is an unmeasurable difference.)
* A bugfix for the recent regression where the generated
prototype from pydoc for builtins would be littered with
unreadable "=<object ...>"" default values for parameters
that had no default value.
* Converted some asserts into proper failure messages.
* Many doc improvements and fixes.
