This is a partial implementation of PEP 448 to allow unpacking multiple
star args in a function or method call.
This is implemented by changing the emitted bytecodes so that both
positional args and star args are stored as positional args. A bitmap is
added to indicate if an argument at a given position is a positional
argument or a star arg.
In the generated code, this new bitmap takes the place of the old star arg.
It is stored as a small int, so this means only the first N arguments can
be star args where N is the number of bits in a small int.
The runtime is modified to interpret this new bytecode format while still
trying to perform as few memory reallocations as possible.
Signed-off-by: David Lechner <david@pybricks.com>
This is a partial implementation of PEP 448 to allow multiple ** unpackings
when calling a function or method.
The compiler is modified to encode the argument as a None: obj key-value
pair (similar to how regular keyword arguments are encoded as str: obj
pairs). The extra object that was pushed on the stack to hold a single **
unpacking object is no longer used and is removed.
The runtime is modified to decode this new format.
Signed-off-by: David Lechner <david@pybricks.com>
This is consistent with the other 'micro' modules and allows implementing
additional features in Python via e.g. micropython-lib's sys.
Note this is a breaking change (not backwards compatible) for ports which
do not enable weak links, as "import sys" must now be replaced with
"import usys".
In Python 3.7 the behaviour of repr() of an exception with one argument
changed: it no longer prints a trailing comma in the argument list. See
https://bugs.python.org/issue30399
This patch modifies tests that rely on this behaviour to not rely on it.
And the python34.py test is updated to include a test for this behaviour
with a .exp file.
In CPython 3.4 this raises a SyntaxError. In CPython 3.5+ having a
positional after * is allowed but uPy has the wrong semantics and passes
the arguments in the incorrect order. To prevent incorrect use of a
function going unnoticed it is important to raise the SyntaxError in uPy,
until the behaviour is fixed to follow CPython 3.5+.
CPython 3.6 has a few changes that, when run on uPy's test suite, give a
different output to CPython 3.5. uPy currently officially supports the
3.4 language definition, but it's useful to be able to run the test suite
with 3.4/3.5/3.6 versions of CPython. This patch makes such changes to
support 3.6.
Jim Mussared