circuitpython/tests/cpydiff/syntax_arg_unpacking.py
David Lechner 783b1a868f py/runtime: Allow multiple *args in a function call.
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>
2022-03-31 16:59:30 +11:00

24 lines
678 B
Python

"""
categories: Syntax
description: Argument unpacking does not work if the argument being unpacked is the nth or greater argument where n is the number of bits in an MP_SMALL_INT.
cause: The implementation uses an MP_SMALL_INT to flag args that need to be unpacked.
workaround: Use fewer arguments.
"""
def example(*args):
print(len(args))
MORE = ["a", "b", "c"]
# fmt: off
example(
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
*MORE,
)
# fmt: on