This implements (most of) the PEP-498 spec for f-strings, with two
exceptions:
- raw f-strings (`fr` or `rf` prefixes) raise `NotImplementedError`
- one special corner case does not function as specified in the PEP
(more on that in a moment)
This is implemented in the core as a syntax translation, brute-forcing
all f-strings to run through `String.format`. For example, the statement
`x='world'; print(f'hello {x}')` gets translated *at a syntax level*
(injected into the lexer) to `x='world'; print('hello {}'.format(x))`.
While this may lead to weird column results in tracebacks, it seemed
like the fastest, most efficient, and *likely* most RAM-friendly option,
despite being implemented under the hood with a completely separate
`vstr_t`.
Since [string concatenation of adjacent literals is implemented in the
lexer](534b7c368d),
two side effects emerge:
- All strings with at least one f-string portion are concatenated into a
single literal which *must* be run through `String.format()` wholesale,
and:
- Concatenation of a raw string with interpolation characters with an
f-string will cause `IndexError`/`KeyError`, which is both different
from CPython *and* different from the corner case mentioned in the PEP
(which gave an example of the following:)
```python
x = 10
y = 'hi'
assert ('a' 'b' f'{x}' '{c}' f'str<{y:^4}>' 'd' 'e') == 'ab10{c}str< hi >de'
```
The above-linked commit detailed a pretty solid case for leaving string
concatenation in the lexer rather than putting it in the parser, and
undoing that decision would likely be disproportionately costly on
resources for the sake of a probably-low-impact corner case. An
alternative to become complaint with this corner case of the PEP would
be to revert to string concatenation in the parser *only when an
f-string is part of concatenation*, though I've done no investigation on
the difficulty or costs of doing this.
A decent set of tests is included. I've manually tested this on the
`unix` port on Linux and on a Feather M4 Express (`atmel-samd`) and
things seem sane.
Before this, such names would instead cause an assertion error inside
qstr_from_strn.
A simple reproducer is a python source file containing the letter "a"
repeated 256 times
This string is recognised by uncrustify, to disable formatting in the
region marked by these comments. This is necessary in the qstrdef*.h files
to prevent modification of the strings within the Q(...). In other places
it is used to prevent excessive reformatting that would make the code less
readable.
This only fixes the `import` portion. It doesn't actually change
reference behavior because modules within a package could already
be referenced through the parent package even though an error should
have been thrown.
And rename it to mp_obj_cast_to_native_base() to indicate this. This
allows users of this function to easily support native and native-subclass
objects in the same way (by just passing the object through this function).
Since commit 3aab54bf434e7f025a91ea05052f1bac439fad8c this piece of code is
no longer needed because the top-level function mp_obj_equal_not_equal()
now handles the case of user types, and will never call tuple's binary_op
function with MP_BINARY_OP_EQUAL and a non-tuple on the RHS.
Follow up to recent commit ad7213d3c31bccb26a3f54f7492ccf4b0cc920f3, the
name "varg2" is misleading, vlist describes better that the argument is a
va_list. This name also matches CircuitPython, which already has such
helper functions.
This provides a more consistent C-level API to raise exceptions, ie moving
away from nlr_raise towards mp_raise_XXX. It also reduces code size by a
small amount on some ports.
Both bool and namedtuple will check against other types for equality; int,
float and complex for bool, and tuple for namedtuple. So to make them work
after the recent commit 3aab54bf434e7f025a91ea05052f1bac439fad8c they would
need MP_TYPE_FLAG_NEEDS_FULL_EQ_TEST set. But that makes all bool and
namedtuple equality checks less efficient because mp_obj_equal_not_equal()
could no longer short-cut x==x, and would need to try __ne__. To improve
this, this commit splits the MP_TYPE_FLAG_NEEDS_FULL_EQ_TEST flags into 3
separate flags to give types more fine-grained control over how their
equality behaves. These new flags are then used to fix bool and namedtuple
equality.
Fixes issue #5615 and #5620.
This is a more logical place to clear the KeyboardInterrupt traceback,
right before it is set as a pending exception. The clearing is also
optimised from a function call to a simple store of NULL.
Functions like mp_keyboard_interrupt() may need to be called from an IRQ
handler and may need to be in a special memory section, so provide a
generic wrapping macro for a port to do this. The macro name is chosen to
be MICROPY_WRAP_<function name in uppercase> so that (in the future with
more wrappers) each function could potentially be handled separately.
This function is tightly coupled to the state and behaviour of the
scheduler, and is a core part of the runtime: to schedule a pending
exception. So move it there.
Previous behaviour is when this argument is set to "true", in which case
the function will raise any pending exception. Setting it to "false" will
cancel any pending exception.
A 'return' statement on module/class level is not correct Python, but
nothing terribly bad happens when it's allowed. So remove the check unless
MICROPY_CPYTHON_COMPAT is on.
This is similar to MicroPython's treatment of 'import *' in functions
(except 'return' has unsurprising behavior if it's allowed).
