This implements (most of) the PEP-498 spec for f-strings and is based on
https://github.com/micropython/micropython/pull/4998 by @klardotsh.
It is implemented in the lexer as a syntax translation to `str.format`:
f"{a}" --> "{}".format(a)
It also supports:
f"{a=}" --> "a={}".format(a)
This is done by extracting the arguments into a temporary vstr buffer,
then after the string has been tokenized, the lexer input queue is saved
and the contents of the temporary vstr buffer are injected into the lexer
instead.
There are four main limitations:
- raw f-strings (`fr` or `rf` prefixes) are not supported and will raise
`SyntaxError: raw f-strings are not supported`.
- literal concatenation of f-strings with adjacent strings will fail
"{}" f"{a}" --> "{}{}".format(a) (str.format will incorrectly use
the braces from the non-f-string)
f"{a}" f"{a}" --> "{}".format(a) "{}".format(a) (cannot concatenate)
- PEP-498 requires the full parser to understand the interpolated
argument, however because this entirely runs in the lexer it cannot
resolve nested braces in expressions like
f"{'}'}"
- The !r, !s, and !a conversions are not supported.
Includes tests and cpydiffs.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Commit cb68a5741a broke automatic Python
feature detection when running tests, because some detection relied on a
crash of a feature script returning exactly b"CRASH".
This commit fixes this and improves the situation by testing for the lack
of a known pass result, rather than an exact failure result.
Signed-off-by: Damien George <damien@micropython.org>
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".
This adds the Python files in the tests/ directory to be formatted with
./tools/codeformat.py. The basics/ subdirectory is excluded for now so we
aren't changing too much at once.
In a few places `# fmt: off`/`# fmt: on` was used where the code had
special formatting for readability or where the test was actually testing
the specific formatting.
This commit adds backward-word, backward-kill-word, forward-word,
forward-kill-word sequences for the REPL, with bindings to Alt+F, Alt+B,
Alt+D and Alt+Backspace respectively. It is disabled by default and can be
enabled via MICROPY_REPL_EMACS_WORDS_MOVE.
Further enabling MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE adds extra bindings
for these new sequences: Ctrl+Right, Ctrl+Left and Ctrl+W.
The features are enabled on unix micropython-coverage and micropython-dev.
MICROPY_LONGINT_IMPL_LONGLONG doesn't have overflow detection, so just
parsing a large number won't give an error, we need to print it out
to check that the whole number was parsed.
If sets are not enabled, set literals lead to SyntaxError during parsing,
so it requires feature_check. Set tests are skipped based on set_*.py
pattern.
Damien George