suspect-devices/circuitpython/py, branch 5.2.0

runtime: Improve error message when setting read-only property

2020-03-20T22:57:28+00:00

Formerly, if you wrote SPI.frequency = 0 you would get the sightly erroneous error message AttributeError: 'SPI' object has no attribute 'frequency' In this case, a better message would read AttributeError: 'SPI' object cannot assign attribute 'frequency' This new message will both be used in the case where the attribute doesn't exist at all (and the object has no dynamic attributes; most instances of built in types behave this way), or if the attribute exists but is read-only.

ulab: include new 'extras' source file

2020-03-17T14:33:17+00:00

ulab: rename enable macro so it appears in the support matrix

2020-03-17T14:33:03+00:00

objslice: take mp_obj_slice_indices from micropython

2020-03-17T13:32:52+00:00

Merge pull request #2690 from jepler/topic-pep-498-fstrings

2020-03-10T17:53:04+00:00

Implement partial PEP-498 (f-string) support

circuitpy_mpconfig.mk: Enable ULAB for "full builds"

2020-03-09T20:54:40+00:00

This enables it on the imxrt and cds56 ports where it was disabled before

f-strings: Make optional, defaulting to !CIRCUITPY_MINIMAL_BUILD

2020-03-09T14:03:25+00:00

This should reclaim *most* code space added to handle f-strings. However, there may be some small code growth as parse_string_literal takes a new parameter (which will always be 0, so hopefully the optimizer eliminates it)

lexer: catch concatenation of f'' and '' strings

2020-03-09T14:03:25+00:00

This turns the "edge case" into a parse-time error.

Address dpgeorge feedback - largely simplifications

2020-03-09T13:16:07+00:00

py: Implement partial PEP-498 (f-string) support

2020-03-09T13:16:07+00:00

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](https://github.com/micropython/micropython/commit/534b7c368dc2af7720f3aaed0c936ef46d773957), 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.