Concatenation of f-strings throws syntax error

[peterhinch]

From this forum thread - ignore incorrect title:

x = 1
y = 2
f"{x}" f"{y}"

On CPython this produces 12. On MicroPython Unix build:

MicroPython v1.17 on 2021-09-02; linux version
Use Ctrl-D to exit, Ctrl-E for paste mode
>>> x = 1
>>> y = 2
>>> f"{x}" f"{y}"
Traceback (most recent call last):
  File "<stdin>", line 1
SyntaxError: invalid syntax
>>> 

[dpgeorge]

This is a known limitation of f-strings in MicroPython. It's actually documented: http://docs.micropython.org/en/latest/genrst/core_language.html#f-strings-don-t-support-concatenation-with-adjacent-literals-if-the-adjacent-literals-contain-braces

@jimmo it seems there's a minor issue with that cpydiff, that "aa" f"abc" is not supported in CPy either.

[peterhinch]

Apologies. I hadn't spotted that doc update.