micropython/tests/basics/assign_expr_syntaxerror.py

# test SyntaxError with := operator

def test(code):
    try:
        print(eval(code))
    except SyntaxError:
        print('SyntaxError')

test("x := 1")
test("((x, y) := 1)")
test("([i := i + 1 for i in range(4)])")
test("([i := -1 for i, j in [(1, 2)]])")
test("([[(i := j) for i in range(2)] for j in range(2)])")

# this is currently allowed in MicroPython, but not in CPython
test("([[(j := i) for i in range(2)] for j in range(2)])")
tests/basics: Add tests for assignment operator :=. 2020-06-16 12:42:50 +01:00			`# test SyntaxError with := operator`

			`def test(code):`
			`try:`
			`print(eval(code))`
			`except SyntaxError:`
			`print('SyntaxError')`

			`test("x := 1")`
			`test("((x, y) := 1)")`
			`test("([i := i + 1 for i in range(4)])")`
			`test("([i := -1 for i, j in [(1, 2)]])")`
			`test("([[(i := j) for i in range(2)] for j in range(2)])")`
py/compile: Fix scope of assignment expression target in comprehensions. When := is used in a comprehension the target variable is bound to the parent scope, so it's either a global or a nonlocal. Prior to this commit that was handled by simply using the parent scope's id_info for the target variable. That's completely wrong because it uses the slot number for the parent's Python stack to store the variable, rather than the slot number for the comprehension. This will in most cases lead to incorrect behaviour or memory faults. This commit fixes the scoping of the target variable by explicitly declaring it a global or nonlocal, depending on whether the parent is the global scope or not. Then the id_info of the comprehension can be used to access the target variable. This fixes a lot of cases of using := in a comprehension. Code size change for this commit: bare-arm: +0 +0.000% minimal x86: +0 +0.000% unix x64: +152 +0.019% standard stm32: +96 +0.024% PYBV10 cc3200: +96 +0.052% esp8266: +196 +0.028% GENERIC esp32: +156 +0.010% GENERIC[incl +8(data)] mimxrt: +96 +0.027% TEENSY40 renesas-ra: +88 +0.014% RA6M2_EK nrf: +88 +0.048% pca10040 rp2: +104 +0.020% PICO samd: +88 +0.033% ADAFRUIT_ITSYBITSY_M4_EXPRESS Fixes issue #10895. Signed-off-by: Damien George <damien@micropython.org> 2023-03-02 03:56:37 +00:00
			`# this is currently allowed in MicroPython, but not in CPython`
tests/basics: Add tests for assignment operator :=. 2020-06-16 12:42:50 +01:00			`test("([[(j := i) for i in range(2)] for j in range(2)])")`