Assignment with list patterns does not work. #459

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lyken · 2024-07-16T11:35:42+08:00

lyken commented

2024-07-16 11:35:42 +08:00

@extern
def output_int32(x: int32):
    ...

def run() -> int32:
    x, [y, z] = 1, [2, 3]
    output_int32(x)
    output_int32(y)
    output_int32(z)
    return 0

Gives the error:

1 error(s) occurred during top level analysis.
=========== ERROR 1/1 ============
type error at identifier `y` (cannot get type of y) at src/_test.py:6:9
==================================

Note that with tuples x, (y, z) = 1, (2, 3), it does work.

This is not easy to support - the codegen part could be very complicated - R.H.S. could contain a list whose length cannot be determined at compile time, this might need an LLVM for loop to assign the elements of the input list to different vars on L.H.S + assertion on the input list's length.

```python @extern def output_int32(x: int32): ... def run() -> int32: x, [y, z] = 1, [2, 3] output_int32(x) output_int32(y) output_int32(z) return 0 ``` Gives the error: ``` 1 error(s) occurred during top level analysis. =========== ERROR 1/1 ============ type error at identifier `y` (cannot get type of y) at src/_test.py:6:9 ================================== ``` Note that with tuples `x, (y, z) = 1, (2, 3)`, it does work. This is not easy to support - the codegen part could be very complicated - R.H.S. could contain a list whose length cannot be determined at compile time, this might need an LLVM for loop to assign the elements of the input list to different vars on L.H.S + assertion on the input list's length.

lyken added the

low-priority

label 2024-07-16 11:35:42 +08:00

lyken changed title from ~~Assignment with list pattern matching does not work.~~ to Assignment with list patterns does not work.

2024-07-16 11:35:54 +08:00

lyken referenced this issue

2024-08-04 21:57:42 +08:00

core: reimplement assignment type inference and codegen + other minor changes & refactor #483

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