purescript/maybe segfaults at runtime

[purescript-python]

purescript/maybe segfaults at runtime

[thautwarm]

Diana is yet another goal and not related to purescript python. The new purescript python will be almost compatible to the old.

[thautwarm]

Thanks for this clarified bug report.

I'm sorry that PureScript Python is currently outdated and only works with older purescript compilers and package-sets.

[akazukin5151]

I still get a segfault with an older version of the purescript compiler. Perhaps I need to downgrade spago too?

> purs --version
0.13.6
> spago --version          
0.20.3
> pspy --version
0.8.9

Steps:
(I no longer get the first and second errors in the appendix above)

git clone https://github.com/purescript-python/example-hw
cd example-hw
spago install maybe
# Edit src/Main.purs as above
spago build && pspy --run

Edit: tried with spago version 0.13.1 and it still segfaults

What's the latest version purescript compiler version that's supported by purescript-python?

[thautwarm]

@akazukin5151 What is your Python version? Runtime segfaults seem to be caused by incorrect bytecode generation.

[akazukin5151]

Oh, it's Python 3.9.1. I use conda so I can easily downgrade. What version is supported?

[thautwarm]

Python 3.8 is the maximum supported version. Besides, version 0.13.8 is the latest supported PureScript compiler:

purescript-python/stack.yaml

Line 6 in de37323

- purescript-0.13.8@sha256:c2855514c6f7da4b5f5e3b1020597111d2982b69f460d1c33b7e9f6c9ea8159c,57030

[akazukin5151]

It worked, thanks. We should at least mention the version requirements in the README?

There's still this warning though, but not essential:

/home/twenty/example-hw/example_hw/ffi/Data/Ord.py:22: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  if o is not 0:

[thautwarm]

You are welcome.

We should at least mention the version requirements in the README?

Yes. Maybe you send a PR? I personally do not want to work further on the current implementation -- I'm trying to bump up the compiler and switch to a brand-new implementation that is more maintainable.

There's still this warning though ..

We optimize comparisons for small integers, but Python 3.8 emits "excessive" warnings. To avoid such warnings, you can import your purescript code into python after executing the following statements.

import warnings
warnings.filterwarnings('ignore', category=SyntaxWarning, message='"is" with a literal')

[akazukin5151]

Looking at the new branch, are you going to replace everything related to Python into Diana? Will people be able to continue using the old purescript-python?