[Yap-users] Can't read output of a process with pipe

[Gökhan S. <so...@it...>]

Hello,

I want to run a python process from my prolog script (YAP-6.2.2) and read
its output formatted as a list of integers, e.g. [1,2,3,4,5,6].

This is what I do:

:- use_module(library(process)).

:-  process_create(path(python3),
    ['my_script.py'],
    [stdout(pipe(Out))]),
read(Out, OutputList),
close(Out).

However, it fails at read/2 predicate with the error:

PL_unify_term: PL_int64 not supported
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w'
encoding='UTF-8'>
BrokenPipeError: [Errno 32] Broken pipe

I am sure that I can run the process correctly because with [stdout(std)]
parameter given to process_create the program outputs [1,2,3,4,5,6] as
expected.

Weird thing is that when I change the process to output some constant_term
it still gives the same PL_int64 error. Appending a dot to the process'
output ([1,2,3,4,5,6].) doesn't solve the error. Using read_term/3 gives
the same error.

How can I solve this problem?

This question is also asked here
<http://stackoverflow.com/questions/43029488/read-a-list-from-stream-using-yap-prolog>
.

Thanks in advance,
Gökhan Solak