unload_file behavior differs from prolog. #85
Description
It seems I can use pyswip to load a .pl, but not unload one: [update]
from pyswip import Prolog
prolog = Prolog()
filename = "f" # # f.pl contains just foo(1,1).
next(prolog.query(filename.join(["load_files('", "',[])"])))
print(list(prolog.query("foo(X,1)"))) # ==> [{X:1}]
query = "unload_file('{}')".format(filename)
print(query)
next(prolog.query(query))
print(list(prolog.query("foo(X,1)"))) # ==> [{X:1}] -- should have failed with missing 'f'
The behavior I get from Prolog is:
?- load_files(f,[]).
true.
?- foo(X,1).
X = 1.
?- unload_file(f). .
true.
?- foo(X,1).
ERROR: Undefined procedure: foo/2 (DWIM could not correct goal)
Is the different behavior here a bug? (I'd like to load and unload files to keep unit tests independent in Python).