sthiele/pyasp

A convenience wrapper for the ASP tools gringo, gringo4 and clasp

pyasp's Issues

Why do you require both gringo3 and gringo4?

On FreeBSD, I only have gringo-4. Sholdn't the latest version be enough?

Constants in parameters of solver.run() method can't have space in their names

Here is the p.py file:

from pyasp import asp
solver = asp.Gringo4Clasp(gringo_options='-c v="text with spaces in it"')
solver.run([], additionalProgramText='#const v=1. p(v).')  # error here

Here is the stack trace (python 3):

Traceback (most recent call last):
  File "p.py", line 6, in <module>
    solver.run([], additionalProgramText='#const v=1. p(v).')
  File "/udd/lbourneu/.local/lib/python3.4/site-packages/pyasp/asp.py", line 383, in run
    grounding = self.__ground__(programs, additionalProgramText)
  File "/udd/lbourneu/.local/lib/python3.4/site-packages/pyasp/asp.py", line 345, in __ground__
    (self._gringo.returncode, self.gringo_stderr))
Exception: got error 1 from gringo: 'b'<v="text>:1:4: error: lexer error, unexpected "\n\n<cmd>: error: file could not be opened:\n  with\n\n<cmd>: error: file could not be opened:\n  spaces\n\n<cmd>: error: file could not be opened:\n  in\n\n<cmd>: error: file could not be opened:\n  it"\n\n*** ERROR: (gringo): grounding stopped because of errors\n''

Using gringo CLI, an error appears if supplementary quotes are not provided:

gringo4 l.lp -c v='"text with spaces in it"'

(with "l.lp" file containing "#const v=1. p(v).")

Doesn't print error messagew when files are missing

I tried an example from:
https://sthiele.github.io/posts/2015/october/pyasp_intro.html
When .lp files are missing, this statement

solver.run([encoding, facts], collapseTerms=True, collapseAtoms=False)

doesn't print error messages.

`--time-limit` option not supported

Using the --time-limit=1 option of clasp, the following error should appear when the solver is stopped by the signal.
I think its because pyasp is not designed to handle any outputed data when an interruption occurs.

File "/udd/lbourneu/.local/lib/python3.4/site-packages/pyasp/asp.py", line 146, in run
    solving = self.__solve__(grounding)
  File "/udd/lbourneu/.local/lib/python3.4/site-packages/pyasp/asp.py", line 136, in __solve__
    raise EnvironmentError(error)
OSError: got error 1 from clasp:
{
  "Solver": "clasp version 3.1.3",
  "Input": [
    "stdin"
  ],
  "Call": [
    {

    }
  ],
  "Result": "UNKNOWN",
  "TIME LIMIT": 1,
  "Models": {
    "Number": 0,
    "More": "yes"
  },
  "Calls": 1,
  "Time": {
    "Total": 1.000,
    "Solve": 0.788,
    "Model": 0.000,
    "Unsat": 0.000,
    "CPU": 0.990
  }
}
*** Info : (clasp): INTERRUPTED by signal!

This should be supported in a next pyasp version.
I will work on a minimal reproductible code example to getting this error.

Fixing it will require some work on the parser, in order to extract all models found before interruption.

Access versions number and text of binaries programmatically

For logging and testing purpose, the versions and version text of binaries of clasp and gringo can be useful. These information could be accessed programatically.

API exemple for gringo:

from pyasp import asp
print('GRINGO VERSION:', asp.Gringo4.version(), '\n')
print(asp.Gringo4.version(full_text=True))

output:

GRINGO VERSION: 4.5.3

gringo version 4.5.3
Address model: 64-bit
Configuration: without Python, with Lua 5.2.3
Copyright (C) Roland Kaminski
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
Gringo is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

API exemple for clasp:

from pyasp import asp
print('CLASP VERSION:', asp.Clasp.version(), '\n')
print(asp.Clasp.version(full_text=True))

output:

CLASP VERSION: 3.1.4

clasp version 3.1.4
Address model: 32-bit
Configuration: WITH_THREADS=1 (Intel TBB version 4.0)
Copyright (C) Benjamin Kaufmann
License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>
clasp is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Currently, just call the solver with the --version option is not working, because of the parser that try to parse the version text.
A routine that call the binaries without call the parser could return the stdout output. (or use a regex to extract the version number)

Threading option of Clasp leads to 'OPTIMUM FOUND but zero optimals' warning and no model

It appears that define the --parallel-mode clasp option leads to a warning, and an unsatisfiable result. (no model found)

Here is the python program:

from pyasp import asp


PROGRAM = """

% choose two values
values(1..10).
2 {choosen(X): values(X)} 2.

% score is the sum of the values
score(S):- S=#sum{X:choosen(X)}.

% maximize the score
#maximize{S:score(S)}.

#show.
#show choosen/1.
#show score/1.

"""


def test(clasp_options):
    solver = asp.Gringo4Clasp(clasp_options=clasp_options)
    return solver.run([], additionalProgramText=PROGRAM)


print('FIRST: no clasp option:')
print('answers:', test(''))
print('-----------------------')
print('SECOND: use 2 threads:')
print('answers:', test('--parallel-mode=2'))

Result (python 3.4.3):

FIRST: no clasp option:
answers: [TermSet({'score(19)', 'choosen(10)', 'choosen(9)'})]
-----------------------
SECOND: use 2 threads:
WARNING: OPTIMUM FOUND but zero optimals
answers: []

Unit testing don't cover *misc.py*

The file misc.py is not covered by unit testing, which raise no error after deleting all lines in that file.

The asp.py module import all objects of misc.py module, but don't use any of them.
Is misc.py only kept for further development ?

[security problem] You need to check hash of downloaded files

You can't download binaries without checking cryptographic hash: https://github.com/sthiele/pyasp/blob/master/setup.py#L128 Users will get MITMed. https://en.wikipedia.org/wiki/Man-in-the-middle_attack

Either delete these downloads, or store and check cryptographic hashes. I recommend: you should rely on the installed packages for gringo and clasp, and not try to install anything yourself.