Improve implementation of #63 and add some further tests

src/tarski/fstrips/representation.py

@@ -141,9 +141,12 @@ def collect_effect_free_parameters(action: Action):
     return parameters.difference(free)
 
 
-def project_away_effect_free_variables(action: Action):
+def project_away_effect_free_variables(action: Action, inplace=False):
     """ Return an action schema which is equivalent to the given `action` except that all "effect-free" parameters have
-    been compiled away into existential variables in the precondition. Hence, an action
+    been compiled away into existential variables in the precondition. The value of `inplace` determines whether
+    the modification will be done in-place to the given action, or a new action will be created.
+
+    As an example, an action
 
     action a(x, y, z)
         PRE: p(x, y) and q(y, z)
@@ -158,12 +161,23 @@ def project_away_effect_free_variables(action: Action):
     """
     free = collect_effect_free_parameters(action)
     bound = [x for x in action.parameters if symref(x) not in free]
-    projected = copy.deepcopy(action)
+    projected = action if inplace else copy.deepcopy(action)
     projected.parameters = VariableBinding(bound)
     projected.precondition = exists(*(x.expr for x in free), action.precondition)
     return projected
 
 
+def project_away_effect_free_variables_from_problem(problem: Problem, inplace=False):
+    """ Return a new problem equivalent to the given one but where all action schemas have had their "effect-free"
+     parameters compiled away into existential variables in the precondition. The value of `inplace` determines whether
+    the modification will be done in-place to the given problem, or a new problem will be created.
+    """
+    # If not modifying inplace, we copy the full problem (including its actions) and then modify that one inplace
+    projected = problem if inplace else copy.deepcopy(problem)
+    _ = [project_away_effect_free_variables(action, inplace=True) for action in projected.actions.values()]
+    return projected
+
+
 def collect_effect_free_variables(eff: fs.BaseEffect):
     """ Return the set of all variables that appear free in the given effect. """
     free = set()

tests/fstrips/test_representation.py

@@ -1,6 +1,6 @@
 
 from tarski.fstrips.representation import collect_effect_free_parameters, project_away_effect_free_variables, \
-    collect_effect_free_variables
+    collect_effect_free_variables, project_away_effect_free_variables_from_problem
 from tarski.syntax import exists, land
 from tarski.fstrips import representation as rep
 
@@ -100,9 +100,17 @@ def test_effect_free_variables_in_caldera():
     assert names == ['?v01']
 
     projected = project_away_effect_free_variables(act)
-    names = sorted(x.symbol for x in projected.parameters)
-    assert names == ['?v01']
-
-
-
-
+    names1 = sorted(x.symbol for x in act.parameters)
+    names2 = sorted(x.symbol for x in projected.parameters)
+    assert names1 == ['?v00', '?v01', '?v02'] and names2 == ['?v01']
+
+    # Check inplace argument works as expected
+    problem2 = project_away_effect_free_variables_from_problem(problem, inplace=False)
+    names1 = sorted(x.symbol for x in problem.get_action('get_domain').parameters)
+    names2 = sorted(x.symbol for x in problem2.get_action('get_domain').parameters)
+    assert names1 == ['?v00', '?v01', '?v02'] and names2 == ['?v01']
+
+    problem2 = project_away_effect_free_variables_from_problem(problem, inplace=True)
+    names1 = sorted(x.symbol for x in problem.get_action('get_domain').parameters)
+    names2 = sorted(x.symbol for x in problem2.get_action('get_domain').parameters)
+    assert names1 == names2 == ['?v01']