StateGenerator

src/storage/expressions.cpp

@@ -39,6 +39,8 @@ void define_expressions(py::module& m) {
         .def("has_numerical_type", &storm::expressions::Variable::hasNumericalType, "Check if the variable is of numerical type")
         .def("has_bitvector_type", &storm::expressions::Variable::hasBitVectorType, "Check if the variable is of bitvector type")
         .def("get_expression", &storm::expressions::Variable::getExpression, "Get expression from variable")
+        .def("__eq__", &storm::expressions::Variable::operator==)
+        .def("__hash__", &storm::expressions::Variable::getIndex)
     ;
 
 

src/storage/prism.cpp

@@ -1,12 +1,25 @@
 #include "prism.h"
 #include <storm/storage/prism/Program.h>
+#include <boost/variant.hpp>
 #include "src/helpers.h"
 #include <storm/storage/expressions/ExpressionManager.h>
 #include <storm/storage/jani/Model.h>
 #include <storm/storage/jani/Property.h>
+#include <storm/generator/NextStateGenerator.h>
+#include <storm/generator/Choice.h>
+#include <storm/generator/PrismNextStateGenerator.h>
+#include "storm/exceptions/NotSupportedException.h"
+#include <storm/storage/expressions/SimpleValuation.h>
+#include "storm/exceptions/InvalidTypeException.h"
+#include "storm/exceptions/InvalidStateException.h"
+#include "storm/exceptions/InvalidAccessException.h"
+
 
 using namespace storm::prism;
 
+template <typename StateType, typename ValueType>
+void define_stateGeneration(py::module& m);
+
 void define_prism(py::module& m) {
     py::class_<storm::prism::Program, std::shared_ptr<storm::prism::Program>> program(m, "PrismProgram", "A Prism Program");
     program.def_property_readonly("constants", &Program::getConstants, "Get Program Constants")
@@ -38,21 +51,27 @@ void define_prism(py::module& m) {
             .def_property_readonly("name", &Module::getName, "Name of the module")
             .def_property_readonly("integer_variables", &Module::getIntegerVariables, "All integer Variables of this module")
             .def_property_readonly("boolean_variables", &Module::getBooleanVariables, "All boolean Variables of this module")
+            .def("__str__", &streamToString<Module>)
             ;
 
     py::class_<Command> command(m, "PrismCommand", "A command in a Prism program");
     command.def_property_readonly("global_index", &Command::getGlobalIndex, "Get global index")
             .def_property_readonly("guard_expression", &Command::getGuardExpression, "Get guard expression")
-            .def_property_readonly("updates", &Command::getUpdates, "Updates in the command");
+            .def_property_readonly("updates", &Command::getUpdates, "Updates in the command")
+            .def("__str__", &streamToString<Command>)
+            ;
 
     py::class_<Update> update(m, "PrismUpdate", "An update in a Prism command");
     update.def_property_readonly("assignments", &Update::getAssignments, "Assignments in the update")
            .def_property_readonly("probability_expression", &Update::getLikelihoodExpression, "The probability expression for this update")
-           ;//Added by Kevin
+           .def("__str__", &streamToString<Update>)
+           ;
 
     py::class_<Assignment> assignment(m, "PrismAssignment", "An assignment in prism");
     assignment.def_property_readonly("variable", &Assignment::getVariable, "Variable that is updated")
-            .def_property_readonly("expression", &Assignment::getExpression, "Expression for the update");
+            .def_property_readonly("expression", &Assignment::getExpression, "Expression for the update")
+            .def("__str__", &streamToString<Assignment>)
+            ;
 
 
 
@@ -85,9 +104,183 @@ void define_prism(py::module& m) {
     py::class_<IntegerVariable, std::shared_ptr<IntegerVariable>> integer_variable(m, "Prism_Integer_Variable", variable, "A program integer variable in a Prism program");
     integer_variable.def_property_readonly("lower_bound_expression", &IntegerVariable::getLowerBoundExpression, "The the lower bound expression of this integer variable")
                     .def_property_readonly("upper_bound_expression", &IntegerVariable::getUpperBoundExpression, "The the upper bound expression of this integer variable")
+                    .def("__str__", &streamToString<IntegerVariable>)
                     ;
 
     py::class_<BooleanVariable, std::shared_ptr<BooleanVariable>> boolean_variable(m, "Prism_Boolean_Variable", variable, "A program boolean variable in a Prism program");
+    boolean_variable.def("__str__", &streamToString<BooleanVariable>);
+
+    define_stateGeneration<uint32_t, storm::RationalNumber>(m);
+}
+
+class ValuationMapping {
+    public:
+    std::map<storm::expressions::Variable, bool> booleanValues;
+    std::map<storm::expressions::Variable, int_fast64_t> integerValues;
+    std::map<storm::expressions::Variable, double> rationalValues;
+
+    ValuationMapping(storm::prism::Program const& program,
+                     storm::expressions::SimpleValuation valuation) {
+        auto const& variables = program.getManager().getVariables();
+        for (auto const& variable : variables) {
+            if (variable.hasBooleanType()) {
+                booleanValues[variable] = valuation.getBooleanValue(variable);
+            } else if (variable.hasIntegerType()) {
+                integerValues[variable] = valuation.getIntegerValue(variable);
+            } else if (variable.hasRationalType()) {
+                rationalValues[variable] = valuation.getRationalValue(variable);
+            } else {
+                STORM_LOG_THROW(false, storm::exceptions::InvalidTypeException,
+                        "Unexpected variable type.");
+            }
+        }
+    }
+
+    std::string toString() const {
+        std::vector<std::string> strs;
+        for (auto const& value : booleanValues) {
+            std::stringstream sstr;
+            sstr << value.first.getName() + "=";
+            sstr << value.second;
+            strs.push_back(sstr.str());
+        }
+        for (auto const& value : integerValues) {
+            std::stringstream sstr;
+            sstr << value.first.getName() + "=";
+            sstr << value.second;
+            strs.push_back(sstr.str());
+        }
+        for (auto const& value : rationalValues) {
+            std::stringstream sstr;
+            sstr << value.first.getName() + "=";
+            sstr << value.second;
+            strs.push_back(sstr.str());
+        }
+        return "[" + boost::join(strs, ",") + "]";
+    }
+};
+
+template <typename StateType, typename ValueType>
+class StateGenerator {
+    typedef std::unordered_map<StateType, storm::generator::CompressedState> IdToStateMap;
+    typedef std::vector<std::pair<StateType, ValueType>> distribution_type;
+    typedef distribution_type choice_type; // currently we just collapse choices into distributions
+    typedef std::vector<choice_type> choice_list_type;
+
+    storm::prism::Program const& program;
+    storm::generator::PrismNextStateGenerator<ValueType, StateType> generator;
+    std::function<StateType (storm::generator::CompressedState const&)> stateToIdCallback;
+    // this needs to be below the generator attribute,
+    // because its initialization depends on the generator being initialized.
+    // #justcppthings
+    storm::storage::sparse::StateStorage<StateType> stateStorage;
+    bool hasComputedInitialStates = false;
+    IdToStateMap stateMap;
+    boost::optional<StateType> currentStateIndex;
+
+    public:
+        StateGenerator(storm::prism::Program const& program_) : program(program_), generator(program_), stateStorage(generator.getStateSize()) {
+            stateToIdCallback = [this] (storm::generator::CompressedState const& state) -> StateType {
+                StateType newIndex = stateStorage.getNumberOfStates();
+                std::pair<StateType, std::size_t> indexBucketPair = stateStorage.stateToId.findOrAddAndGetBucket(state, newIndex);
+                StateType index = indexBucketPair.first;
+                stateMap[index] = state;
+                return index;
+            };
+        }
+
+        StateType loadInitialState() {
+            if (!hasComputedInitialStates) {
+                stateStorage.initialStateIndices = generator.getInitialStates(stateToIdCallback);
+                hasComputedInitialStates = true;
+            }
+            STORM_LOG_THROW(stateStorage.initialStateIndices.size() == 1, storm::exceptions::NotSupportedException, "Currently only models with one initial state are supported.");
+            StateType initialStateIndex = stateStorage.initialStateIndices.front();
+            load(initialStateIndex);
+            return initialStateIndex;
+        }
+
+        void load(StateType stateIndex) {
+            if (currentStateIndex && *currentStateIndex == stateIndex) {
+                return;
+            }
+            auto search = stateMap.find(stateIndex);
+            if (search == stateMap.end()) {
+                STORM_LOG_THROW(false, storm::exceptions::InvalidAccessException,
+                        "state id not found");
+            }
+            generator.load(search->second);
+            currentStateIndex = stateIndex;
+        }
+
+        ValuationMapping currentStateToValuation() {
+            if (!currentStateIndex) {
+                STORM_LOG_THROW(false, storm::exceptions::InvalidStateException,
+                        "Initial state not initialized");
+            }
+            auto valuation = generator.toValuation(stateMap[*currentStateIndex]);
+            return ValuationMapping(program, valuation);
+        }
+
+        bool satisfies(storm::expressions::Expression const& expression) {
+            return generator.satisfies(expression);
+        }
+
+        choice_list_type expand() {
+            if (!hasComputedInitialStates) {
+                STORM_LOG_THROW(false, storm::exceptions::InvalidStateException,
+                        "Initial state not initialized");
+            }
+            choice_list_type choices_result;
+            auto behavior = generator.expand(stateToIdCallback);
+            for (auto choice : behavior.getChoices()) {
+                choices_result.push_back(choice_type(choice.begin(), choice.end()));
+            }
+
+            return choices_result;
+        }
+
+};
+
+template <typename StateType, typename ValueType>
+void define_stateGeneration(py::module& m) {
+    py::class_<ValuationMapping, std::shared_ptr<ValuationMapping>> valuation_mapping(m, "ValuationMapping", "A valuation mapping for a state consists of a mapping from variable to value for each of the three types.");
+    valuation_mapping
+        .def_readonly("boolean_values", &ValuationMapping::booleanValues)
+        .def_readonly("integer_values", &ValuationMapping::integerValues)
+        .def_readonly("rational_values", &ValuationMapping::rationalValues)
+        .def("__str__", &ValuationMapping::toString);
+
+    py::class_<StateGenerator<StateType, ValueType>, std::shared_ptr<StateGenerator<StateType, ValueType>>> state_generator(m, "StateGenerator", R"doc(
+        Interactively explore states using Storm's PrismNextStateGenerator.
+
+        :ivar program: A PRISM program.
+    )doc");
+    state_generator
+        .def(py::init<storm::prism::Program const&>())
+        .def("load_initial_state", &StateGenerator<StateType, ValueType>::loadInitialState, R"doc(
+            Loads the (unique) initial state.
+            Multiple initial states are not supported.
+
+            :rtype: the ID of the initial state.
+        )doc")
+        .def("load", &StateGenerator<StateType, ValueType>::load, R"doc(
+            :param state_id: The ID of the state to load.
+        )doc")
+        .def("current_state_to_valuation", &StateGenerator<StateType, ValueType>::currentStateToValuation, R"doc(
+            Return a valuation for the currently loaded state.
+
+            :rtype: stormpy.ValuationMapping
+        )doc")
+        .def("current_state_satisfies", &StateGenerator<StateType, ValueType>::satisfies, R"doc(
+            Check if the currently loaded state satisfies the given expression.
 
+            :param stormpy.Expression expression: The expression to check against.
+            :rtype: bool
+        )doc")
+        .def("expand", &StateGenerator<StateType, ValueType>::expand, R"doc(
+            Expand the currently loaded state and return its successors.
 
+            :rtype: [[(state_id, probability)]]
+        )doc");
 }

src/storage/valuation.cpp

@@ -18,4 +18,5 @@ void define_simplevaluation(py::module& m) {
     py::class_<storm::expressions::SimpleValuation, std::shared_ptr<storm::expressions::SimpleValuation>> simplevaluation(m, "SimpleValuation",  "Valuations for storm variables");
     simplevaluation.def("get_boolean_value", &storm::expressions::SimpleValuation::getBooleanValue);
     simplevaluation.def("get_integer_value", &storm::expressions::SimpleValuation::getIntegerValue);
+    simplevaluation.def("__str__", &storm::expressions::SimpleValuation::toString);
 }

tests/storage/test_state_generation.py

@@ -0,0 +1,75 @@
+import stormpy
+from stormpy.examples.files import prism_dtmc_die
+
+class _DfsQueue:
+    def __init__(self):
+        self.queue = []
+        self.visited = set()
+
+    def push(self, state_id):
+        if state_id not in self.visited:
+            self.queue.append(state_id)
+            self.visited.add(state_id)
+
+    def pop(self):
+        if len(self.queue) > 0:
+            return self.queue.pop()
+        return None
+
+
+def _dfs_explore(program, callback):
+    generator = stormpy.StateGenerator(program)
+
+    queue = _DfsQueue()
+    current_state_id = generator.load_initial_state()
+    queue.visited.add(current_state_id)
+
+    while True:
+        callback(current_state_id, generator)
+
+        successors = generator.expand()
+        assert len(successors) <= 1
+        for choice in successors:
+            for state_id, _prob in choice:
+                queue.push(state_id)
+        current_state_id = queue.pop()
+        if current_state_id is None:
+            break
+        generator.load(current_state_id)
+
+
+def _load_program(filename):
+    program = stormpy.parse_prism_program(filename)  # pylint: disable=no-member
+    program = program.substitute_constants()
+
+    expression_parser = stormpy.ExpressionParser(program.expression_manager)
+    expression_parser.set_identifier_mapping(
+        {var.name: var.get_expression()
+         for var in program.variables})
+    return program, expression_parser
+
+
+def _find_variable(program, name):
+    for var in program.variables:
+        if var.name is name:
+            return var
+    return None
+
+def test_knuth_yao_die():
+    program, expression_parser = _load_program(prism_dtmc_die)
+    s_variable = _find_variable(program, "s")
+    upper_bound_invariant = expression_parser.parse("d <= 6")
+
+    number_states = 0
+
+    def callback(_state_id, generator):
+        nonlocal number_states
+        number_states += 1
+
+        valuation = generator.current_state_to_valuation()
+        print(valuation)
+        assert valuation.integer_values[s_variable] <= 7
+        assert generator.current_state_satisfies(upper_bound_invariant)
+
+    _dfs_explore(program, callback)
+    assert number_states == 13