ListTerm.cpp

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/*
 * This file is part of KnowRob, please consult
 * https://github.com/knowrob/knowrob for license details.
 */
 
#include <gtest/gtest.h>
#include "knowrob/terms/ListTerm.h"
#include "knowrob/terms/String.h"
#include "knowrob/integration/python/utils.h"
 
using namespace knowrob;
 
ListTerm::ListTerm(const std::vector<TermPtr> &elements)
        : Function(listFunctor(), elements) {
}
 
const AtomPtr &ListTerm::listFunctor() {
    static const AtomPtr fun = Atom::Tabled("[]");
    return fun;
}
 
std::shared_ptr<ListTerm> ListTerm::nil() {
    static std::shared_ptr<ListTerm> x(new ListTerm(
            std::vector<std::shared_ptr<Term>>(0)));
    return x;
}
 
bool ListTerm::isNIL() const {
    return arguments_.empty();
}
 
void ListTerm::write(std::ostream &os) const {
    os << '[';
    for (uint32_t i = 0; i < arguments_.size(); i++) {
        os << *arguments_[i];
        if (i + 1 < arguments_.size()) {
            os << ',' << ' ';
        }
    }
    os << ']';
}
 
namespace knowrob::py {
    template<>
    void createType<ListTerm>() {
        using namespace boost::python;
        class_<ListTerm, std::shared_ptr<ListTerm>, bases<Function>>
                ("ListTerm", init<const std::vector<TermPtr> &>())
                .def("__iter__", range(&ListTerm::begin, &ListTerm::end))
                .def("isNIL", &ListTerm::isNIL)
                .def("elements", &ListTerm::elements, return_value_policy<copy_const_reference>());
    }
}
 
/******************************************/
/************** Unit Tests ****************/
/******************************************/
 
TEST(list_term, NIL) {
    EXPECT_TRUE(ListTerm::nil()->elements().empty());
    EXPECT_TRUE(ListTerm({}).elements().empty());
    EXPECT_TRUE(ListTerm({}).isNIL());
    EXPECT_FALSE(ListTerm::nil()->isAtomic());
    EXPECT_TRUE(ListTerm::nil()->isGround());
}
 
TEST(list_term, lists) {
    auto x = std::make_shared<String>("x");
    auto y = std::make_shared<String>("y");
    EXPECT_TRUE(ListTerm({x}).isGround());
    EXPECT_FALSE(ListTerm({x}).isAtomic());
    EXPECT_FALSE(ListTerm({x}).elements().empty());
    EXPECT_EQ(ListTerm({x, y}).elements()[0], x);
    EXPECT_EQ(ListTerm({x, y}).elements()[1], y);
}