VarGetter, operator getting value of a variable.

It is used wherever in WCCL variable is seen in read-only context, i.e. outside of operators that are setting its value like setvar.

libwccl/ops/vargetter.h

+#ifndef LIBWCCL_OPS_VARGETTER_H
+#define LIBWCCL_OPS_VARGETTER_H
+
+#include <libwccl/ops/functions.h>
+
+namespace Wccl {
+
+
+/**
+ * Operator that returns value of a variable of given type T
+ */
+template<class T>
+class VarGetter : public Function<T> {
+public:
+	VarGetter(const VariableAccesor<T>& var_acc)
+		: var_acc_(var_acc)
+	{
+	}
+	
+	/**
+	 * @returns Operator name for variable getter, we assume "$", although real
+	 * string representation depends on given Value's var_repr function
+	 */
+	virtual const std::string raw_operator_name() const {
+		return "$";
+	}
+
+	/**
+	 * @returns String representation of the variable getter which is
+	 * equal to string representation of the underlying variable.
+	 */
+	virtual std::string to_raw_string() const {
+		return T::var_repr(var_acc_.get_name());
+	}
+
+	/**
+	 * @returns String representation of the variable getter which is
+	 * equal to string representation of the underlying variable.
+	 */
+	virtual std::string to_string(const Corpus2::Tagset&) const {
+		return T::var_repr(var_acc_.get_name());
+	}
+protected:
+	/**
+	 * Return value held by the underlying variable.
+	 */
+	virtual BaseRetValPtr apply_internal(const FunExecContext& context) const {
+		return context.variables()->get_fast(var_acc_);
+	}
+
+private:
+	const VariableAccesor<T> var_acc_;
+};
+
+
+} /* end ns Wccl */
+
+#endif // LIBWCCL_OPS_VARGETTER_H

tests/CMakeLists.txt

@@ -15,6 +15,7 @@ add_executable(tests
 	strsetfunctions.cpp
 	values.cpp
 	varaccess.cpp
+	vargetter.cpp
 	variables.cpp
 )
 

tests/vargetter.cpp

+#include <boost/test/unit_test.hpp>
+#include <boost/bind.hpp>
+
+#include <libwccl/ops/vargetter.h>
+#include <libwccl/values/bool.h>
+#include <libwccl/values/tset.h>
+#include <libwccl/values/strset.h>
+#include <libwccl/ops/constant.h>
+
+using namespace Wccl;
+
+BOOST_AUTO_TEST_SUITE(vargetter)
+
+struct VarGetFix
+{
+	VarGetFix()
+		: sc(boost::make_shared<Corpus2::Sentence>()),
+		  cx(sc, boost::make_shared<Variables>()),
+		  tagset(),
+		  true_value(true),
+		  false_value(false),
+		  true_constant(true_value),
+		  false_constant(false_value)
+	{
+		cx.variables()->put("True_bool", true_value);
+		cx.variables()->put("False_bool", false_value);
+	}
+	SentenceContext sc;
+	FunExecContext cx;
+	Corpus2::Tagset tagset;
+
+	Bool true_value;
+	Bool false_value;
+	Constant<Bool> true_constant;
+	Constant<Bool> false_constant;
+};
+
+BOOST_FIXTURE_TEST_CASE(bool_apply, VarGetFix)
+{
+	VariableAccesor<Bool> acc_t = cx.variables()->create_accesor<Bool>("True_bool");
+	VarGetter<Bool> var_getter_t(acc_t);
+	BOOST_CHECK_EQUAL(true, var_getter_t.apply(cx)->get_value());
+	VariableAccesor<Bool> acc_f = cx.variables()->create_accesor<Bool>("False_bool");
+	VarGetter<Bool> var_getter_f(acc_f);
+	BOOST_CHECK_EQUAL(false, var_getter_f.apply(cx)->get_value());
+}
+
+BOOST_FIXTURE_TEST_CASE(bool_apply_acc_destruct, VarGetFix)
+{
+	boost::shared_ptr<VarGetter<Bool> > var_getter;
+	{
+		VariableAccesor<Bool> acc_t = cx.variables()->create_accesor<Bool>("True_bool");
+		var_getter.reset(new VarGetter<Bool>(acc_t));
+	}
+	BOOST_CHECK_EQUAL(true, var_getter->apply(cx)->get_value());
+}
+
+BOOST_FIXTURE_TEST_CASE(bool_mod, VarGetFix)
+{
+	VariableAccesor<Bool> acc_t = cx.variables()->create_accesor<Bool>("True_bool");
+	VarGetter<Bool> var_getter_t(acc_t);
+	BOOST_CHECK_EQUAL(true, var_getter_t.apply(cx)->get_value());
+	cx.variables()->get<Bool>("True_bool")->set_value(false);
+	BOOST_CHECK_EQUAL(false, var_getter_t.apply(cx)->get_value());
+	cx.variables()->put("True_bool", Bool(true));
+	BOOST_CHECK_EQUAL(true, var_getter_t.apply(cx)->get_value());
+	cx.variables()->set("True_bool", false_value);
+	BOOST_CHECK_EQUAL(false, var_getter_t.apply(cx)->get_value());
+	cx.variables()->set("True_bool", Bool(true));
+	BOOST_CHECK_EQUAL(true, var_getter_t.apply(cx)->get_value());
+}
+
+//----  To String -----
+
+BOOST_FIXTURE_TEST_CASE(bool_varget_to_string, VarGetFix)
+{
+	VariableAccesor<Bool> acc_t = cx.variables()->create_accesor<Bool>("True_bool");
+	VarGetter<Bool> var_getter_t(acc_t);
+	BOOST_CHECK_EQUAL(Bool::var_repr("True_bool"), var_getter_t.to_string(tagset));
+}
+
+BOOST_FIXTURE_TEST_CASE(bool_varget_to_raw_string, VarGetFix)
+{
+	VariableAccesor<Bool> acc_t = cx.variables()->create_accesor<Bool>("True_bool");
+	VarGetter<Bool> var_getter_t(acc_t);
+	BOOST_CHECK_EQUAL(Bool::var_repr("True_bool"), var_getter_t.to_raw_string());
+}
+
+BOOST_AUTO_TEST_SUITE_END()