add has (var_name) to ParsedExpression

CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.0)
 
 set(wccl_ver_major "0")
 set(wccl_ver_minor "1")
-set(wccl_ver_patch "3")
+set(wccl_ver_patch "4")
 
 set(LIBWCCL_VERSION "${wccl_ver_major}.${wccl_ver_minor}.${wccl_ver_patch}")
 

libwccl/ops/parsedexpression.h

@@ -129,6 +129,14 @@ public:
 	template<class T>
 	void set(const std::string& var_name, const T& value);
 
+	/**
+	 * Checks if has a variable with given name and type.
+	 * @returns if such variable exists AND is of type T.
+	 * @param var_name Variable name.
+	 */
+	template<class T>
+	bool has(const std::string& var_name);
+
 	/**
 	 * Sets all variables to their default values.
 	 * @note Values of variables are preserved between applications
@@ -235,6 +243,12 @@ void ParsedExpression::set(const std::string& var_name, const T& value) {
 	get<T>(var_name) = value;
 }
 
+template<class T>
+bool ParsedExpression::has(const std::string& var_name) {
+	boost::shared_ptr<T> value = variables_->get<T>(var_name);
+	return value;
+}
+
 inline
 void ParsedExpression::clean()
 {

swig/parsedexpression.i

@@ -43,7 +43,15 @@ namespace Wccl {
     %template(get_position) get<Position>;
     %template(get_match) get<Match>;
 
-    /* --------------------------------------------------------------------- */    
+    template<class T> bool has(const std::string& var_name);
+    %template(has_bool) has<Bool>;
+    %template(has_tset) has<TSet>;
+    %template(has_strset) has<StrSet>;
+    %template(has_position) has<Position>;
+    %template(has_match) has<Match>;
+    
+    /* Those functions are overridden later to handle shared_ptr values,
+     * anyway they are needed for those overrides to work. */
     template<class T> void set(const std::string& var_name, const T& value);
     %template(set_bool) set<Bool>;
     %template(set_tset) set<TSet>;