Add documented example usage for C++ api. To be used for website documentation purposes as well

include/chaiscript/chaiscript.hpp

@@ -85,17 +85,22 @@ namespace chaiscript
     /**
      * Errors generated inside the parser
      */
-    struct Parse_Error {
+    struct Parse_Error : public std::runtime_error {
         std::string reason;
         File_Position position;
         const char *filename;
 
         Parse_Error(const std::string &why, const File_Position &where, const char *fname) :
-            reason(why), position(where), filename(fname) { }
+            std::runtime_error("Parse error: \"" + why + "\" in '"
+                + std::string(fname) + "' at: (" + boost::lexical_cast<std::string>(where.line+1) + ", " +
+                 boost::lexical_cast<std::string>(where.column) + ")"),
+            reason(why), position(where), filename(fname) 
+        { }
 
-        Parse_Error(const std::string &why, const TokenPtr &where) : reason(why) {
-            filename = where->filename;
-            position = where->start;
+        Parse_Error(const std::string &why, const TokenPtr &where) 
+            : std::runtime_error("Parse error: \"" + why + "\" in '"
+                + where->filename + "' line: " + boost::lexical_cast<std::string>(where->start.line+1)),
+              reason(why), position(where->start), filename(where->filename) {
         }
 
         virtual ~Parse_Error() throw() {}

include/chaiscript/dispatchkit/function_call.hpp

@@ -62,7 +62,7 @@ namespace dispatchkit
 }
 
 #define BOOST_PP_ITERATION_LIMITS ( 0, 9 )
-#define BOOST_PP_FILENAME_1 "function_call.hpp"
+#define BOOST_PP_FILENAME_1 <chaiscript/dispatchkit/function_call.hpp>
 #include BOOST_PP_ITERATE()
 
 namespace dispatchkit

src/example.cpp

@@ -0,0 +1,86 @@
+#include <iostream>
+
+#include <chaiscript/chaiscript.hpp>
+#include <chaiscript/dispatchkit/function_call.hpp>
+#include <boost/function.hpp>
+#include <boost/date_time/posix_time/posix_time.hpp>
+#include <boost/regex.hpp>
+
+void log(const std::string &msg)
+{
+  std::cout << "[" << boost::posix_time::microsec_clock::local_time() << "] " << msg << std::endl;
+}
+
+void log(const std::string &module, const std::string &msg)
+{
+  std::cout << "[" << boost::posix_time::microsec_clock::local_time() << "] <" << module << "> " << msg << std::endl;
+}
+
+struct System
+{
+  std::map<std::string, boost::function<std::string (const std::string &) > > m_callbacks;
+
+  void add_callback(const std::string &t_name, 
+      boost::shared_ptr<dispatchkit::Proxy_Function> t_func)
+  {
+    m_callbacks[t_name] = dispatchkit::build_function_caller<std::string (const std::string &)>(t_func);
+  }
+
+
+  void do_callbacks(const std::string &inp)
+  {
+    log("Running Callbacks: " + inp);
+    for (std::map<std::string, boost::function<std::string (const std::string &)> >::iterator itr = m_callbacks.begin();
+         itr != m_callbacks.end();
+         ++itr)
+    {
+      log("Callback: " + itr->first, itr->second(inp));
+    }
+  }
+};
+
+
+int main(int argc, char *argv[]) {
+
+
+  chaiscript::ChaiScript_Engine chai;
+
+  //Create a new system object and share it with the chaiscript engine
+  System system;
+  chai.get_eval_engine().add_object("system", boost::ref(system));
+
+  //Register the two methods of the System structure.
+  dispatchkit::register_function(chai.get_eval_engine(), &System::add_callback, "add_callback");
+  dispatchkit::register_function(chai.get_eval_engine(), &System::do_callbacks, "do_callbacks");
+
+  // Let's use chaiscript to add a new lambda callback to our system. 
+  // The function "{ 'Callback1' + x }" is created in chaiscript and passed into our C++ application
+  // in the "add_callback" function of struct System the chaiscript function is converted into a 
+  // boost::function, so it can be handled and called easily and type-safely
+  chai.evaluate_string("system.add_callback('#1', fun(x) { 'Callback1 ' + x });");
+  
+  // Because we are sharing the "system" object with the chaiscript engine we have equal
+  // access to it both from within chaiscript and from C++ code
+  system.do_callbacks("TestString");
+  chai.evaluate_string("system.do_callbacks(\"TestString\");");
+
+  // The log function is overloaded, therefore we have to give the C++ compiler a hint as to which
+  // version we want to register. One way to do this is to create a typedef of the function pointer
+  // then cast your function to that typedef.
+  typedef void (*PlainLog)(const std::string &);
+  typedef void (*ModuleLog)(const std::string &, const std::string &);
+  dispatchkit::register_function(chai.get_eval_engine(), PlainLog(&log), "log");
+  dispatchkit::register_function(chai.get_eval_engine(), ModuleLog(&log), "log");
+
+  chai.evaluate_string("log('Test Message')");
+  chai.evaluate_string("log('Test Module', 'Test Message');");
+
+  //Finally, it is possible to register any boost::function as a system function, in this 
+  //way, we can, for instance add a bound member function to the system
+  chai.get_eval_engine().register_function(boost::function<void ()>(boost::bind(&System::do_callbacks, boost::ref(system), "Bound Test")), "do_callbacks");
+
+  //Call bound version of do_callbacks
+  chai.evaluate_string("do_callbacks()");
+
+}
+