[lua] updated docs for exceptions

added new examples (exception,embed2)
update typmaps

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@10300 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Lib/lua/lua.swg

@@ -15,6 +15,7 @@
 %include <luatypemaps.swg>          /* The typemaps */
 %include <luaruntime.swg>          /* The runtime stuff */
 
+//%include <typemaps/swigmacros.swg>
 /* -----------------------------------------------------------------------------
  *                          constants typemaps
  * ----------------------------------------------------------------------------- */
@@ -154,51 +155,75 @@ Therefore currently its just enough to get a few test cases running ok
 note: if you wish to throw anything related to std::exception
 use %include <std_except.i> instead
 */
+
+// number as number+error
 %typemap(throws) int,unsigned int,signed int,
 				long,unsigned long,signed long,
 				short,unsigned short,signed short,
-				bool,float,double,
+				float,double,
 				long long,unsigned long long,
-				char, unsigned char, signed char,
-				enum SWIGTYPE
-%{lua_pushfstring(L,"numeric exception:%f",(double)$1);SWIG_fail; %}
+				unsigned char, signed char,
+                int&,unsigned int&,signed int&,
+				long&,unsigned long&,signed long&,
+				short&,unsigned short&,signed short&,
+				float&,double&,
+				long long&,unsigned long long&,
+				unsigned char&, signed char&
+%{lua_pushnumber(L,(lua_Number)$1);SWIG_fail; %}
+
+%typemap(throws) bool,bool& 
+%{lua_pushboolean(L,(int)($1==true));SWIG_fail; %}
+
+// enum as number+error
+%typemap(throws) enum SWIGTYPE
+%{lua_pushnumber(L,(lua_Number)(int)$1);SWIG_fail; %}
 
 // strings are just sent as errors
 %typemap(throws) char*, const char*
 %{lua_pushstring(L,$1);SWIG_fail;%}
 
+// char is changed to a string
+%typemap(throws) char
+%{lua_pushfstring(L,"%c",$1);SWIG_fail;%}
+
 /*
 Throwing object is a serious problem:
 Assuming some code throws a 'FooBar'
 There are a few options:
 - return a pointer to it: but its unclear how long this will last for.
 - return a copy of it: but not all objects are copyable
-	(see exception_partial_info in the test suite for a case where you cannot)
+	(see exception_partial_info in the test suite for a case where you cannot do this)
 - convert to a string & throw that
 	its not so useful, but it works (this is more lua like).
 The third option (though not nice) is used
 For a more useful solution: see std_except for more details
 */
+
+// basic typemap for structs, classes, pointers & references
+// convert to string and error
 %typemap(throws) SWIGTYPE
-{
-  (void)$1;
-  lua_pushfstring(L,"object exception:%s",SWIG_TypePrettyName($1_descriptor));
-  SWIG_fail;
-}
-
-// old code: fails under exception_partial_info
-// if you have a function which throws a FooBar & you want SWIG to throw the actual object 
-// then use
-//	%apply SWIGTYPE BY_VAL {FooBar};
-%typemap(throws) SWIGTYPE BY_VAL
-{
-  SWIG_NewPointerObj(L,(void *)new $1_ltype(($1_ltype &) $1),$&1_descriptor,1);
-  SWIG_fail;
-}
-
+%{(void)$1; /* ignore it */
+lua_pushfstring(L,"object exception:%s",SWIG_TypePrettyName($1_descriptor));
+SWIG_fail;%}
 
+// code to make a copy of the object and return this
+// if you have a function which throws a FooBar & you want SWIG to return a copy of the object as its error
+// then use one of the below
+//	%apply SWIGTYPE EXCEPTION_BY_VAL {FooBar};
+//	%apply SWIGTYPE& EXCEPTION_BY_VAL {FooBar&}; // note: need & twice
+%typemap(throws) SWIGTYPE EXCEPTION_BY_VAL
+%{SWIG_NewPointerObj(L,(void *)new $1_ltype(($1_ltype &) $1),$&1_descriptor,1);
+SWIG_fail;%}
+
+// similar for object reference
+// note: swig typemaps seem a little confused around here, therefore we use $basetype
+%typemap(throws) SWIGTYPE& EXCEPTION_BY_VAL
+%{SWIG_NewPointerObj(L,(void *)new $basetype($1),$1_descriptor,1);
+SWIG_fail;%}
 
 
+// note: no support for object pointers
+// its not clear how long the pointer is valid for, therefore not supporting it
 
 /* -----------------------------------------------------------------------------
  *                          extras