added support for passing function pointers as well as native lua object

into wrappered function
added example funcptr3


git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@9264 626c5289-ae23-0410-ae9c-e8d60b6d4f22

SWIG/Examples/lua/funcptr3/.cvsignore

@@ -0,0 +1,13 @@
+example.py
+example.pyc
+*_wrap.c
+*_wrap.cxx
+*.dll
+*.dsw
+*.exp
+*.lib
+*.ncb
+*.opt
+*.plg
+Release
+Debug

SWIG/Examples/lua/funcptr3/Makefile

@@ -0,0 +1,19 @@
+TOP        = ../..
+SWIG       = $(TOP)/../preinst-swig
+CXXSRCS    = example.c
+TARGET     = example
+INTERFACE  = example.i
+LIBS       = 
+
+all::
+	$(MAKE) -f $(TOP)/Makefile CXXSRCS='$(CXXSRCS)' SWIG='$(SWIG)' \
+	TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' lua
+
+static::
+	$(MAKE) -f $(TOP)/Makefile CXXSRCS='$(CXXSRCS)' SWIG='$(SWIG)' \
+	TARGET='mylua' INTERFACE='$(INTERFACE)' lua_static
+
+clean::
+	$(MAKE) -f $(TOP)/Makefile lua_clean
+
+check: all

SWIG/Examples/lua/funcptr3/example.c

@@ -0,0 +1,19 @@
+/* File : example.c */
+
+int do_op(int a, int b, int (*op)(int,int)) {
+  return (*op)(a,b);
+}
+
+int add(int a, int b) {
+  return a+b;
+}
+
+int sub(int a, int b) {
+  return a-b;
+}
+
+int mul(int a, int b) {
+  return a*b;
+}
+
+int (*funcvar)(int,int) = add;

SWIG/Examples/lua/funcptr3/example.h

@@ -0,0 +1,9 @@
+/* file: example.h */
+
+extern int do_op(int,int, int (*op)(int,int));
+extern int add(int,int);
+extern int sub(int,int);
+extern int mul(int,int);
+
+extern int (*funcvar)(int,int);
+

SWIG/Examples/lua/funcptr3/example.i

@@ -0,0 +1,69 @@
+/* File : example.i */
+/*
+This demonstrates how to pass a lua function, into some C code and then call it.
+
+There are two examples, the first is as a parameter, the second as a global variable.
+
+*/
+%module example
+%{
+#include "example.h"
+%}
+/* the extra wrappers for lua functions, see SWIG/Lib/lua/lua_fnptr.i for more details */
+%include "lua_fnptr.i"
+
+/* these are a bunch of C functions which we want to be able to call from lua */
+extern int add(int,int);
+extern int sub(int,int);
+extern int mul(int,int);
+
+/* this function takes a lua function as a parameter and calls it.
+As this is takes a lua fn it needs lua code
+*/
+%inline %{
+	
+int callback(int a, int b, SWIGLUA_FN fn)
+{
+	SWIGLUA_FN_GET(fn);
+	lua_pushnumber(fn.L,a);
+	lua_pushnumber(fn.L,b);
+	lua_call(fn.L,2,1);    /* 2 in, 1 out */
+	return luaL_checknumber(fn.L,-1);
+}	
+%}	
+
+/******************
+Second code uses a stored reference.
+*******************/
+
+%inline %{
+/* note: this is not so good to just have it as a raw ref
+ people could set anything to this
+ a better solution would to be to have a fn which wants a SWIGLUA_FN, then
+ checks the type & converts to a SWIGLUA_REF.
+*/	
+SWIGLUA_REF the_func={0,0};
+	
+void call_the_func(int a)
+{
+	int i;
+	if (the_func.L==0){
+		printf("the_func is zero\n");
+		return;
+	}
+	swiglua_ref_get(&the_func);
+	if (!lua_isfunction(the_func.L,-1))
+	{
+		printf("the_func is not a function\n");
+		return;
+	}
+	lua_pop(the_func.L,1); /* tidy stack */
+	for(i=0;i<a;i++)
+	{
+		swiglua_ref_get(&the_func);
+		lua_pushnumber(the_func.L,i);
+		lua_call(the_func.L,1,0);    /* 1 in, 0 out */
+	}
+}	
+
+%}

SWIG/Examples/lua/funcptr3/runme.lua

@@ -0,0 +1,54 @@
+---- importing ----
+if string.sub(_VERSION,1,7)=='Lua 5.0' then
+	-- lua5.0 doesnt have a nice way to do this
+	lib=loadlib('example.dll','Example_Init') or loadlib('example.so','Example_Init')
+	assert(lib)()
+else
+	-- lua 5.1 does
+	require('example')
+end
+
+a = 37
+b = 42
+
+-- Now call our C function
+
+print("Trying some C functions")
+print("    a        =", a)
+print("    b        =", b)
+print("    add(a,b) =", example.add(a,b))
+print("    sub(a,b) =", example.sub(a,b))
+print("    mul(a,b) =", example.mul(a,b))
+
+print("Calling them using the my_func()")
+print("    add(a,b) =", example.callback(a,b,example.add))
+print("    sub(a,b) =", example.callback(a,b,example.sub))
+print("    mul(a,b) =", example.callback(a,b,example.mul))
+
+print("Now let us write our own function")
+function foo(a,b) return 101 end
+print("    foo(a,b) =", example.callback(a,b,foo))
+
+print("Now let us try something that will fail")
+local ok,c=pcall(example.callback,a,b,print)
+if ok==false then
+	print("this failed as expected, error:",c)
+else
+	print("oops, that worked! result:",c)
+end
+
+
+-- part2 stored function
+print("trying a stored fn")
+print("the_func=",example.the_func)
+print("setting to print")
+example.the_func=print
+print("the_func=",example.the_func)
+print("call_the_func(5)")
+example.call_the_func(5)
+
+function bar(i) print("bar",i) end
+print("setting to bar")
+example.the_func=bar
+print("call_the_func(5)")
+example.call_the_func(5)