5 files changed, 31 insertions, 7 deletions
diff --git a/CleanC.dcl b/CleanC.dcl
index a385a50..d0257c6 100644
--- a/CleanC.dcl
+++ b/CleanC.dcl
@@ -23,12 +23,16 @@ SOFTWARE. */
 definition module CleanC
 
 from StdClass import class toInt, class toString, class toReal,
-                     class fromInt, class fromString, class fromReal
+                     class fromInt, class fromString, class fromReal,
+                     class ==
 
 :: State
 
-:: CType = Int | String | Real
-:: CParam = CI Int | CS String | CR Real
+:: CType = Int | String | Real | Void
+:: CParam = CI Int | CS String | CR Real | CV
+
+instance == CType
+instance == CParam
 
 cNewState :: *State
 
diff --git a/CleanC.icl b/CleanC.icl
index ed1f6b1..1e1e8ce 100644
--- a/CleanC.icl
+++ b/CleanC.icl
@@ -28,6 +28,9 @@ from GenEq import generic gEq
 :: State :== Int
 
 derive gEq CType
+derive gEq CParam
+instance == CType where (==) x y = gEq{|*|} x y
+instance == CParam where (==) x y = gEq{|*|} x y
 
 cNewState :: *State
 cNewState = 42
@@ -99,6 +102,7 @@ cSetReturnType :: !CType -> *State -> *State
 cSetReturnType Int = cSetReturnType_ 0
 cSetReturnType String = cSetReturnType_ 1
 cSetReturnType Real = cSetReturnType_ 2
+cSetReturnType Void = cSetReturnType_ 3
 
 cCall_ :: !String !*State -> *State
 cCall_ f s = code inline {
@@ -138,7 +142,8 @@ where
     cCall` t f [] s
     # s = cSetReturnType t s
     # s = cCall_ f s
-    = cGetParam t s
+    | t == Void = (CV, s)
+    | otherwise = cGetParam t s
     cCall` t f [p:ps] s
     # s = cPutParam p s
     = cCall` t f ps s
diff --git a/interface.c b/interface.c
index 2a9a106..e40ed86 100644
--- a/interface.c
+++ b/interface.c
@@ -68,17 +68,21 @@ void cleanPutr(double r) {
 void cleanSetReturnType(long i) {
     switch (i) {
         case 0: 
-            return_type = &ffi_type_slong; 
+            return_type = &ffi_type_slong;
             return_val = calloc(sizeof(long), 1);
             break;
         case 1: 
-            return_type = &ffi_type_pointer; 
+            return_type = &ffi_type_pointer;
             return_val = calloc(sizeof(char*), 1);
             break;
         case 2: 
-            return_type = &ffi_type_double; 
+            return_type = &ffi_type_double;
             return_val = calloc(sizeof(double), 1);
             break;
+        case 3:
+            return_type = &ffi_type_void;
+            return_val = calloc(sizeof(void), 1);
+            break;
     }
 }
 
diff --git a/test.c b/test.c
index 9653d96..0396e7b 100644
--- a/test.c
+++ b/test.c
@@ -22,6 +22,7 @@ SOFTWARE. */
 
 #include <stdlib.h>
 #include <string.h>
+#include <stdio.h>
 
 double test_double(double x) {
     return x * 0.5;
@@ -45,3 +46,7 @@ int test_two_params(int a, int b) {
     return a + b;
 }
 
+void test_void(char* s) {
+    printf("%s", s);
+}
+
diff --git a/test.icl b/test.icl
index a452945..de40c75 100644
--- a/test.icl
+++ b/test.icl
@@ -33,6 +33,7 @@ Start w
 # (t1,s) = test_string s
 # (t2,s) = test_double s
 # (t3,s) = test_two_params s
+# (t4,s) = test_void s
 # tests = [t0,t1,t2,t3]
 # passed = and tests
 # (io, w) = stdio w
@@ -74,3 +75,8 @@ test_two_params s
 # (i, s) = cCall Int "test_two_params" (13,29) s
 = (fromCParam i == 42, s)
 
+test_void :: *State -> (Bool, *State)
+test_void s
+# (i, s) = cCall Void "test_void" "Testing void function\n" s
+= (i == CV, s)
+