libguile-ssh/common.c (compare_objects): New procedure

* libguile-ssh/common.c (compare_objects): New procedure.
* libguile-ssh/common.h: Update.
* libguile-ssh/channel-func.c (equalp_channel): Use the new procedure.

Author: artyom-poptsov

libguile-ssh/channel-func.c

@@ -75,15 +75,7 @@ Return #t if X is a SSH channel, #f otherwise.\
 SCM
 equalp_channel (SCM x1, SCM x2)
 {
-    gssh_channel_t *channel1 = gssh_channel_from_scm (x1);
-    gssh_channel_t *channel2 = gssh_channel_from_scm (x2);
-
-    if ((! channel1) || (! channel2))
-        return SCM_BOOL_F;
-    else if (channel1 != channel2)
-        return SCM_BOOL_F;
-    else
-        return SCM_BOOL_T;
+    return compare_objects(x1, x2, gssh_channel_from_scm);
 }
 #endif
 

libguile-ssh/common.c

@@ -79,4 +79,21 @@ set_smob_callbacks(scm_t_bits tag,
     scm_set_smob_equalp(tag, equalp_cb);
 }
 
+
+/** Procedure that converts an SCM object to an Guile-UDev structure
+ * pointer.
+ */
+SCM compare_objects(SCM x1, SCM x2, converter_t converter)
+{
+    void* d1 = converter(x1);
+    void* d2 = converter(x2);
+    if ((! d1) || (! d2)) {
+        return SCM_BOOL_F;
+    } else if (d1 != d2) {
+        return SCM_BOOL_F;
+    } else {
+        return SCM_BOOL_T;
+    }
+}
+
 /* common.c ends here. */

libguile-ssh/common.h

@@ -91,6 +91,10 @@ void set_smob_callbacks(scm_t_bits tag,
                         gc_equalp_callback_t equalp_cb,
                         gc_print_callback_t  print_cb);
 
+
+typedef void* (*converter_t)(SCM x);
+SCM compare_objects(SCM x1, SCM x2, converter_t converter);
+
 #endif  /* ifndef __COMMON_H__ */
 
 /* common.h ends here. */