Better logging function

Now it is possible to provide some data together with the logging function.
This is useful for example in C++, where I can now provide an arbitrary
callable object as data, and a simple wrapper function that call the
callable object as logging function.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/nissy.h b/src/nissy.h
index 816e03a..b13f417 100644
--- a/src/nissy.h
+++ b/src/nissy.h
@@ -421,7 +421,11 @@ Set a global logger function used by this library. Setting the logger to NULL
 disables logging.
 
 Parameters:
-   write - A callback writer with the same signature as printf(3).
+   logger_function - A pointer to a function that takes two parameters:
+                     * A C string, the string to be printed.
+                     * Any other data via a void pointer.
+   user_data       - Any data that will be provided by the logger when
+                     calling logger_function.
 
 Return values:
    NISSY_OK - Logger set succesfully. No warning or error is going to be given
@@ -429,5 +433,6 @@ Return values:
 */
 long long
 nissy_setlogger(
-        void (*logger_function)(const char *)
+        void (*logger_function)(const char *, void *),
+        void *user_data
 );