libfoundation: Implement __MCHandlerCopyDescription().

peter-b · peter-b · commit 761e354bd343 · 2015-02-10T11:31:14.000Z
Add a `describe()` callback to the `MCHandlerCallbacks` structure.  If
not provided, just describe as "&lt;handler&gt;".
diff --git a/libfoundation/include/foundation.h b/libfoundation/include/foundation.h
@@ -2479,6 +2479,7 @@ struct MCHandlerCallbacks
     size_t size;
     void (*release)(void *context);
     bool (*invoke)(void *context, MCValueRef *arguments, uindex_t argument_count, MCValueRef& r_value);
+	bool (*describe)(void *context, MCStringRef& r_desc);
 };
 
 MC_DLLEXPORT bool MCHandlerCreate(MCTypeInfoRef typeinfo, const MCHandlerCallbacks *callbacks, void *context, MCHandlerRef& r_handler);
diff --git a/libfoundation/src/foundation-handler.cpp b/libfoundation/src/foundation-handler.cpp
@@ -74,7 +74,13 @@ bool __MCHandlerIsEqualTo(__MCHandler *self, __MCHandler *other_self)
 
 bool __MCHandlerCopyDescription(__MCHandler *self, MCStringRef& r_desc)
 {
-    return false;
+	if (NULL != self->callbacks->describe)
+		return self->callbacks->describe(MCHandlerGetContext (self), r_desc);
+
+	/* Default implementation. */
+	/* FIXME Should include information about arguments and return
+	 * values, extracted from the handler's typeinfo. */
+	return MCStringCopy(MCSTR("<handler>"), r_desc);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/libfoundation/src/foundation-string.cpp b/libfoundation/src/foundation-string.cpp
@@ -757,8 +757,6 @@ bool MCStringFormatV(MCStringRef& r_string, const char *p_format, va_list p_args
                 /* UNCHECKED */ MCStringFormat(&t_string, t_value == kMCTrue ? "<true>" : "<false>");
 			else if (MCValueGetTypeCode(t_value) == kMCValueTypeCodeNull)
                 /* UNCHECKED */ MCStringFormat(&t_string, "<null>");
-            else if (MCValueGetTypeCode(t_value) == kMCValueTypeCodeHandler)
-                /* UNCHECKED */ MCStringFormat(&t_string, "<handler>");
             else
 				/* UNCHECKED */ MCValueCopyDescription (t_value, &t_string);
 

Original file line number	Diff line number	Diff line change
`@@ -74,7 +74,13 @@ bool __MCHandlerIsEqualTo(__MCHandler self, __MCHandler other_self)`
`74`	`74`
`75`	`75`	`bool __MCHandlerCopyDescription(__MCHandler *self, MCStringRef& r_desc)`
`76`	`76`	`{`
`77`		`- return false;`
	`77`	`+ if (NULL != self->callbacks->describe)`
	`78`	`+ return self->callbacks->describe(MCHandlerGetContext (self), r_desc);`
	`79`	`+`
	`80`	`+ /* Default implementation. */`
	`81`	`+ /* FIXME Should include information about arguments and return`
	`82`	`+ * values, extracted from the handler's typeinfo. */`
	`83`	`+ return MCStringCopy(MCSTR("<handler>"), r_desc);`
`78`	`84`	`}`
`79`	`85`
`80`	`86`	`////////////////////////////////////////////////////////////////////////////////`