- module on. If @opts contains ':fatal', the module will croak on the
- first indirect syntax met.
+ module on. The policy to apply depends on what is first found in @opts :
+
+ * If it's the string ':fatal', the compilation will croak on the first
+ indirect syntax met.
+
+ * If the key/value pair "hook => $hook" comes first, $hook will be
+ called for each error with a string representation of the object as
+ $_[0], the method name as $_[1], the current file as $_[2] and the
+ line number as $_[3]. If and only if the object is actually a block,
+ $_[0] is assured to start by '{'.
+
+ * Otherwise, a warning will be emitted for each indirect construct.