The type-in module is the module that is taken as the source
module for goals typed in by the user. The name of the default
type-in module is user
. That is, the predicates that are available
to be called directly by the user are those that are visible in the
module user
.
When debugging, it is often useful to call, directly from the top-level,
predicates that are private to a module, or predicates that are public but
that are not imported into user
. This can be done by prefixing each
goal with the module name, as described in ref-mod-vis;
but rather than doing this extensively, it may be more convenient to make this module the
type-in module.
The type-in module can be changed using the built-in predicate
set_module/1
; for example,
| ?- set_module(mod).
This command will cause subsequent goals typed at the top-level to be
executed with mod
as their source module.
The name of the type-in module is always displayed, except when it
is user
. If you are running Prolog under the editor interface,
the type-in
module is displayed in the status line of the Prolog window. If you are
running Prolog without the editor interface, the type-in module is displayed
before each top-level prompt.
For example, if you are running Prolog without the editor:
| ?- module(foo). yes [foo] | ?-
It should be noted that it is unlikely to be useful to change the type-in module via a directive embedded in a file to be loaded, because this will have no effect on the load—it will only change the type-in module for commands subsequently entered by the user.