ensure_loaded/1

Availability:built-in

ensure_loaded(:File)

If the file is not already loaded, this is equivalent to consult/1. Otherwise, if the file defines a module, import all public predicates. Finally, if the file is already loaded, is not a module file, and the context module is not the global user module, ensure_loaded/1 will call consult/1.

With this semantics, we hope to get as close as possible to the clear semantics without the presence of a module system. Applications using modules should consider using use_module/[1,2].

Equivalent to load_files(Files, [if(not_loaded)]).^{46On
older versions the condition used to be if(changed). Poor
time management on some machines or copying often caused problems. The make/0
predicate deals with updating the running system after changing the
source code.}