Important: The requires command has been deprecated.

The procedure requires is used to assert a load time dependency in a Maple library source file.

If any of the arguments passed to requires are not of type procedure or of type table, then an error is signalled. Otherwise, NULL is returned.

The purpose of this routine is to force an error to be generated if an attempt is made to load a file that depends, at load time, on some library routines that are not yet loaded into the repository.

$\mathrm{requires}\left(\mathrm{int}\right)$

Error, (in requires) load time requirement for int not satisfied

$\mathrm{requires}\left(\mathrm{crazy\_nonexistent\_function\_or\_table}\right)$

Error, (in requires) load time requirement for crazy_nonexistent_function_or_table not satisfied