HELP LENGTH                                    Steven Hardy  January 78

    length(structure or list) -> integer

Given a structure, this procedure returns the number of components it
contains, for example:

    length("abcd") =>
    ** 4
    length({a b c d}) =>
    ** 4
    length('abcd') =>
    ** 4
    length([a b c d]) =>
    ** 4

Notice that LENGTH 'cheats' slightly if given a list in that since lists are
made up of a chain of two element structures (with components accessed with
HD and TL) it ought really to return 2 given any list. This would not be
useful so in this event LENGTH computes the number of elements in the list.

See also HELP * DATALENGTH, *LISTLENGTH

Since LENGTH has to test to find out what sort of argument it is given,
LISTLENGTH can be used when the argument is known to be a list. This will
be slightly more efficient.
