There are a large number of built-in functions available for use by MOO programmers. Each one is discussed in detail in this section. The presentation is broken up into subsections by grouping together functions with similar or related uses.
For most functions, the expected types of the arguments are given; if the
actual arguments are not of these types, E_TYPE is raised. Some
arguments can be of any type at all; in such cases, no type specification is
given for the argument. Also, for most functions, the type of the result of
the function is given. Some functions do not return a useful result; in such
cases, the specification `none' is used. A few functions can potentially
return any type of value at all; in such cases, the specification `value'
is used.
Most functions take a certain fixed number of required arguments and, in some
cases, one or two optional arguments. If a function is called with too many or
too few arguments, E_ARGS is raised.
Functions are always called by the program for some verb; that program is
running with the permissions of some player, usually the owner of the verb in
question (it is not always the owner, though; wizards can use
set_task_perms() to change the permissions `on the fly'). In the
function descriptions below, we refer to the player whose permissions are being
used as the programmer.
Many built-in functions are described below as raising E_PERM unless
the programmer meets certain specified criteria. It is possible to restrict
use of any function, however, so that only wizards can use it; see the chapter
on server assumptions about the database for details.