@node Overload, Page, Notation, Commands

@iftex
@syntax Overload.
@end iftex
@example
Syntax: OVERLOAD keyword INTEGER
@end example
@pindex Overload

   Allow ``keyword'' (in lowercase) to be used as a macro name if
integer is non-zero. For example,
@example
overload set 1 overload define 1
macro set @{ DEFINE @} macro define @{ SET @}
@end example
@noindent
would interchange the
meanings of the SET and DEFINE commands. The uppercase forms
of the keywords retain their usual meanings. @code{overload set 0}
would reinstate the usual meaning of set. You may be surprised by the
effects of overloading certain keywords. For example, if you overload
@code{help} to mean @code{DELETE HISTORY HELP}, then @code{set help vec
help_string} won't work (you'd have to say @code{set HELP vec @dots{}}).

   This command is intended to be used for changing the default action of
commands, rather than for a wholesale renaming of keywords! A more practical
example than the above would be
@example
overload erase 1 macro erase @{ del1 ERASE @}
@end example
@noindent
to prevent erase commands from appearing on the history list. See the
macro @code{set_overload} for a set of definitions like this. It can
be automatically executed by including an ``overload'' line on your
@file{.sm} file.