>Original sender: "Roland Herrera" <Leonid_at_globalnet.co.uk>
>
>To more experienced Forthers than I ( hopeless beginner ! )
>Hello,
>
>what does !+ mean ? ( not +! )
>what does H mean ?
>what does OPTIONAL do exactly ?

!+ is an incrementing store.

: !+ ( addr n -- addr+4 ) OVER ! CELL+ ;

Very useful for building tables.

H is the dictionary pointer.

: HERE ( -- addr ) H @ ;

OPTIONAL is a tag which, if placed on the first line of a file

a) generates a Forth word which indicates the package is loaded
b) prevents the same file from being loaded again. Useful for
    things like random number generators and such that are "optional"
    packages which you only want to load once.
c) provides a hook (if in the correct directory) for the optional packages
    menu item to find.

Hope this helps.
Rick

.
Received on Sun Dec 27 1998 - 11:26:18 PST