Gforth Manual
5.9.8.2 The gory details of CREATE..DOES>
doc-does>
This means that you need not use CREATE and DOES> in the
same definition; you can put the DOES>-part in a separate
definition. This allows us to, e.g., select among different DOES>-parts:
| | : does1
DOES> ( ... -- ... )
... ;
: does2
DOES> ( ... -- ... )
... ;
: def-word ( ... -- ... )
create ...
IF
does1
ELSE
does2
ENDIF ;
|
In this example, the selection of whether to use does1 or
does2 is made at definition-time; at the time that the child word is
CREATEd.
In a standard program you can apply a DOES>-part only if the last
word was defined with CREATE. In Gforth, the DOES>-part
will override the behaviour of the last word defined in any case. In a
standard program, you can use DOES> only in a colon
definition. In Gforth, you can also use it in interpretation state, in a
kind of one-shot mode; for example:
| | CREATE name ( ... -- ... )
initialization
DOES>
code ;
|
is equivalent to the standard:
| | :noname
DOES>
code ;
CREATE name EXECUTE ( ... -- ... )
initialization
|
doc->body
