extract ¶Use the extract command in order to create a temporary
memory IO space with the contents of a mapped value.
This command has the following synopsis.
extract :val val [:to ios_name]
Where :val is a mapped value, and :to is the name of the
memory IOS to create (or use). The contents of value are copied
to the beginning of the memory IOS *ios_name*.
If no :to argument is specified, or if it is the empty string,
then the extract command will generate a suitable unique
name and use it.