retroforth/doc/book/techniques/pointers

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# Working With Pointers
## Sigil
Pointers are returned by the `&` sigil.
## Examples
```
'Base var
&Base fetch
#10 &Base store
#10 &n:inc call
```
## Notes
The use of `&` to get a pointer to a data structure (with a
word class of `class:data`) is not required. I like to use it
anyway as it makes my intent a little clearer.
Pointers are useful with combinators. Consider:
```
:abs dup n:negative? [ n:negate ] if ;
```
Since the target quote body is a single word, it is more
efficient to use a pointer instead:
```
:abs dup n:negative? &n:negate if ;
```
The advantages are speed (saves a level of call/return by
avoiding the quotation) and size (for the same reason).
This may be less readable though, so consider the balance
of performance to readability when using this approach.