39 lines
797 B
Text
39 lines
797 B
Text
# 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.
|