45 lines
996 B
Text
45 lines
996 B
Text
use Any
|
|
use Boolean
|
|
use Option
|
|
use Outrun.Core.Some, as: Some
|
|
use Outrun.Core.None, as: None
|
|
use LogicalNot
|
|
|
|
```doc
|
|
# Option
|
|
|
|
The optional type.
|
|
|
|
An option is anything that an optionally provide a value. Most commonly this will be in the shape of the `Outrun.Core.Option` enum.
|
|
```
|
|
|
|
protocol Option, as: do
|
|
```doc
|
|
Returns true if the `Option` can provide a value, false otherwise.
|
|
|
|
Must be implemented.
|
|
```
|
|
def some?(option: Self): Boolean
|
|
|
|
```doc
|
|
Returns the value of the option, or raises an error if it can not.
|
|
|
|
Must be implemented.
|
|
```
|
|
def unwrap(option: Self): Any
|
|
|
|
```doc
|
|
Returns true if the `Option` cannot provide a value, false otherwise.
|
|
```
|
|
def none?(option: Self): Boolean, as: LogicalNot.not(Option.some?(option))
|
|
|
|
```doc
|
|
Create a new "some" value using the default some type.
|
|
```
|
|
def some(value: Any): Option, as: Some.new(value)
|
|
|
|
```doc
|
|
Create a new "none" value using the default none type.
|
|
```
|
|
def none(): Option, as: None.new()
|
|
end
|