option.md

Standard Library: Option (std/option.zc)

Option<T> represents an optional value: every Option is either Some and contains a value, or None, and does not.

Usage

import "std/option.zc"

fn main() {
    let val = Option<int>::Some(10);
    
    if (val.is_some()) {
        println "{val.unwrap()}";
    }
    
    let nothing = Option<int>::None();
    println "{nothing.unwrap_or(0)}"; // Prints 0
}

Structure

struct Option<T> {
    is_some: bool;
    val: T;
}

Methods

Construction

Method	Signature	Description
Some	Option<T>::Some(v: T) -> Option<T>	Creates a Some option containing v.
None	Option<T>::None() -> Option<T>	Creates a None option.

Query / Extraction

Method	Signature	Description
is_some	is_some(self) -> bool	Returns true if the option is a Some value.
is_none	is_none(self) -> bool	Returns true if the option is a None value.
unwrap	unwrap(self) -> T	Returns the contained value. Panics if None.
unwrap_ref	unwrap_ref(self) -> T*	Returns a pointer to the contained value. Panics if None.
unwrap_or	unwrap_or(self, def: T) -> T	Returns the contained value or def if None.
expect	expect(self, msg: char*) -> T	Returns the contained value or panics with msg if None.
or_else	or_else(self, other: Option<T>) -> Option<T>	Returns the option if it contains a value, otherwise returns other.
forget	forget(self)	Zeroes out memory without destructors (if applicable).