Struct scriptful::core::stack::Stack

pub struct Stack<Val = Value> where
    Val: Debug, { /* private fields */ }

An ordered sequence of values that can be operated in a LIFO-alike way.

Every Stack actually comprises two sequences of values: the main sub-stack and the alt sub-stack.

As its name indicates, the main sub-stack is the one you operate by default. That is, the alt sub-stack cannot be operated directly — you can only move values between both sub-stacks with the pop_into_alt and push_from_alt methods. The alt sub-stack is therefore limited for usage as a sort of clipboard for values.

Implementations

impl<Val> Stack<Val> where
    Val: Debug, 

pub fn length(&self) -> usize

Returns the number of values in the main sub-stack, also referred to as its ‘length’.

Examples

use scriptful::prelude::*;
use scriptful::core::value::Value::*;

let mut stack = Stack::default();
assert_eq!(stack.length(), 0);

stack.push(Integer(i128::default()));
assert_eq!(stack.length(), 1);

stack.pop();
assert_eq!(stack.length(), 0);

pub fn pop(&mut self) -> Option<Val>

Removes the topmost value in the main sub-stack and returns it.

Examples

use scriptful::prelude::*;
use scriptful::core::value::Value::*;

let value = Integer(i128::default());
let mut stack = Stack::default();
stack.push(value.clone());
let popped = stack.pop();

assert_eq!(value, popped);

pub fn pop_into_alt(&mut self)

Similar to pop, but instead of returning the popped value, it pushes it to the alt sub-stack.

Panics

Panics if there are no values left in the main stack.

pub fn push(&mut self, item: Val)

Puts a value on top of the stack.

Examples

use scriptful::prelude::*;
use scriptful::core::value::Value::*;

let value = Integer(i128::default());
let mut stack = Stack::default();
stack.push(value.clone());
let topmost = stack.topmost();

assert_eq!(topmost, Some(&value));

pub fn push_from_alt(&mut self)

Similar to push, but instead of receiving the value to be pushed as an argument, it pops it from the alt sub-stack.

pub fn topmost(&self) -> Option<&Val>

Returns a reference to the last value in the main sub-stack.

Examples

use scriptful::prelude::*;
use scriptful::core::value::Value::*;

let value = Integer(i128::default());
let mut stack = Stack::default();
stack.push(value.clone());
let topmost = stack.topmost();

assert_eq!(topmost, Some(&value));

Trait Implementations

impl<Val: Debug> Debug for Stack<Val> where
    Val: Debug, 

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<Val> Default for Stack<Val> where
    Val: Debug, 

fn default() -> Self

Returns the “default value” for a type.