Struct StackCalc 

pub struct StackCalc { /* private fields */ }

A simple stack-based calculator for arithmetic expressions.

Implementations

impl StackCalc

pub fn new() -> Self

Creates a new empty calculator.

pub fn push(&mut self, n: i64)

Pushes an integer literal.

pub fn add(&mut self) -> Option<i64>

Adds the top two values and returns the sum, which replaces them. Returns None, leaving the stack unchanged, if it holds fewer than two values.

pub fn sub(&mut self) -> Option<i64>

Subtracts top from second and returns the difference, which replaces them. Returns None, leaving the stack unchanged, if it holds fewer than two values.

pub fn mul(&mut self) -> Option<i64>

Multiplies the top two values and returns the product, which replaces them. Returns None, leaving the stack unchanged, if it holds fewer than two values.

pub fn peek(&self) -> Option<i64>

Peeks the top value.

pub fn depth(&self) -> usize

Returns the stack depth.

Trait Implementations

impl Default for StackCalc

fn default() -> Self

Returns the “default value” for a type.