devela/data/list/stack/
adt.rs

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1// devela::data::collections::traits::stacks
2//
3//! Defines the [`DataStack`] & [`DataDesta`] abstract data types.
4//
5// TOC
6// - define traits DataStack, DataDesta
7// - impl for
8//   - VecDeque
9
10#![allow(dead_code, reason = "feature-gated implementations")]
11
12use crate::{DataCollection, NotEnoughElements, NotEnoughSpace};
13
14#[doc = crate::TAG_DATA_STRUCTURE!()]
15/// An abstract *stack* data type.
16pub trait DataStack: DataCollection {
17    /// Remove an element from the (back of the) stack.
18    fn stack_pop(&mut self) -> Result<<Self as DataCollection>::Element, NotEnoughElements>;
19    /// Add an element to the (back of the) stack.
20    fn stack_push(
21        &mut self,
22        element: <Self as DataCollection>::Element,
23    ) -> Result<(), NotEnoughSpace>;
24}
25
26#[doc = crate::TAG_DATA_STRUCTURE!()]
27/// An abstract *double-ended stack* data type.
28pub trait DataDesta: DataStack {
29    /// Remove an element from the front of the stack.
30    fn stack_pop_front(&mut self) -> Result<<Self as DataCollection>::Element, NotEnoughElements>;
31    /// Add an element to the front of the stack.
32    fn stack_push_front(
33        &mut self,
34        element: <Self as DataCollection>::Element,
35    ) -> Result<(), NotEnoughSpace>;
36
37    /// Remove an element from the back of the stack (calls [`DataStack::stack_pop`]).
38    fn stack_pop_back(&mut self) -> Result<<Self as DataCollection>::Element, NotEnoughElements> {
39        self.stack_pop()
40    }
41    /// Remove an element from the back of the stack (calls [`DataStack::stack_push`]).
42    ///
43    fn stack_push_back(
44        &mut self,
45        element: <Self as DataCollection>::Element,
46    ) -> Result<(), NotEnoughSpace> {
47        self.stack_push(element)
48    }
49}
50
51/* impl for VecDeque */
52
53#[rustfmt::skip]
54#[cfg(feature = "alloc")]
55impl<T> DataStack for crate::VecDeque<T> {
56    fn stack_pop(&mut self) -> Result<<Self as DataCollection>::Element, NotEnoughElements> {
57        self.pop_back().ok_or(NotEnoughElements(Some(1)))
58    }
59    fn stack_push(&mut self, element: <Self as DataCollection>::Element) -> Result<(), NotEnoughSpace> {
60        self.push_back(element); Ok(())
61    }
62}
63#[rustfmt::skip]
64#[cfg(feature = "alloc")]
65impl<T> DataDesta for crate::VecDeque<T> {
66    fn stack_pop_front(&mut self) -> Result<<Self as DataCollection>::Element, NotEnoughElements> {
67        self.pop_front().ok_or(NotEnoughElements(Some(1)))
68    }
69    fn stack_push_front(&mut self, element: <Self as DataCollection>::Element) -> Result<(), NotEnoughSpace> {
70        self.push_front(element); Ok(())
71    }
72}
devela/data/list/stack/adt.rs

devela/data/list/stack/
adt.rs
