@cwola/limited-size-stack v1.1.6
limited-size-stack
Providing limited size stack for JS (& TypeScript).
Overview
Providing limited size stack for JS (& TypeScript).
Installation
$ npm i --save @cwola/limited-size-stackUsage
import {
Stack,
ROTATE
} from '@cwola/limited-size-stack';
const STACK = new Stack(/* capacity = */ 5);
STACK.push('one', 'two', 'three', 'four', 'five');
// STACK : ['one', 'two', 'three', 'four', 'five']
STACK.push('six');
// STACK : ['two', 'three', 'four', 'five', 'six']
console.log(STACK.top());
// output : 'six'
STACK.rotate(ROTATE.RIGHT);
// STACK : ['six', 'two', 'three', 'four', 'five']
STACK.dup();
// STACK : ['two', 'three', 'four', 'five', 'five']Method
constructor
Description
Constructor
Arguments
Name Type Description capacity number The maximum capacity of the stack.If you specify a negative number, the capacity is unlimited. Return
Type Description Stack Stack instance.
push
Description
Push one or more elements onto the end of stack, removing the oldest element if the stack is full.
Arguments
Name Type Description ...elements any[] input elements. Return
Type Description number The new number of elements in the stack. example
const stack = new Stack(3); stack.push('one', 'two'); // returns 2 // stack : ['one', 'two'] stack.push('three'); // returns 3 // stack : ['one', 'two', 'three'] stack.push('four'); // returns 3 // stack : ['two', 'three', 'four']
pop
Description
Pop the element off the end of stack.
Arguments
Name Type Description Return
Type Description any Returns the last element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] tack.pop(); // returns 'three' // stack : ['one', 'two']
shift
Description
Shift an element off the beginning of stack.
Arguments
Name Type Description Return
Type Description any Returns the shifted element.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.shift(); // returns 'one' // stack : ['two', 'three']
top
Description
Returns the last element of stack. The topmost element is returned, but the stack size does not change (meaning the element remains on the stack).
Arguments
Name Type Description Return
Type Description any Returns the last element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.top(); // returns 'three' // stack : ['one', 'two', 'three']
bottom
Description
Returns the first element of stack. The bottom element is returned, but the stack size does not change (meaning the element remains on the stack).
Arguments
Name Type Description Return
Type Description any Returns the first element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.bottom(); // returns 'one' // stack : ['one', 'two', 'three']
at
Description
Takes an integer value and returns the element at that index. Supports relative indexing from the end of the stack when passed a negative index. i.e. if a negative number is used, the element returned will be found by counting back from the end of the stack.
Arguments
Name Type Description index number The index (position) of the stack element to be returned. Return
Type Description any Returns the element in the stack matching the given index.If stack is empty or index is out of bounds, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.at(1); // returns 'two' // stack : ['one', 'two', 'three'] stack.at(-1); // returns 'three' // stack : ['one', 'two', 'three']
dup
Description
The top element is popped, and then pushed again (twice). so that an additional copy of the former top element is now on top, with the original below it.
Arguments
Name Type Description Return
Type Description any Returns the last element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.dup(); // returns 'three' // stack : ['two', 'three', 'three']
swap
Description
Swap the two positions of the topmost elements on the stack.
Arguments
Name Type Description Return
Type Description any Returns the last element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.swap(); // returns 'two' // stack : ['one', 'three', 'two']
rotate
Description
Rotate the topmost n items to move on the stack. The n topmost items are moved on the stack in a rotating fashion. 'n' is the number of elements to rotate (but if you specify '0' or negative number, the target will be all elements). so, if you specify '2', it becomes 'swap'. Two variants of this operation are possible, left rotate and right rotate.
Arguments
Name Type Description direction ROTATE ROTATE.RIGHT or ROTATE.LEFT n number number of elements to rotateoptional default : 0 Return
Type Description any Returns the last element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.rotate(ROTATE.RIGHT); // returns 'two' // stack : ['three', 'one', 'two'] stack.rotate(ROTATE.LEFT); // returns 'three' // stack : ['one', 'two', 'three']
reverse
Description
Reverse the order of the elements on stack.
Arguments
Name Type Description Return
Type Description any Returns the last element of stack.If stack is empty, 'undefined' will be returned. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.reverse(); // returns 'one' // stack : ['three', 'two', 'one']
size
Description
Get number of elements.
Arguments
Name Type Description Return
Type Description number Number of elements. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.size(); // returns 3 // stack : ['one', 'two', 'three']
isEmpty
Description
Returns True if the stack is empty, false otherwise.
Arguments
Name Type Description Return
Type Description Boolean Returns True if the stack is empty, false otherwise. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.isEmpty(); // returns False // stack : ['one', 'two', 'three'] stack.clear(); stack.isEmpty; // returns True // stack : []
clear
Description
Clear all elements.
Arguments
Name Type Description Return
Type Description this this. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] stack.clear(); // returns stack // stack : []
clone
Description
Clone this stack. The stack property is shallow-copied.
Arguments
Name Type Description Return
Type Description Stack new Stack instance. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] const copied = stack.clone(); stack.push('four'); // stack : ['two', 'three', 'four'] // copied : ['one', 'two', 'three']
toArray
Description
To array (shallow-copied).
Arguments
Name Type Description Return
Type Description any[] array. example
const stack = new Stack(3); stack.push('one', 'two', 'three'); // stack : ['one', 'two', 'three'] const arr = stack.toArray(); stack.push('four'); // stack : ['two', 'three', 'four'] // arr : ['one', 'two', 'three']