| 2 | // LIST // |
| 3 | //======// |
| 4 | export class LinkedList { |
| 5 | constructor(iterable = []) { |
| 6 | this.start = undefined; |
| 7 | this.end = undefined; |
| 8 | this.isEmpty = true; |
| 9 | |
| 10 | for (const item of iterable) { |
| 11 | this.push(item); |
| 12 | } |
| 13 | } |
| 14 | |
| 15 | *[Symbol.iterator]() { |
| 16 | let link = this.start; |
| 17 | while (link !== undefined) { |
| 18 | yield link; |
| 19 | link = link.next; |
| 20 | } |
| 21 | } |
| 22 | |
| 23 | push(item) { |
| 24 | const link = makeLink(item); |
| 25 | if (this.isEmpty) { |
| 26 | this.start = link; |
| 27 | this.end = link; |
| 28 | this.isEmpty = false; |
| 29 | } else { |
| 30 | this.end.next = link; |
| 31 | link.previous = this.end; |
| 32 | this.end = link; |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | pop() { |
| 37 | if (this.isEmpty) { |
| 38 | return undefined; |
| 39 | } |
| 40 | |
| 41 | const item = this.start.item; |
| 42 | if (this.start === this.end) { |
| 43 | this.clear(); |
| 44 | return item; |
| 45 | } |
| 46 | |
| 47 | this.end = this.end.previous; |
| 48 | this.end.next = undefined; |
| 49 | return item; |
| 50 | } |
| 51 | |
| 52 | shift() { |
| 53 | if (this.isEmpty) { |
| 54 | return undefined; |
| 55 | } |
| 56 | |
| 57 | const item = this.start.item; |
| 58 | if (this.start === this.end) { |
| 59 | this.clear(); |
| 60 | return item; |
| 61 | } |
nothing calls this directly
no outgoing calls
no test coverage detected