feedthecommunity.co.uk/node_modules/@blakeembrey/deque/dist/index.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
class Deque {
    constructor(values) {
        this.head = 0;
        this.tail = 0;
        this.mask = 1;
        this.list = new Array(2);
        if (values)
            this.extend(values);
    }
    _resize(size, length) {
        const { head, mask } = this;
        this.head = 0;
        this.tail = size;
        this.mask = length - 1;
        // Optimize resize when list is already sorted.
        if (head === 0) {
            this.list.length = length;
            return;
        }
        const sorted = new Array(length);
        for (let i = 0; i < size; i++)
            sorted[i] = this.list[(head + i) & mask];
        this.list = sorted;
    }
    push(value) {
        this.list[this.tail] = value;
        this.tail = (this.tail + 1) & this.mask;
        if (this.head === this.tail)
            this._resize(this.list.length, this.list.length << 1);
        return this;
    }
    pushLeft(value) {
        this.head = (this.head - 1) & this.mask;
        this.list[this.head] = value;
        if (this.head === this.tail)
            this._resize(this.list.length, this.list.length << 1);
        return this;
    }
    clear() {
        this.head = 0;
        this.tail = 0;
    }
    extend(values) {
        for (const value of values)
            this.push(value);
        return this;
    }
    extendLeft(values) {
        for (const value of values)
            this.pushLeft(value);
        return this;
    }
    peek(index) {
        const { head, size, tail, list } = this;
        if ((index | 0) !== index || index >= size || index < -size) {
            throw new RangeError('deque index out of range');
        }
        const pos = ((index >= 0 ? head : tail) + index) & this.mask;
        return list[pos];
    }
    indexOf(needle, start = 0) {
        const { head, list, size, mask } = this;
        const offset = start >= 0 ? start : start < -size ? 0 : size + start;
        for (let i = offset; i < size; i++) {
            if (list[(head + i) & mask] === needle)
                return i;
        }
        return -1;
    }
    has(needle) {
        const { head, list, size, mask } = this;
        for (let i = 0; i < size; i++) {
            if (list[(head + i) & mask] === needle)
                return true;
        }
        return false;
    }
    insert(index, value) {
        const pos = (this.head + index) & this.mask;
        let cur = this.tail;
        // Increase tail position by 1.
        this.tail = (this.tail + 1) & this.mask;
        // Shift items forward 1 to make space for insert.
        while (cur !== pos) {
            const prev = (cur - 1) & this.mask;
            this.list[cur] = this.list[prev];
            cur = prev;
        }
        this.list[pos] = value;
        if (this.head === this.tail)
            this._resize(this.list.length, this.list.length << 1);
        return this;
    }
    get size() {
        return (this.tail - this.head) & this.mask;
    }
    pop() {
        if (this.head === this.tail)
            throw new RangeError('pop from an empty deque');
        this.tail = (this.tail - 1) & this.mask;
        const value = this.list[this.tail];
        this.list[this.tail] = undefined;
        if (this.size < this.mask >>> 1)
            this._resize(this.size, this.list.length >>> 1);
        return value;
    }
    popLeft() {
        if (this.head === this.tail)
            throw new RangeError('pop from an empty deque');
        const value = this.list[this.head];
        this.list[this.head] = undefined;
        this.head = (this.head + 1) & this.mask;
        if (this.size < this.mask >>> 1)
            this._resize(this.size, this.list.length >>> 1);
        return value;
    }
    delete(index) {
        if (index >= this.size || index < 0) {
            throw new RangeError('deque index out of range');
        }
        const pos = (this.head + index) & this.mask;
        let cur = pos;
        // Shift items backward 1 to erase position.
        while (cur !== this.tail) {
            const next = (cur + 1) & this.mask;
            this.list[cur] = this.list[next];
            cur = next;
        }
        // Decrease tail position by 1.
        this.tail = (this.tail - 1) & this.mask;
        if (this.size < this.mask >>> 1)
            this._resize(this.size, this.list.length >>> 1);
        return this;
    }
    reverse() {
        const { head, tail, size, mask } = this;
        for (let i = 0; i < ~~(size / 2); i++) {
            const a = (tail - i - 1) & mask;
            const b = (head + i) & mask;
            const temp = this.list[a];
            this.list[a] = this.list[b];
            this.list[b] = temp;
        }
        return this;
    }
    rotate(n = 1) {
        const { head, tail } = this;
        if (n === 0 || head === tail)
            return this;
        this.head = (head - n) & this.mask;
        this.tail = (tail - n) & this.mask;
        if (n > 0) {
            for (let i = 1; i <= n; i++) {
                const a = (head - i) & this.mask;
                const b = (tail - i) & this.mask;
                this.list[a] = this.list[b];
                this.list[b] = undefined;
            }
        }
        else {
            for (let i = 0; i > n; i--) {
                const a = (tail - i) & this.mask;
                const b = (head - i) & this.mask;
                this.list[a] = this.list[b];
                this.list[b] = undefined;
            }
        }
        return this;
    }
    *entries() {
        const { head, size, list, mask } = this;
        for (let i = 0; i < size; i++)
            yield list[(head + i) & mask];
    }
    keys() {
        return this.entries();
    }
    values() {
        return this.entries();
    }
    [Symbol.iterator]() {
        return this.entries();
    }
}
exports.Deque = Deque;
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