evnty/build/sequence.js

0-Deps, simple, fast, for browser and node js reactive anonymous event library

import { Callable } from "./callable.js";
import { Signal } from "./signal.js";
export class Sequence extends Callable {
    abortSignal;
    sequence;
    nextSignal;
    constructor(abortSignal){
        super((value)=>{
            if (this.abortSignal?.aborted) {
                this.nextSignal(false);
                return false;
            } else {
                this.sequence.push(value);
                if (this.sequence.length === 1) {
                    this.nextSignal(true);
                }
                return true;
            }
        }), this.abortSignal = abortSignal;
        this.sequence = [];
        this.nextSignal = new Signal(this.abortSignal);
        this.abortSignal?.addEventListener('abort', ()=>{
            this.nextSignal(false);
        }, {
            once: true
        });
    }
    get [Symbol.toStringTag]() {
        return `Sequence(${this.abortSignal?.aborted ? 'stopped' : 'active'})`;
    }
    get promise() {
        return this.next();
    }
    async next() {
        if (!this.sequence.length) {
            await this.nextSignal;
        }
        return this.sequence.shift();
    }
    catch(onrejected) {
        return this.promise.catch(onrejected);
    }
    finally(onfinally) {
        return this.promise.finally(onfinally);
    }
    then(onfulfilled, onrejected) {
        return this.promise.then(onfulfilled, onrejected);
    }
    [Symbol.asyncIterator]() {
        return {
            next: async ()=>{
                try {
                    const value = await this;
                    return {
                        value,
                        done: false
                    };
                } catch  {
                    return {
                        value: undefined,
                        done: true
                    };
                }
            },
            return: ()=>{
                this.nextSignal(false);
                return Promise.resolve({
                    value: undefined,
                    done: true
                });
            }
        };
    }
}

//# sourceMappingURL=sequence.js.map