sindresorhus/p-map

Allow breaking from iterator

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#31 创建于 2020年10月13日

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enhancementhelp wanted

描述

I wish I could stop the iteration early by returning something like pMap.stop (a Symbol) from the iterator.

This is basically the same request as https://github.com/sindresorhus/p-each-series/issues/3

For now, I have to throw an error on purpose just to break it. Thankfully, I don't need the return value of p-map anyway.

But with this feature, the parts of the array that weren't computed yet could be set to undefined, or pMap.uncomputed (another Symbol), or even be specified by a valueForUncomputedEarlyStop option.

Can I do a PR?

贡献者指南

技术栈
javascriptnodejs
领域
backend
议题类型
feature
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
2
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
1-3 hours
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
basic JavaScriptfamiliarity with p mapPromises
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
70
研究方向
Study the p map source code (likely index.js) to understand how the iterator callback is invoked. Implement a check for a returned Symbol (e.g., pMapBreak) that causes the loop to stop and optionally fill remaining array entries with undefined or a configurable value. Review linked issue #3 for prior discussion and consider the maintainer's feedback in the issue comments.