You can not select more than 25 topics
			Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
		
		
		
		
		
			
		
			
				
					
					
						
							52 lines
						
					
					
						
							1.2 KiB
						
					
					
				
			
		
		
	
	
							52 lines
						
					
					
						
							1.2 KiB
						
					
					
				'use strict'; | 
						|
const pLimit = require('p-limit'); | 
						|
 | 
						|
class EndError extends Error { | 
						|
	constructor(value) { | 
						|
		super(); | 
						|
		this.value = value; | 
						|
	} | 
						|
} | 
						|
 | 
						|
// The input can also be a promise, so we await it | 
						|
const testElement = async (element, tester) => tester(await element); | 
						|
 | 
						|
// The input can also be a promise, so we `Promise.all()` them both | 
						|
const finder = async element => { | 
						|
	const values = await Promise.all(element); | 
						|
	if (values[1] === true) { | 
						|
		throw new EndError(values[0]); | 
						|
	} | 
						|
 | 
						|
	return false; | 
						|
}; | 
						|
 | 
						|
const pLocate = async (iterable, tester, options) => { | 
						|
	options = { | 
						|
		concurrency: Infinity, | 
						|
		preserveOrder: true, | 
						|
		...options | 
						|
	}; | 
						|
 | 
						|
	const limit = pLimit(options.concurrency); | 
						|
 | 
						|
	// Start all the promises concurrently with optional limit | 
						|
	const items = [...iterable].map(element => [element, limit(testElement, element, tester)]); | 
						|
 | 
						|
	// Check the promises either serially or concurrently | 
						|
	const checkLimit = pLimit(options.preserveOrder ? 1 : Infinity); | 
						|
 | 
						|
	try { | 
						|
		await Promise.all(items.map(element => checkLimit(finder, element))); | 
						|
	} catch (error) { | 
						|
		if (error instanceof EndError) { | 
						|
			return error.value; | 
						|
		} | 
						|
 | 
						|
		throw error; | 
						|
	} | 
						|
}; | 
						|
 | 
						|
module.exports = pLocate; | 
						|
// TODO: Remove this for the next major release | 
						|
module.exports.default = pLocate;
 | 
						|
 |