hifo – highest in, first out ⚖

Remembers the highest/lowest values in a data set of any size. Useful if you have a large number of values, but are only interested in the n highest (or lowest) ones. If you looking for a stream version, check out hifo-stream.

• hifo is fast. To find the highest m of n values, the time complexity is O(m * n).
• It is memory-efficient. If you specifiy its size as 50, it will only store 50 values in memory.
• hifo works with numeric values and simple objects out of the box, but you can pass your own sort function.

Example

Let's assume we have a huge array of people.

var people = [
	{ name: 'Alice', age: 23 },
	{ name: 'Eve', age: 45 },
	{ name: 'Jane', age: 19 },
	{ name: 'Bob', age: 30 },
	{ name: 'John', age: 60 },
	// thousands of others
];

To find the 3 oldest people, we reate a new Hifo instance and pass the 'age' as the filter key and 3 as the size.

var hifo = require('hifo');

var oldest = hifo(hifo.highest('age'), 3);
for (var person in people) {
	oldest.add(person);
}

oldest.data will now look like this:

[
	{ name: 'John', age: 60 },
	{ name: 'Eve', age: 45 },
	{ name: 'Bob', age: 30 }
]

Of course you can do this kind of filtering with hifo.lowest as well.

Contributing

If you have a question, found a bug or want to propose a feature, have a look at the issues page.