shelving/util/filter.js

Toolkit for using data in JavaScript.

/** Filter an iterable set of items using a matcher. */
export function* filterItems(items, match, ...args) {
    for (const item of items)
        if (match(item, ...args))
            yield item;
}
/** Filter an array (immutably) using a matcher. */
export function filterArray(input, match, ...args) {
    if (!input.length)
        return input;
    const output = Array.from(filterItems(input, match, ...args));
    return output.length === input.length ? input : output;
}
/** Filter a sequence of values using a matcher. */
export async function* filterSequence(sequence, match, ...args) {
    for await (const item of sequence)
        if (match(item, ...args))
            yield item;
}