iter-tools-es/impls/$flat/async-flat.js

The iterable toolbox

const {
  asyncIterableCurry,
  asyncIsLoopable
} = require('../../internal/async-iterable.js');

const {
  validateArgs
} = require('./internal/validate-args.js');

const defaultShouldFlat = value => typeof value !== 'string' && asyncIsLoopable(value);

async function* asyncFlatInternal(shouldFlat, depth, currentDepth, source) {
  for await (const value of source) {
    if (currentDepth < depth && (await shouldFlat(value))) {
      yield* asyncFlatInternal(shouldFlat, depth, currentDepth + 1, value);
    } else {
      yield value;
    }
  }
}

function __asyncFlat(source, depth = 1, shouldFlat = defaultShouldFlat) {
  return asyncFlatInternal(shouldFlat, depth, 0, source);
}

exports.__asyncFlat = __asyncFlat;
const asyncFlat = /*#__PURE__*/asyncIterableCurry(__asyncFlat, {
  minArgs: 0,
  maxArgs: 2,
  validateArgs
});
exports.asyncFlat = asyncFlat;