@dillonkearns/elm-graphql/examples/src/subscription/node_modules/flow-static-land/lib/Unfoldable.js

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'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.replicate = replicate;
exports.replicateA = replicateA;
exports.none = none;
exports.singleton = singleton;

var _HKT = require('./HKT');

var _Maybe = require('./Maybe');

var maybe = _interopRequireWildcard(_Maybe);

var _Tuple = require('./Tuple');

var _Traversable = require('./Traversable');

var _Fun = require('./Fun');

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

// Replicate a value some natural number of times.


// This class identifies data structures which can be _unfolded_,
// generalizing `unfoldr` on arrays.
function replicate(unfoldable, n, a) {
  function step(n) {
    return n <= 0 ? maybe.Nothing : maybe.of((0, _Tuple.inj)([a, n - 1]));
  }
  return unfoldable.unfoldr(step, n);
}

// Perform an Applicative action `n` times, and accumulate all the results.

function replicateA(applicative, unfoldableTraversable, n, ma) {
  return (0, _Traversable.sequence)(applicative, unfoldableTraversable, replicate(unfoldableTraversable, n, ma));
}

// The container with no elements - unfolded with zero iterations.
function none(unfoldable) {
  return unfoldable.unfoldr((0, _Fun.constant)(maybe.Nothing), undefined);
}

function singleton(unfoldable, a) {
  return replicate(unfoldable, 1, a);
}