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

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'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.modify = undefined;
exports.asFold = asFold;
exports.asSetter = asSetter;
exports.composeTraversal = composeTraversal;
exports.fromTraversable = fromTraversable;

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

var _Const = require('./Const');

var _Identity = require('./Identity');

var id = _interopRequireWildcard(_Identity);

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; } }

function _modify(traversal, f, s) {
  return id.extract(traversal.modifyF(id, function (a) {
    return id.of(f(a));
  }, s));
}

/*

  A Traversal is the generalisation of an Optional to several targets.
  In other word, a Traversal allows to focus from a type S into 0 to n values of type A.

  The most common example of a Traversal would be to focus into all elements inside of a container (e.g. List, Maybe).

*/

exports.modify = _modify;
function asFold(traversal) {
  return {
    foldMap: function foldMap(monoid, f, s) {
      return (0, _Const.prj)(traversal.modifyF((0, _Const.getApplicative)(monoid), function (a) {
        return (0, _Const.inj)(f(a));
      }, s));
    }
  };
}

function asSetter(traversal) {
  return {
    modify: function modify(f, s) {
      return _modify(traversal, f, s);
    }
  };
}

function composeTraversal(ab, st) {
  return {
    modifyF: function modifyF(applicative, f, s) {
      return st.modifyF(applicative, function (c) {
        return ab.modifyF(applicative, f, c);
      }, s);
    }
  };
}

function fromTraversable(traversable) {
  return {
    modifyF: function modifyF(applicative, f, s) {
      return traversable.traverse(applicative, f, s);
    }
  };
}