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

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'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.asks = undefined;
exports.inj = inj;
exports.prj = prj;
exports.runReader = runReader;
exports.ask = ask;
exports.local = local;
exports.map = map;
exports.ap = ap;
exports.of = of;
exports.chain = chain;

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

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

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

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

var IsReader = function IsReader() {
  _classCallCheck(this, IsReader);
};

function inj(a) {
  return a;
}

function prj(fa) {
  return fa;
}

function runReader(r, e) {
  return prj(r)(e);
}

// reads the current context
function ask() {
  return inj(_Identity.id);
}

var asks = exports.asks = inj;

// changes the value of the local context during the execution of the action `fa`
function local(f, fa) {
  return inj(function (e) {
    return runReader(fa, f(e));
  });
}

function map(f, fa) {
  return inj((0, _Fun.compose)(f, prj(fa)));
}

function ap(fab, fa) {
  return chain(function (f) {
    return map(f, fa);
  }, fab); // <= derived
}

function of(a) {
  return inj(function () {
    return a;
  });
}

function chain(f, fa) {
  return inj(function (e) {
    return prj(f(runReader(fa, e)))(e);
  });
}

if (false) {
  // eslint-disable-line
  ({
    map: map,
    ap: ap,
    of: of,
    chain: chain
  });
}