aquameta/dist/aquameta.es.js

Node implementation of the Aquameta server

/*
  aquameta
  v0.1.20
  https://github.com/mickburks/node-aquameta
  MIT License
*/

import nodeFetch from 'node-fetch';
import pg from '@micburks/pg';
import url from 'url';
import Router from 'koa-router';
import bodyParser from 'koa-bodyparser';
import Koa from 'koa';
import mount from 'koa-mount';

const fetch = nodeFetch;

/**
 * Fetch query results client-side
 * @returns {Promise}
 */
async function executeEndpoint(client, query) {
  const requestUrl = `/${client.url}/${client.version}/${query.url}`.replace(/\/+/g, '/') // remove duplicate slashes
  .replace(/\/$/, ''); // remove tail slash

  const queryString = getQueryString(query.args);
  const options = {
    method: query.method,
    credentials: 'same-origin',
    headers: {
      'Content-Type': 'application/json'
    }
  };

  if (query.data) {
    options.body = JSON.stringify(query.data);
  }

  try {
    console.log(`endpoint: trying to fetch ${requestUrl}`, options);
    const response = await fetch(queryString ? `${requestUrl}?${queryString}` : requestUrl, options); // Let client deal with status codes

    if (client.rawResponse) {
      return response;
    } else {
      return response.json().then(r => {
        return r.result.map(({
          row
        }) => row);
      });
    }
  } catch (error) {
    // Log error in collapsed group
    console.groupCollapsed(query.method, error.statusCode, error.title);

    if ('message' in error) {
      console.error(error.message);
    }

    console.groupEnd();
    throw error.title;
  }
} // Map the keys of the args object to an array of encoded url components

function getQueryString(args) {
  return Object.keys(args).sort().map(argName => argName in methods && methods[argName](args[argName])).filter(Boolean).join('&').replace(/&&/g, '&');
}

const methods = {
  where(arg) {
    // where: [{ name: 'column_name', op: '=', value: 'value' }]
    return asArray(arg).map(w => `where=${urlEncode(w)}`).join('&');
  },

  order(arg) {
    // order_by: [{ column: 'column_name', direction: 'asc|desc' }]
    // TODO: random()?
    const columnList = asArray(arg).map(col => {
      const {
        column,
        direction = 'asc'
      } = col;
      return direction !== 'asc' ? `-${column}` : `${column}`;
    });
    return `order_by=${encodeURIComponent(columnList.join(','))}`;
  },

  limit(arg) {
    // limit: number
    const parsedNum = parseInt(arg);

    if (!isNaN(parsedNum)) {
      return `limit=${parsedNum}`;
    } else {
      return null;
    }
  },

  offset(arg) {
    // offset: number
    const parsedNum = parseInt(arg);

    if (!isNaN(parsedNum)) {
      return `order=${parsedNum}`;
    } else {
      return null;
    }
  },

  evented() {
    return 'session_id';
  },

  metaData(arg) {
    return `meta_data=${urlEncode(arg)}`;
  },

  args(arg) {
    return `args=${urlEncode(arg)}`;
  },

  exclude(arg) {
    return `exclude=${urlEncode(arg)}`;
  },

  include(arg) {
    return `include=${urlEncode(arg)}`;
  }

};

function urlEncode(str) {
  return encodeURIComponent(JSON.stringify(str));
}

function asArray(arg) {
  return arg instanceof Array ? arg : [arg];
}

const anonConfig = {
  user: 'anonymous',
  database: 'aquameta',
  host: 'localhost',
  port: 5432,
  max: 4,
  idleTimeoutMilliseconds: 30000
};

async function getConnection(config) {
  const mergedConfig = { ...anonConfig,
    ...(config && config.connection || {})
  }; // Don't allow user to be overridden

  mergedConfig.user = anonConfig.user;
  const anonClient = new pg.Client(mergedConfig);
  await anonClient.connect();

  if (!mergedConfig.sessionId) {
    return anonClient;
  }

  let result;

  try {
    result = await anonClient.query('select (role_id).name as role_name from endpoint.session where id = $1::uuid', [mergedConfig.sessionId]);
  } catch (e) {
    await anonClient.end();
    throw e;
  } // If login fails - continue request as anonymous


  if (!result || !result.rows || result.rows.length === 0) {
    return anonClient;
  } // Release Client - TODO: release back to pool


  await anonClient.end(); // Logged in

  const userResult = new Result(result.rows[0]);
  const user = await userResult.json();
  console.log(`connection: logged in as ${user.role_name}`);
  const userClient = new pg.Client({ ...mergedConfig,
    user: user.role_name
  });
  await userClient.connect();
  return userClient;
}
/**
 * Execute query server-side
 * @returns {Promise}
 */


async function executeConnection(client, query) {
  let connection;

  try {
    connection = await getConnection(client); // let result;

    /*
    if (query.args && query.args.source) {
      const {schemaName, relationName, column, name} = parseSourceUrl(
        query.url,
      );
      const queryResult = await connection.query(
        `
        select content, mimetype
        from (select $1 as content, '$1' as extension from $3.$4 where name='$2') as c
        join endpoint.mimetype_extension me on c.extension=me.extension
        join endpoint.mimetype m on me.mimetype_id=m.id;
      `,
        [column, name, schemaName, relationName],
      );
      result = {...queryResult};
      if (result && result.rows && result.rows.length !== 0) {
        result.status = 200;
        result.message = 'OK';
      } else {
        result.status = 404;
        result.status = 'NOT FOUND';
      }
    } else {
      */

    console.log('trying connection', query.version || client.version, query.method, query.url, JSON.stringify(query.args), JSON.stringify(query.data));
    const result = await connection.query('select status, message, response, mimetype ' + 'from endpoint.request($1, $2, $3, $4::json, $5::json)', [query.version || client.version, query.method, query.url, JSON.stringify(query.args), JSON.stringify(query.data)]); //}
    // TODO: end connection if userClient, but release if anonClient?

    await connection.end();
    const res = new Result(result.rows[0]);

    if (client.rawResponse) {
      return res;
    } else {
      return res.json().then(r => {
        if (r.result) {
          return r.result.map(({
            row
          }) => row);
        } else {
          return [];
        }
      });
    }
  } catch (e) {
    // Problem with connecting to database
    console.error(`connection: error trying to connect to database`);
    console.error(e);

    if (connection) {
      await connection.end();
    }

    return null;
  }
}

// Mimic response from fetch
class Result {
  constructor({
    status,
    message,
    response,
    mimetype
  }) {
    this.status = status;
    this.statusText = message;
    this.response = response;
    this.mimetype = mimetype;
  }

  async json() {
    return JSON.parse(this.response);
  }

}
/**
 * TODO I want to keep track of how many pools are open and when they connect
 * pg-pool has some great events
 * pool.on('connect', client => {
 *   client.count = count++
 * })
 */

/**
 * TODO in order to do this, I would have to keep track of the open pools,
 * instead of doing it with pg.connect()
 *
 * var pool = new pg.Pool(config)
 * pool.connect(callback)
 *
 * is the same as
 *
 * pg.connect(config, callback)
 *
 * and this way, pg will keep track of the pools and not create a new one when
 * the same config has been passed in twice
 */


function parseSourceUrl(pathname) {
  const [,, schemaName, relationName, ...rest] = pathname.split('/');
  const fileName = rest.join('/');
  const lastPeriod = fileName.lastIndexOf('.');
  const name = fileName.slice(0, lastPeriod);
  const column = fileName.slice(lastPeriod + 1);
  return {
    schemaName,
    relationName,
    column,
    name
  };
}

/**
 * A function that always returns `true`. Any passed in parameters are ignored.
 *
 * @func
 * @memberOf R
 * @since v0.9.0
 * @category Function
 * @sig * -> Boolean
 * @param {*}
 * @return {Boolean}
 * @see R.F
 * @example
 *
 *      R.T(); //=> true
 */
var T = function () {
  return true;
};

/**
 * A special placeholder value used to specify "gaps" within curried functions,
 * allowing partial application of any combination of arguments, regardless of
 * their positions.
 *
 * If `g` is a curried ternary function and `_` is `R.__`, the following are
 * equivalent:
 *
 *   - `g(1, 2, 3)`
 *   - `g(_, 2, 3)(1)`
 *   - `g(_, _, 3)(1)(2)`
 *   - `g(_, _, 3)(1, 2)`
 *   - `g(_, 2, _)(1, 3)`
 *   - `g(_, 2)(1)(3)`
 *   - `g(_, 2)(1, 3)`
 *   - `g(_, 2)(_, 3)(1)`
 *
 * @name __
 * @constant
 * @memberOf R
 * @since v0.6.0
 * @category Function
 * @example
 *
 *      const greet = R.replace('{name}', R.__, 'Hello, {name}!');
 *      greet('Alice'); //=> 'Hello, Alice!'
 */
var __ = { '@@functional/placeholder': true };

function _isPlaceholder(a) {
       return a != null && typeof a === 'object' && a['@@functional/placeholder'] === true;
}

/**
 * Optimized internal one-arity curry function.
 *
 * @private
 * @category Function
 * @param {Function} fn The function to curry.
 * @return {Function} The curried function.
 */
function _curry1(fn) {
  return function f1(a) {
    if (arguments.length === 0 || _isPlaceholder(a)) {
      return f1;
    } else {
      return fn.apply(this, arguments);
    }
  };
}

/**
 * Optimized internal two-arity curry function.
 *
 * @private
 * @category Function
 * @param {Function} fn The function to curry.
 * @return {Function} The curried function.
 */
function _curry2(fn) {
  return function f2(a, b) {
    switch (arguments.length) {
      case 0:
        return f2;
      case 1:
        return _isPlaceholder(a) ? f2 : _curry1(function (_b) {
          return fn(a, _b);
        });
      default:
        return _isPlaceholder(a) && _isPlaceholder(b) ? f2 : _isPlaceholder(a) ? _curry1(function (_a) {
          return fn(_a, b);
        }) : _isPlaceholder(b) ? _curry1(function (_b) {
          return fn(a, _b);
        }) : fn(a, b);
    }
  };
}

/**
 * Adds two values.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Math
 * @sig Number -> Number -> Number
 * @param {Number} a
 * @param {Number} b
 * @return {Number}
 * @see R.subtract
 * @example
 *
 *      R.add(2, 3);       //=>  5
 *      R.add(7)(10);      //=> 17
 */
var add = /*#__PURE__*/_curry2(function add(a, b) {
  return Number(a) + Number(b);
});

/**
 * Private `concat` function to merge two array-like objects.
 *
 * @private
 * @param {Array|Arguments} [set1=[]] An array-like object.
 * @param {Array|Arguments} [set2=[]] An array-like object.
 * @return {Array} A new, merged array.
 * @example
 *
 *      _concat([4, 5, 6], [1, 2, 3]); //=> [4, 5, 6, 1, 2, 3]
 */
function _concat(set1, set2) {
  set1 = set1 || [];
  set2 = set2 || [];
  var idx;
  var len1 = set1.length;
  var len2 = set2.length;
  var result = [];

  idx = 0;
  while (idx < len1) {
    result[result.length] = set1[idx];
    idx += 1;
  }
  idx = 0;
  while (idx < len2) {
    result[result.length] = set2[idx];
    idx += 1;
  }
  return result;
}

function _arity(n, fn) {
  /* eslint-disable no-unused-vars */
  switch (n) {
    case 0:
      return function () {
        return fn.apply(this, arguments);
      };
    case 1:
      return function (a0) {
        return fn.apply(this, arguments);
      };
    case 2:
      return function (a0, a1) {
        return fn.apply(this, arguments);
      };
    case 3:
      return function (a0, a1, a2) {
        return fn.apply(this, arguments);
      };
    case 4:
      return function (a0, a1, a2, a3) {
        return fn.apply(this, arguments);
      };
    case 5:
      return function (a0, a1, a2, a3, a4) {
        return fn.apply(this, arguments);
      };
    case 6:
      return function (a0, a1, a2, a3, a4, a5) {
        return fn.apply(this, arguments);
      };
    case 7:
      return function (a0, a1, a2, a3, a4, a5, a6) {
        return fn.apply(this, arguments);
      };
    case 8:
      return function (a0, a1, a2, a3, a4, a5, a6, a7) {
        return fn.apply(this, arguments);
      };
    case 9:
      return function (a0, a1, a2, a3, a4, a5, a6, a7, a8) {
        return fn.apply(this, arguments);
      };
    case 10:
      return function (a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) {
        return fn.apply(this, arguments);
      };
    default:
      throw new Error('First argument to _arity must be a non-negative integer no greater than ten');
  }
}

/**
 * Internal curryN function.
 *
 * @private
 * @category Function
 * @param {Number} length The arity of the curried function.
 * @param {Array} received An array of arguments received thus far.
 * @param {Function} fn The function to curry.
 * @return {Function} The curried function.
 */
function _curryN(length, received, fn) {
  return function () {
    var combined = [];
    var argsIdx = 0;
    var left = length;
    var combinedIdx = 0;
    while (combinedIdx < received.length || argsIdx < arguments.length) {
      var result;
      if (combinedIdx < received.length && (!_isPlaceholder(received[combinedIdx]) || argsIdx >= arguments.length)) {
        result = received[combinedIdx];
      } else {
        result = arguments[argsIdx];
        argsIdx += 1;
      }
      combined[combinedIdx] = result;
      if (!_isPlaceholder(result)) {
        left -= 1;
      }
      combinedIdx += 1;
    }
    return left <= 0 ? fn.apply(this, combined) : _arity(left, _curryN(length, combined, fn));
  };
}

/**
 * Returns a curried equivalent of the provided function, with the specified
 * arity. The curried function has two unusual capabilities. First, its
 * arguments needn't be provided one at a time. If `g` is `R.curryN(3, f)`, the
 * following are equivalent:
 *
 *   - `g(1)(2)(3)`
 *   - `g(1)(2, 3)`
 *   - `g(1, 2)(3)`
 *   - `g(1, 2, 3)`
 *
 * Secondly, the special placeholder value [`R.__`](#__) may be used to specify
 * "gaps", allowing partial application of any combination of arguments,
 * regardless of their positions. If `g` is as above and `_` is [`R.__`](#__),
 * the following are equivalent:
 *
 *   - `g(1, 2, 3)`
 *   - `g(_, 2, 3)(1)`
 *   - `g(_, _, 3)(1)(2)`
 *   - `g(_, _, 3)(1, 2)`
 *   - `g(_, 2)(1)(3)`
 *   - `g(_, 2)(1, 3)`
 *   - `g(_, 2)(_, 3)(1)`
 *
 * @func
 * @memberOf R
 * @since v0.5.0
 * @category Function
 * @sig Number -> (* -> a) -> (* -> a)
 * @param {Number} length The arity for the returned function.
 * @param {Function} fn The function to curry.
 * @return {Function} A new, curried function.
 * @see R.curry
 * @example
 *
 *      const sumArgs = (...args) => R.sum(args);
 *
 *      const curriedAddFourNumbers = R.curryN(4, sumArgs);
 *      const f = curriedAddFourNumbers(1, 2);
 *      const g = f(3);
 *      g(4); //=> 10
 */
var curryN = /*#__PURE__*/_curry2(function curryN(length, fn) {
  if (length === 1) {
    return _curry1(fn);
  }
  return _arity(length, _curryN(length, [], fn));
});

/**
 * Optimized internal three-arity curry function.
 *
 * @private
 * @category Function
 * @param {Function} fn The function to curry.
 * @return {Function} The curried function.
 */
function _curry3(fn) {
  return function f3(a, b, c) {
    switch (arguments.length) {
      case 0:
        return f3;
      case 1:
        return _isPlaceholder(a) ? f3 : _curry2(function (_b, _c) {
          return fn(a, _b, _c);
        });
      case 2:
        return _isPlaceholder(a) && _isPlaceholder(b) ? f3 : _isPlaceholder(a) ? _curry2(function (_a, _c) {
          return fn(_a, b, _c);
        }) : _isPlaceholder(b) ? _curry2(function (_b, _c) {
          return fn(a, _b, _c);
        }) : _curry1(function (_c) {
          return fn(a, b, _c);
        });
      default:
        return _isPlaceholder(a) && _isPlaceholder(b) && _isPlaceholder(c) ? f3 : _isPlaceholder(a) && _isPlaceholder(b) ? _curry2(function (_a, _b) {
          return fn(_a, _b, c);
        }) : _isPlaceholder(a) && _isPlaceholder(c) ? _curry2(function (_a, _c) {
          return fn(_a, b, _c);
        }) : _isPlaceholder(b) && _isPlaceholder(c) ? _curry2(function (_b, _c) {
          return fn(a, _b, _c);
        }) : _isPlaceholder(a) ? _curry1(function (_a) {
          return fn(_a, b, c);
        }) : _isPlaceholder(b) ? _curry1(function (_b) {
          return fn(a, _b, c);
        }) : _isPlaceholder(c) ? _curry1(function (_c) {
          return fn(a, b, _c);
        }) : fn(a, b, c);
    }
  };
}

/**
 * Tests whether or not an object is an array.
 *
 * @private
 * @param {*} val The object to test.
 * @return {Boolean} `true` if `val` is an array, `false` otherwise.
 * @example
 *
 *      _isArray([]); //=> true
 *      _isArray(null); //=> false
 *      _isArray({}); //=> false
 */
var _isArray = Array.isArray || function _isArray(val) {
  return val != null && val.length >= 0 && Object.prototype.toString.call(val) === '[object Array]';
};

function _isTransformer(obj) {
  return obj != null && typeof obj['@@transducer/step'] === 'function';
}

/**
 * Returns a function that dispatches with different strategies based on the
 * object in list position (last argument). If it is an array, executes [fn].
 * Otherwise, if it has a function with one of the given method names, it will
 * execute that function (functor case). Otherwise, if it is a transformer,
 * uses transducer [xf] to return a new transformer (transducer case).
 * Otherwise, it will default to executing [fn].
 *
 * @private
 * @param {Array} methodNames properties to check for a custom implementation
 * @param {Function} xf transducer to initialize if object is transformer
 * @param {Function} fn default ramda implementation
 * @return {Function} A function that dispatches on object in list position
 */
function _dispatchable(methodNames, xf, fn) {
  return function () {
    if (arguments.length === 0) {
      return fn();
    }
    var args = Array.prototype.slice.call(arguments, 0);
    var obj = args.pop();
    if (!_isArray(obj)) {
      var idx = 0;
      while (idx < methodNames.length) {
        if (typeof obj[methodNames[idx]] === 'function') {
          return obj[methodNames[idx]].apply(obj, args);
        }
        idx += 1;
      }
      if (_isTransformer(obj)) {
        var transducer = xf.apply(null, args);
        return transducer(obj);
      }
    }
    return fn.apply(this, arguments);
  };
}

var _xfBase = {
  init: function () {
    return this.xf['@@transducer/init']();
  },
  result: function (result) {
    return this.xf['@@transducer/result'](result);
  }
};

/**
 * Returns the larger of its two arguments.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Relation
 * @sig Ord a => a -> a -> a
 * @param {*} a
 * @param {*} b
 * @return {*}
 * @see R.maxBy, R.min
 * @example
 *
 *      R.max(789, 123); //=> 789
 *      R.max('a', 'b'); //=> 'b'
 */
var max = /*#__PURE__*/_curry2(function max(a, b) {
  return b > a ? b : a;
});

function _map(fn, functor) {
  var idx = 0;
  var len = functor.length;
  var result = Array(len);
  while (idx < len) {
    result[idx] = fn(functor[idx]);
    idx += 1;
  }
  return result;
}

function _isString(x) {
  return Object.prototype.toString.call(x) === '[object String]';
}

/**
 * Tests whether or not an object is similar to an array.
 *
 * @private
 * @category Type
 * @category List
 * @sig * -> Boolean
 * @param {*} x The object to test.
 * @return {Boolean} `true` if `x` has a numeric length property and extreme indices defined; `false` otherwise.
 * @example
 *
 *      _isArrayLike([]); //=> true
 *      _isArrayLike(true); //=> false
 *      _isArrayLike({}); //=> false
 *      _isArrayLike({length: 10}); //=> false
 *      _isArrayLike({0: 'zero', 9: 'nine', length: 10}); //=> true
 */
var _isArrayLike = /*#__PURE__*/_curry1(function isArrayLike(x) {
  if (_isArray(x)) {
    return true;
  }
  if (!x) {
    return false;
  }
  if (typeof x !== 'object') {
    return false;
  }
  if (_isString(x)) {
    return false;
  }
  if (x.nodeType === 1) {
    return !!x.length;
  }
  if (x.length === 0) {
    return true;
  }
  if (x.length > 0) {
    return x.hasOwnProperty(0) && x.hasOwnProperty(x.length - 1);
  }
  return false;
});

var XWrap = /*#__PURE__*/function () {
  function XWrap(fn) {
    this.f = fn;
  }
  XWrap.prototype['@@transducer/init'] = function () {
    throw new Error('init not implemented on XWrap');
  };
  XWrap.prototype['@@transducer/result'] = function (acc) {
    return acc;
  };
  XWrap.prototype['@@transducer/step'] = function (acc, x) {
    return this.f(acc, x);
  };

  return XWrap;
}();

function _xwrap(fn) {
  return new XWrap(fn);
}

/**
 * Creates a function that is bound to a context.
 * Note: `R.bind` does not provide the additional argument-binding capabilities of
 * [Function.prototype.bind](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind).
 *
 * @func
 * @memberOf R
 * @since v0.6.0
 * @category Function
 * @category Object
 * @sig (* -> *) -> {*} -> (* -> *)
 * @param {Function} fn The function to bind to context
 * @param {Object} thisObj The context to bind `fn` to
 * @return {Function} A function that will execute in the context of `thisObj`.
 * @see R.partial
 * @example
 *
 *      const log = R.bind(console.log, console);
 *      R.pipe(R.assoc('a', 2), R.tap(log), R.assoc('a', 3))({a: 1}); //=> {a: 3}
 *      // logs {a: 2}
 * @symb R.bind(f, o)(a, b) = f.call(o, a, b)
 */
var bind = /*#__PURE__*/_curry2(function bind(fn, thisObj) {
  return _arity(fn.length, function () {
    return fn.apply(thisObj, arguments);
  });
});

function _arrayReduce(xf, acc, list) {
  var idx = 0;
  var len = list.length;
  while (idx < len) {
    acc = xf['@@transducer/step'](acc, list[idx]);
    if (acc && acc['@@transducer/reduced']) {
      acc = acc['@@transducer/value'];
      break;
    }
    idx += 1;
  }
  return xf['@@transducer/result'](acc);
}

function _iterableReduce(xf, acc, iter) {
  var step = iter.next();
  while (!step.done) {
    acc = xf['@@transducer/step'](acc, step.value);
    if (acc && acc['@@transducer/reduced']) {
      acc = acc['@@transducer/value'];
      break;
    }
    step = iter.next();
  }
  return xf['@@transducer/result'](acc);
}

function _methodReduce(xf, acc, obj, methodName) {
  return xf['@@transducer/result'](obj[methodName](bind(xf['@@transducer/step'], xf), acc));
}

var symIterator = typeof Symbol !== 'undefined' ? Symbol.iterator : '@@iterator';

function _reduce(fn, acc, list) {
  if (typeof fn === 'function') {
    fn = _xwrap(fn);
  }
  if (_isArrayLike(list)) {
    return _arrayReduce(fn, acc, list);
  }
  if (typeof list['fantasy-land/reduce'] === 'function') {
    return _methodReduce(fn, acc, list, 'fantasy-land/reduce');
  }
  if (list[symIterator] != null) {
    return _iterableReduce(fn, acc, list[symIterator]());
  }
  if (typeof list.next === 'function') {
    return _iterableReduce(fn, acc, list);
  }
  if (typeof list.reduce === 'function') {
    return _methodReduce(fn, acc, list, 'reduce');
  }

  throw new TypeError('reduce: list must be array or iterable');
}

var XMap = /*#__PURE__*/function () {
  function XMap(f, xf) {
    this.xf = xf;
    this.f = f;
  }
  XMap.prototype['@@transducer/init'] = _xfBase.init;
  XMap.prototype['@@transducer/result'] = _xfBase.result;
  XMap.prototype['@@transducer/step'] = function (result, input) {
    return this.xf['@@transducer/step'](result, this.f(input));
  };

  return XMap;
}();

var _xmap = /*#__PURE__*/_curry2(function _xmap(f, xf) {
  return new XMap(f, xf);
});

function _has(prop, obj) {
  return Object.prototype.hasOwnProperty.call(obj, prop);
}

var toString = Object.prototype.toString;
var _isArguments = /*#__PURE__*/function () {
  return toString.call(arguments) === '[object Arguments]' ? function _isArguments(x) {
    return toString.call(x) === '[object Arguments]';
  } : function _isArguments(x) {
    return _has('callee', x);
  };
}();

// cover IE < 9 keys issues
var hasEnumBug = ! /*#__PURE__*/{ toString: null }.propertyIsEnumerable('toString');
var nonEnumerableProps = ['constructor', 'valueOf', 'isPrototypeOf', 'toString', 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
// Safari bug
var hasArgsEnumBug = /*#__PURE__*/function () {

  return arguments.propertyIsEnumerable('length');
}();

var contains = function contains(list, item) {
  var idx = 0;
  while (idx < list.length) {
    if (list[idx] === item) {
      return true;
    }
    idx += 1;
  }
  return false;
};

/**
 * Returns a list containing the names of all the enumerable own properties of
 * the supplied object.
 * Note that the order of the output array is not guaranteed to be consistent
 * across different JS platforms.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Object
 * @sig {k: v} -> [k]
 * @param {Object} obj The object to extract properties from
 * @return {Array} An array of the object's own properties.
 * @see R.keysIn, R.values
 * @example
 *
 *      R.keys({a: 1, b: 2, c: 3}); //=> ['a', 'b', 'c']
 */
var keys = typeof Object.keys === 'function' && !hasArgsEnumBug ? /*#__PURE__*/_curry1(function keys(obj) {
  return Object(obj) !== obj ? [] : Object.keys(obj);
}) : /*#__PURE__*/_curry1(function keys(obj) {
  if (Object(obj) !== obj) {
    return [];
  }
  var prop, nIdx;
  var ks = [];
  var checkArgsLength = hasArgsEnumBug && _isArguments(obj);
  for (prop in obj) {
    if (_has(prop, obj) && (!checkArgsLength || prop !== 'length')) {
      ks[ks.length] = prop;
    }
  }
  if (hasEnumBug) {
    nIdx = nonEnumerableProps.length - 1;
    while (nIdx >= 0) {
      prop = nonEnumerableProps[nIdx];
      if (_has(prop, obj) && !contains(ks, prop)) {
        ks[ks.length] = prop;
      }
      nIdx -= 1;
    }
  }
  return ks;
});

/**
 * Takes a function and
 * a [functor](https://github.com/fantasyland/fantasy-land#functor),
 * applies the function to each of the functor's values, and returns
 * a functor of the same shape.
 *
 * Ramda provides suitable `map` implementations for `Array` and `Object`,
 * so this function may be applied to `[1, 2, 3]` or `{x: 1, y: 2, z: 3}`.
 *
 * Dispatches to the `map` method of the second argument, if present.
 *
 * Acts as a transducer if a transformer is given in list position.
 *
 * Also treats functions as functors and will compose them together.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig Functor f => (a -> b) -> f a -> f b
 * @param {Function} fn The function to be called on every element of the input `list`.
 * @param {Array} list The list to be iterated over.
 * @return {Array} The new list.
 * @see R.transduce, R.addIndex
 * @example
 *
 *      const double = x => x * 2;
 *
 *      R.map(double, [1, 2, 3]); //=> [2, 4, 6]
 *
 *      R.map(double, {x: 1, y: 2, z: 3}); //=> {x: 2, y: 4, z: 6}
 * @symb R.map(f, [a, b]) = [f(a), f(b)]
 * @symb R.map(f, { x: a, y: b }) = { x: f(a), y: f(b) }
 * @symb R.map(f, functor_o) = functor_o.map(f)
 */
var map = /*#__PURE__*/_curry2( /*#__PURE__*/_dispatchable(['fantasy-land/map', 'map'], _xmap, function map(fn, functor) {
  switch (Object.prototype.toString.call(functor)) {
    case '[object Function]':
      return curryN(functor.length, function () {
        return fn.call(this, functor.apply(this, arguments));
      });
    case '[object Object]':
      return _reduce(function (acc, key) {
        acc[key] = fn(functor[key]);
        return acc;
      }, {}, keys(functor));
    default:
      return _map(fn, functor);
  }
}));

/**
 * Retrieve the value at a given path.
 *
 * @func
 * @memberOf R
 * @since v0.2.0
 * @category Object
 * @typedefn Idx = String | Int
 * @sig [Idx] -> {a} -> a | Undefined
 * @param {Array} path The path to use.
 * @param {Object} obj The object to retrieve the nested property from.
 * @return {*} The data at `path`.
 * @see R.prop
 * @example
 *
 *      R.path(['a', 'b'], {a: {b: 2}}); //=> 2
 *      R.path(['a', 'b'], {c: {b: 2}}); //=> undefined
 */
var path = /*#__PURE__*/_curry2(function path(paths, obj) {
  var val = obj;
  var idx = 0;
  while (idx < paths.length) {
    if (val == null) {
      return;
    }
    val = val[paths[idx]];
    idx += 1;
  }
  return val;
});

/**
 * Returns a function that when supplied an object returns the indicated
 * property of that object, if it exists.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Object
 * @sig s -> {s: a} -> a | Undefined
 * @param {String} p The property name
 * @param {Object} obj The object to query
 * @return {*} The value at `obj.p`.
 * @see R.path
 * @example
 *
 *      R.prop('x', {x: 100}); //=> 100
 *      R.prop('x', {}); //=> undefined
 *      R.compose(R.inc, R.prop('x'))({ x: 3 }) //=> 4
 */

var prop = /*#__PURE__*/_curry2(function prop(p, obj) {
  return path([p], obj);
});

/**
 * Returns a new list by plucking the same named property off all objects in
 * the list supplied.
 *
 * `pluck` will work on
 * any [functor](https://github.com/fantasyland/fantasy-land#functor) in
 * addition to arrays, as it is equivalent to `R.map(R.prop(k), f)`.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig Functor f => k -> f {k: v} -> f v
 * @param {Number|String} key The key name to pluck off of each object.
 * @param {Array} f The array or functor to consider.
 * @return {Array} The list of values for the given key.
 * @see R.props
 * @example
 *
 *      var getAges = R.pluck('age');
 *      getAges([{name: 'fred', age: 29}, {name: 'wilma', age: 27}]); //=> [29, 27]
 *
 *      R.pluck(0, [[1, 2], [3, 4]]);               //=> [1, 3]
 *      R.pluck('val', {a: {val: 3}, b: {val: 5}}); //=> {a: 3, b: 5}
 * @symb R.pluck('x', [{x: 1, y: 2}, {x: 3, y: 4}, {x: 5, y: 6}]) = [1, 3, 5]
 * @symb R.pluck(0, [[1, 2], [3, 4], [5, 6]]) = [1, 3, 5]
 */
var pluck = /*#__PURE__*/_curry2(function pluck(p, list) {
  return map(prop(p), list);
});

/**
 * Returns a single item by iterating through the list, successively calling
 * the iterator function and passing it an accumulator value and the current
 * value from the array, and then passing the result to the next call.
 *
 * The iterator function receives two values: *(acc, value)*. It may use
 * [`R.reduced`](#reduced) to shortcut the iteration.
 *
 * The arguments' order of [`reduceRight`](#reduceRight)'s iterator function
 * is *(value, acc)*.
 *
 * Note: `R.reduce` does not skip deleted or unassigned indices (sparse
 * arrays), unlike the native `Array.prototype.reduce` method. For more details
 * on this behavior, see:
 * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce#Description
 *
 * Dispatches to the `reduce` method of the third argument, if present. When
 * doing so, it is up to the user to handle the [`R.reduced`](#reduced)
 * shortcuting, as this is not implemented by `reduce`.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig ((a, b) -> a) -> a -> [b] -> a
 * @param {Function} fn The iterator function. Receives two values, the accumulator and the
 *        current element from the array.
 * @param {*} acc The accumulator value.
 * @param {Array} list The list to iterate over.
 * @return {*} The final, accumulated value.
 * @see R.reduced, R.addIndex, R.reduceRight
 * @example
 *
 *      R.reduce(R.subtract, 0, [1, 2, 3, 4]) // => ((((0 - 1) - 2) - 3) - 4) = -10
 *      //          -               -10
 *      //         / \              / \
 *      //        -   4           -6   4
 *      //       / \              / \
 *      //      -   3   ==>     -3   3
 *      //     / \              / \
 *      //    -   2           -1   2
 *      //   / \              / \
 *      //  0   1            0   1
 *
 * @symb R.reduce(f, a, [b, c, d]) = f(f(f(a, b), c), d)
 */
var reduce = /*#__PURE__*/_curry3(_reduce);

/**
 * Returns a function that always returns the given value. Note that for
 * non-primitives the value returned is a reference to the original value.
 *
 * This function is known as `const`, `constant`, or `K` (for K combinator) in
 * other languages and libraries.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Function
 * @sig a -> (* -> a)
 * @param {*} val The value to wrap in a function
 * @return {Function} A Function :: * -> val.
 * @example
 *
 *      const t = R.always('Tee');
 *      t(); //=> 'Tee'
 */
var always = /*#__PURE__*/_curry1(function always(val) {
  return function () {
    return val;
  };
});

/**
 * ap applies a list of functions to a list of values.
 *
 * Dispatches to the `ap` method of the second argument, if present. Also
 * treats curried functions as applicatives.
 *
 * @func
 * @memberOf R
 * @since v0.3.0
 * @category Function
 * @sig [a -> b] -> [a] -> [b]
 * @sig Apply f => f (a -> b) -> f a -> f b
 * @sig (r -> a -> b) -> (r -> a) -> (r -> b)
 * @param {*} applyF
 * @param {*} applyX
 * @return {*}
 * @example
 *
 *      R.ap([R.multiply(2), R.add(3)], [1,2,3]); //=> [2, 4, 6, 4, 5, 6]
 *      R.ap([R.concat('tasty '), R.toUpper], ['pizza', 'salad']); //=> ["tasty pizza", "tasty salad", "PIZZA", "SALAD"]
 *
 *      // R.ap can also be used as S combinator
 *      // when only two functions are passed
 *      R.ap(R.concat, R.toUpper)('Ramda') //=> 'RamdaRAMDA'
 * @symb R.ap([f, g], [a, b]) = [f(a), f(b), g(a), g(b)]
 */
var ap = /*#__PURE__*/_curry2(function ap(applyF, applyX) {
  return typeof applyX['fantasy-land/ap'] === 'function' ? applyX['fantasy-land/ap'](applyF) : typeof applyF.ap === 'function' ? applyF.ap(applyX) : typeof applyF === 'function' ? function (x) {
    return applyF(x)(applyX(x));
  } : _reduce(function (acc, f) {
    return _concat(acc, map(f, applyX));
  }, [], applyF);
});

/**
 * Determine if the passed argument is an integer.
 *
 * @private
 * @param {*} n
 * @category Type
 * @return {Boolean}
 */

function _isFunction(x) {
  return Object.prototype.toString.call(x) === '[object Function]';
}

/**
 * "lifts" a function to be the specified arity, so that it may "map over" that
 * many lists, Functions or other objects that satisfy the [FantasyLand Apply spec](https://github.com/fantasyland/fantasy-land#apply).
 *
 * @func
 * @memberOf R
 * @since v0.7.0
 * @category Function
 * @sig Number -> (*... -> *) -> ([*]... -> [*])
 * @param {Function} fn The function to lift into higher context
 * @return {Function} The lifted function.
 * @see R.lift, R.ap
 * @example
 *
 *      const madd3 = R.liftN(3, (...args) => R.sum(args));
 *      madd3([1,2,3], [1,2,3], [1]); //=> [3, 4, 5, 4, 5, 6, 5, 6, 7]
 */
var liftN = /*#__PURE__*/_curry2(function liftN(arity, fn) {
  var lifted = curryN(arity, fn);
  return curryN(arity, function () {
    return _reduce(ap, map(lifted, arguments[0]), Array.prototype.slice.call(arguments, 1));
  });
});

/**
 * "lifts" a function of arity > 1 so that it may "map over" a list, Function or other
 * object that satisfies the [FantasyLand Apply spec](https://github.com/fantasyland/fantasy-land#apply).
 *
 * @func
 * @memberOf R
 * @since v0.7.0
 * @category Function
 * @sig (*... -> *) -> ([*]... -> [*])
 * @param {Function} fn The function to lift into higher context
 * @return {Function} The lifted function.
 * @see R.liftN
 * @example
 *
 *      const madd3 = R.lift((a, b, c) => a + b + c);
 *
 *      madd3([1,2,3], [1,2,3], [1]); //=> [3, 4, 5, 4, 5, 6, 5, 6, 7]
 *
 *      const madd5 = R.lift((a, b, c, d, e) => a + b + c + d + e);
 *
 *      madd5([1,2], [3], [4, 5], [6], [7, 8]); //=> [21, 22, 22, 23, 22, 23, 23, 24]
 */
var lift = /*#__PURE__*/_curry1(function lift(fn) {
  return liftN(fn.length, fn);
});

/**
 * Returns a curried equivalent of the provided function. The curried function
 * has two unusual capabilities. First, its arguments needn't be provided one
 * at a time. If `f` is a ternary function and `g` is `R.curry(f)`, the
 * following are equivalent:
 *
 *   - `g(1)(2)(3)`
 *   - `g(1)(2, 3)`
 *   - `g(1, 2)(3)`
 *   - `g(1, 2, 3)`
 *
 * Secondly, the special placeholder value [`R.__`](#__) may be used to specify
 * "gaps", allowing partial application of any combination of arguments,
 * regardless of their positions. If `g` is as above and `_` is [`R.__`](#__),
 * the following are equivalent:
 *
 *   - `g(1, 2, 3)`
 *   - `g(_, 2, 3)(1)`
 *   - `g(_, _, 3)(1)(2)`
 *   - `g(_, _, 3)(1, 2)`
 *   - `g(_, 2)(1)(3)`
 *   - `g(_, 2)(1, 3)`
 *   - `g(_, 2)(_, 3)(1)`
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Function
 * @sig (* -> a) -> (* -> a)
 * @param {Function} fn The function to curry.
 * @return {Function} A new, curried function.
 * @see R.curryN, R.partial
 * @example
 *
 *      const addFourNumbers = (a, b, c, d) => a + b + c + d;
 *
 *      const curriedAddFourNumbers = R.curry(addFourNumbers);
 *      const f = curriedAddFourNumbers(1, 2);
 *      const g = f(3);
 *      g(4); //=> 10
 */
var curry = /*#__PURE__*/_curry1(function curry(fn) {
  return curryN(fn.length, fn);
});

/**
 * Returns the result of calling its first argument with the remaining
 * arguments. This is occasionally useful as a converging function for
 * [`R.converge`](#converge): the first branch can produce a function while the
 * remaining branches produce values to be passed to that function as its
 * arguments.
 *
 * @func
 * @memberOf R
 * @since v0.9.0
 * @category Function
 * @sig (*... -> a),*... -> a
 * @param {Function} fn The function to apply to the remaining arguments.
 * @param {...*} args Any number of positional arguments.
 * @return {*}
 * @see R.apply
 * @example
 *
 *      R.call(R.add, 1, 2); //=> 3
 *
 *      const indentN = R.pipe(R.repeat(' '),
 *                           R.join(''),
 *                           R.replace(/^(?!$)/gm));
 *
 *      const format = R.converge(R.call, [
 *                                  R.pipe(R.prop('indent'), indentN),
 *                                  R.prop('value')
 *                              ]);
 *
 *      format({indent: 2, value: 'foo\nbar\nbaz\n'}); //=> '  foo\n  bar\n  baz\n'
 * @symb R.call(f, a, b) = f(a, b)
 */
var call = /*#__PURE__*/curry(function call(fn) {
  return fn.apply(this, Array.prototype.slice.call(arguments, 1));
});

/**
 * `_makeFlat` is a helper function that returns a one-level or fully recursive
 * function based on the flag passed in.
 *
 * @private
 */
function _makeFlat(recursive) {
  return function flatt(list) {
    var value, jlen, j;
    var result = [];
    var idx = 0;
    var ilen = list.length;

    while (idx < ilen) {
      if (_isArrayLike(list[idx])) {
        value = recursive ? flatt(list[idx]) : list[idx];
        j = 0;
        jlen = value.length;
        while (j < jlen) {
          result[result.length] = value[j];
          j += 1;
        }
      } else {
        result[result.length] = list[idx];
      }
      idx += 1;
    }
    return result;
  };
}

function _forceReduced(x) {
  return {
    '@@transducer/value': x,
    '@@transducer/reduced': true
  };
}

var preservingReduced = function (xf) {
  return {
    '@@transducer/init': _xfBase.init,
    '@@transducer/result': function (result) {
      return xf['@@transducer/result'](result);
    },
    '@@transducer/step': function (result, input) {
      var ret = xf['@@transducer/step'](result, input);
      return ret['@@transducer/reduced'] ? _forceReduced(ret) : ret;
    }
  };
};

var _flatCat = function _xcat(xf) {
  var rxf = preservingReduced(xf);
  return {
    '@@transducer/init': _xfBase.init,
    '@@transducer/result': function (result) {
      return rxf['@@transducer/result'](result);
    },
    '@@transducer/step': function (result, input) {
      return !_isArrayLike(input) ? _reduce(rxf, result, [input]) : _reduce(rxf, result, input);
    }
  };
};

var _xchain = /*#__PURE__*/_curry2(function _xchain(f, xf) {
  return map(f, _flatCat(xf));
});

/**
 * `chain` maps a function over a list and concatenates the results. `chain`
 * is also known as `flatMap` in some libraries.
 *
 * Dispatches to the `chain` method of the second argument, if present,
 * according to the [FantasyLand Chain spec](https://github.com/fantasyland/fantasy-land#chain).
 *
 * If second argument is a function, `chain(f, g)(x)` is equivalent to `f(g(x), x)`.
 *
 * Acts as a transducer if a transformer is given in list position.
 *
 * @func
 * @memberOf R
 * @since v0.3.0
 * @category List
 * @sig Chain m => (a -> m b) -> m a -> m b
 * @param {Function} fn The function to map with
 * @param {Array} list The list to map over
 * @return {Array} The result of flat-mapping `list` with `fn`
 * @example
 *
 *      const duplicate = n => [n, n];
 *      R.chain(duplicate, [1, 2, 3]); //=> [1, 1, 2, 2, 3, 3]
 *
 *      R.chain(R.append, R.head)([1, 2, 3]); //=> [1, 2, 3, 1]
 */
var chain = /*#__PURE__*/_curry2( /*#__PURE__*/_dispatchable(['fantasy-land/chain', 'chain'], _xchain, function chain(fn, monad) {
  if (typeof monad === 'function') {
    return function (x) {
      return fn(monad(x))(x);
    };
  }
  return _makeFlat(false)(map(fn, monad));
}));

/**
 * Gives a single-word string description of the (native) type of a value,
 * returning such answers as 'Object', 'Number', 'Array', or 'Null'. Does not
 * attempt to distinguish user Object types any further, reporting them all as
 * 'Object'.
 *
 * @func
 * @memberOf R
 * @since v0.8.0
 * @category Type
 * @sig (* -> {*}) -> String
 * @param {*} val The value to test
 * @return {String}
 * @example
 *
 *      R.type({}); //=> "Object"
 *      R.type(1); //=> "Number"
 *      R.type(false); //=> "Boolean"
 *      R.type('s'); //=> "String"
 *      R.type(null); //=> "Null"
 *      R.type([]); //=> "Array"
 *      R.type(/[A-z]/); //=> "RegExp"
 *      R.type(() => {}); //=> "Function"
 *      R.type(undefined); //=> "Undefined"
 */
var type = /*#__PURE__*/_curry1(function type(val) {
  return val === null ? 'Null' : val === undefined ? 'Undefined' : Object.prototype.toString.call(val).slice(8, -1);
});

/**
 * A function that returns the `!` of its argument. It will return `true` when
 * passed false-y value, and `false` when passed a truth-y one.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Logic
 * @sig * -> Boolean
 * @param {*} a any value
 * @return {Boolean} the logical inverse of passed argument.
 * @see R.complement
 * @example
 *
 *      R.not(true); //=> false
 *      R.not(false); //=> true
 *      R.not(0); //=> true
 *      R.not(1); //=> false
 */
var not = /*#__PURE__*/_curry1(function not(a) {
  return !a;
});

/**
 * Takes a function `f` and returns a function `g` such that if called with the same arguments
 * when `f` returns a "truthy" value, `g` returns `false` and when `f` returns a "falsy" value `g` returns `true`.
 *
 * `R.complement` may be applied to any functor
 *
 * @func
 * @memberOf R
 * @since v0.12.0
 * @category Logic
 * @sig (*... -> *) -> (*... -> Boolean)
 * @param {Function} f
 * @return {Function}
 * @see R.not
 * @example
 *
 *      const isNotNil = R.complement(R.isNil);
 *      isNil(null); //=> true
 *      isNotNil(null); //=> false
 *      isNil(7); //=> false
 *      isNotNil(7); //=> true
 */
var complement = /*#__PURE__*/lift(not);

function _pipe(f, g) {
  return function () {
    return g.call(this, f.apply(this, arguments));
  };
}

/**
 * This checks whether a function has a [methodname] function. If it isn't an
 * array it will execute that function otherwise it will default to the ramda
 * implementation.
 *
 * @private
 * @param {Function} fn ramda implemtation
 * @param {String} methodname property to check for a custom implementation
 * @return {Object} Whatever the return value of the method is.
 */
function _checkForMethod(methodname, fn) {
  return function () {
    var length = arguments.length;
    if (length === 0) {
      return fn();
    }
    var obj = arguments[length - 1];
    return _isArray(obj) || typeof obj[methodname] !== 'function' ? fn.apply(this, arguments) : obj[methodname].apply(obj, Array.prototype.slice.call(arguments, 0, length - 1));
  };
}

/**
 * Returns the elements of the given list or string (or object with a `slice`
 * method) from `fromIndex` (inclusive) to `toIndex` (exclusive).
 *
 * Dispatches to the `slice` method of the third argument, if present.
 *
 * @func
 * @memberOf R
 * @since v0.1.4
 * @category List
 * @sig Number -> Number -> [a] -> [a]
 * @sig Number -> Number -> String -> String
 * @param {Number} fromIndex The start index (inclusive).
 * @param {Number} toIndex The end index (exclusive).
 * @param {*} list
 * @return {*}
 * @example
 *
 *      R.slice(1, 3, ['a', 'b', 'c', 'd']);        //=> ['b', 'c']
 *      R.slice(1, Infinity, ['a', 'b', 'c', 'd']); //=> ['b', 'c', 'd']
 *      R.slice(0, -1, ['a', 'b', 'c', 'd']);       //=> ['a', 'b', 'c']
 *      R.slice(-3, -1, ['a', 'b', 'c', 'd']);      //=> ['b', 'c']
 *      R.slice(0, 3, 'ramda');                     //=> 'ram'
 */
var slice = /*#__PURE__*/_curry3( /*#__PURE__*/_checkForMethod('slice', function slice(fromIndex, toIndex, list) {
  return Array.prototype.slice.call(list, fromIndex, toIndex);
}));

/**
 * Returns all but the first element of the given list or string (or object
 * with a `tail` method).
 *
 * Dispatches to the `slice` method of the first argument, if present.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig [a] -> [a]
 * @sig String -> String
 * @param {*} list
 * @return {*}
 * @see R.head, R.init, R.last
 * @example
 *
 *      R.tail([1, 2, 3]);  //=> [2, 3]
 *      R.tail([1, 2]);     //=> [2]
 *      R.tail([1]);        //=> []
 *      R.tail([]);         //=> []
 *
 *      R.tail('abc');  //=> 'bc'
 *      R.tail('ab');   //=> 'b'
 *      R.tail('a');    //=> ''
 *      R.tail('');     //=> ''
 */
var tail = /*#__PURE__*/_curry1( /*#__PURE__*/_checkForMethod('tail', /*#__PURE__*/slice(1, Infinity)));

/**
 * Performs left-to-right function composition. The leftmost function may have
 * any arity; the remaining functions must be unary.
 *
 * In some libraries this function is named `sequence`.
 *
 * **Note:** The result of pipe is not automatically curried.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Function
 * @sig (((a, b, ..., n) -> o), (o -> p), ..., (x -> y), (y -> z)) -> ((a, b, ..., n) -> z)
 * @param {...Function} functions
 * @return {Function}
 * @see R.compose
 * @example
 *
 *      const f = R.pipe(Math.pow, R.negate, R.inc);
 *
 *      f(3, 4); // -(3^4) + 1
 * @symb R.pipe(f, g, h)(a, b) = h(g(f(a, b)))
 */
function pipe() {
  if (arguments.length === 0) {
    throw new Error('pipe requires at least one argument');
  }
  return _arity(arguments[0].length, reduce(_pipe, arguments[0], tail(arguments)));
}

/**
 * Returns a new list or string with the elements or characters in reverse
 * order.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig [a] -> [a]
 * @sig String -> String
 * @param {Array|String} list
 * @return {Array|String}
 * @example
 *
 *      R.reverse([1, 2, 3]);  //=> [3, 2, 1]
 *      R.reverse([1, 2]);     //=> [2, 1]
 *      R.reverse([1]);        //=> [1]
 *      R.reverse([]);         //=> []
 *
 *      R.reverse('abc');      //=> 'cba'
 *      R.reverse('ab');       //=> 'ba'
 *      R.reverse('a');        //=> 'a'
 *      R.reverse('');         //=> ''
 */
var reverse = /*#__PURE__*/_curry1(function reverse(list) {
  return _isString(list) ? list.split('').reverse().join('') : Array.prototype.slice.call(list, 0).reverse();
});

/**
 * Performs right-to-left function composition. The rightmost function may have
 * any arity; the remaining functions must be unary.
 *
 * **Note:** The result of compose is not automatically curried.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Function
 * @sig ((y -> z), (x -> y), ..., (o -> p), ((a, b, ..., n) -> o)) -> ((a, b, ..., n) -> z)
 * @param {...Function} ...functions The functions to compose
 * @return {Function}
 * @see R.pipe
 * @example
 *
 *      const classyGreeting = (firstName, lastName) => "The name's " + lastName + ", " + firstName + " " + lastName
 *      const yellGreeting = R.compose(R.toUpper, classyGreeting);
 *      yellGreeting('James', 'Bond'); //=> "THE NAME'S BOND, JAMES BOND"
 *
 *      R.compose(Math.abs, R.add(1), R.multiply(2))(-4) //=> 7
 *
 * @symb R.compose(f, g, h)(a, b) = f(g(h(a, b)))
 */
function compose() {
  if (arguments.length === 0) {
    throw new Error('compose requires at least one argument');
  }
  return pipe.apply(this, reverse(arguments));
}

/**
 * Returns the nth element of the given list or string. If n is negative the
 * element at index length + n is returned.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig Number -> [a] -> a | Undefined
 * @sig Number -> String -> String
 * @param {Number} offset
 * @param {*} list
 * @return {*}
 * @example
 *
 *      const list = ['foo', 'bar', 'baz', 'quux'];
 *      R.nth(1, list); //=> 'bar'
 *      R.nth(-1, list); //=> 'quux'
 *      R.nth(-99, list); //=> undefined
 *
 *      R.nth(2, 'abc'); //=> 'c'
 *      R.nth(3, 'abc'); //=> ''
 * @symb R.nth(-1, [a, b, c]) = c
 * @symb R.nth(0, [a, b, c]) = a
 * @symb R.nth(1, [a, b, c]) = b
 */
var nth = /*#__PURE__*/_curry2(function nth(offset, list) {
  var idx = offset < 0 ? list.length + offset : offset;
  return _isString(list) ? list.charAt(idx) : list[idx];
});

/**
 * Returns the first element of the given list or string. In some libraries
 * this function is named `first`.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig [a] -> a | Undefined
 * @sig String -> String
 * @param {Array|String} list
 * @return {*}
 * @see R.tail, R.init, R.last
 * @example
 *
 *      R.head(['fi', 'fo', 'fum']); //=> 'fi'
 *      R.head([]); //=> undefined
 *
 *      R.head('abc'); //=> 'a'
 *      R.head(''); //=> ''
 */
var head = /*#__PURE__*/nth(0);

function _identity(x) {
  return x;
}

/**
 * A function that does nothing but return the parameter supplied to it. Good
 * as a default or placeholder function.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category Function
 * @sig a -> a
 * @param {*} x The value to return.
 * @return {*} The input value, `x`.
 * @example