bridge-scorer/dist/bridge-scorer.spec.js

collection of duplicate bridge scoring algorithms.

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.spec = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
'use strict';

var scorer = module.exports = {};

scorer.contractMade = require('./lib/contract').made;
scorer.contractTricks = require('./lib/contract').tricks;
scorer.contractResult = require('./lib/contract').result;
scorer.matchpoints = require('./lib/matchpoints').standard;
scorer.matchpointsACBL = require('./lib/matchpoints').ACBL;
scorer.crossImps = require('./lib/imps').crossImps;
scorer.butler = require('./lib/imps').butler;
scorer.rank = require('./lib/rank');

},{"./lib/contract":2,"./lib/imps":3,"./lib/matchpoints":4,"./lib/rank":5}],2:[function(require,module,exports){
'use strict';

var doubledNotVulnerable = [
     0,      -100,   -300,   -500,
     -800,  -1100,  -1400,  -1700,
     -2000, -2300,  -2600,  -2900,
     -3200, -3500
];

var doubledVulnerable = [
     0,      -200,  -500,  -800,
     -1100, -1400, -1700, -2000,
     -2300, -2600, -2900, -3200,
     -3500, -3800
];

/**
 * Scores a bridge contract.
 */
function contractMade(contract, vulnerable, made) {
    // Passed in?
    if (contract.level === 0)
        return 0;
    
    var 
        overTricks = made - contract.level,
        doubled = contract.risk === 'X',
        redoubled = contract.risk === 'XX',
        strain = contract.denomination;

    // Undertricks?
    if (made < 0) {
        if (contract.risk === '')
            return made * (vulnerable ? 100 : 50);
        var penalty = vulnerable ? doubledVulnerable[-made] : doubledNotVulnerable[-made];
        if (redoubled)
            penalty *= 2;
        return penalty;
    }

    var score = 0;

    // Contract Points
    switch (strain) {
        case 'S':
        case 'H':
            score = contract.level * 30;
            break;
        case 'NT':
            score = contract.level * 30 + 10;
            break;
        case 'C':
        case 'D':
            score = contract.level * 20;
            break;
    }
    if (doubled)
        score *= 2;
    else if (redoubled)
        score *= 4;

    // Level Bonus
    if (score < 100) // Part score?
        score += 50;
    else {
        score += vulnerable ? 500 : 300; // game bonus
        if (contract.level === 7) // Grand slam?
            score += vulnerable ? 1500 : 1000;
        else if (contract.level === 6) // small slam?
            score += vulnerable ? 750 : 500;
    }

    // Insult bonus
    if (doubled)
        score += 50;
    else if (redoubled)
        score += 100;

    // Overtrick bonus
    if (overTricks > 0) {
        if (doubled)
            score += overTricks * (vulnerable ? 200 : 100);
        else if (redoubled)
            score += overTricks * (vulnerable ? 400 : 200);
        else {
            switch (strain) {
                case 'S':
                case 'H':
                case 'NT':
                    score += overTricks * 30;
                    break;
                case 'C':
                case 'D':
                    score += overTricks * 20;
                    break;
            }
        }
    }

    return score;
}

function contractTricks(contract, vulnerable, tricks) {
    var need = contract.level + 6;
    var made = tricks < need ? tricks - need : tricks - 6;
    return contractMade(
        contract,
        vulnerable,
        made
    );
}

function contractResult(contract, vulnerable, relativeTricks) {
    return contractTricks(
        contract,
        vulnerable,
        relativeTricks + contract.level + 6
    );
}

module.exports = {
    made: contractMade,
    tricks: contractTricks,
    result: contractResult
};

},{}],3:[function(require,module,exports){
'use strict';

var imps = [
    { diff: 0, imps: 0},
    { diff: 20, imps: 1},
    { diff: 50, imps: 2},
    { diff: 90, imps: 3},
    { diff: 130, imps: 4},
    { diff: 170, imps: 5},
    { diff: 220, imps: 6},
    { diff: 270, imps: 7},
    { diff: 320, imps: 8},
    { diff: 370, imps: 9},
    { diff: 430, imps: 10},
    { diff: 500, imps: 11},
    { diff: 600, imps: 12},
    { diff: 750, imps: 13},
    { diff: 900, imps: 14},
    { diff: 1100, imps: 15},
    { diff: 1300, imps: 16},
    { diff: 1500, imps: 17},
    { diff: 1750, imps: 18},
    { diff: 2000, imps: 19},
    { diff: 2250, imps: 20},
    { diff: 2500, imps: 21},
    { diff: 3000, imps: 22},
    { diff: 3500, imps: 23},
    { diff: 4000, imps: 24},
];

function toImps(diff) {
    var n = imps.length - 1;
    var sign = 1;
    if (diff < 0) {
        sign = -1;
        diff = 0 - diff;
    }
    for (var i = 0; i < n; ++i) {
        if (imps[i].diff <= diff && diff < imps[i+1].diff) {
            return imps[i].imps * sign;
        }
    }
    return 24 * sign;
}

function crossImps(games) {
    var i, j, game, score, imps;

    // Get the played games
    var played = [];
    for (i = 0; i < games.length; ++i) {
        game = games[i];
        if (game.score === 0) {
            game.impsNS = { value: -1};
            game.impsEW = { value: -1};
            played.push({
                game: game,
                scoreNS: 0
            });
        }
        else if (game.contract && game.contract.declaror && game.score) {
            game.impsNS = { value: -1};
            game.impsEW = { value: -1};
            var playedGame = {
                game: game,
                scoreNS: (game.contract.declaror === 'N' || game.contract.declaror === 'S') ? game.score : -game.score
            };
            played.push(playedGame);
        }
    }

    // Assign imps
    for (i = 0; i < played.length; ++i) {
        score = played[i].scoreNS;
        imps = 0;
        for (j = 0; j < played.length; ++j) {
            if (i !== j){
                imps += toImps(score - played[j].scoreNS);
            }
        }
        played[i].game.impsNS.value = imps / (played.length - 1);
        played[i].game.impsEW.value = -played[i].game.impsNS.value;
    }
}

function pairsDatum(games, f) {
    var i, game, score, imps;

    // Get the played games
    var played = [];
    for (i = 0; i < games.length; ++i) {
        game = games[i];
        if (game.score === 0) {
            game.impsNS = { value: -1};
            game.impsEW = { value: -1};
            played.push({
                game: game,
                scoreNS: 0
            });
        }
        else if (game.contract && game.contract.declaror && game.score) {
            game.impsNS = { value: -1};
            game.impsEW = { value: -1};
            var playedGame = {
                game: game,
                scoreNS: (game.contract.declaror === 'N' || game.contract.declaror === 'S') ? game.score : -game.score
            };
            played.push(playedGame);
        }
    }

    // Determine the datum
    var datum = f(played);

    // Assign imps
    for (i = 0; i < played.length; ++i) {
        score = played[i].scoreNS;
        imps = toImps(score - datum);
        played[i].game.impsNS.value = imps;
        played[i].game.impsEW.value = -imps;
    }

    return datum;
}

function butler (games) {
    var datum = function(g) {
        if (g.length > 3) {
            g.sort(function (a,b) { return b.scoreNS - a.scoreNS; });
            var drops = Math.ceil((g.length - 10) / 15) + 1;
            g = g.slice(drops, -drops);
        }
        var sum = g.reduce(function (a, e) { return a + e.scoreNS; }, 0);
        return Math.round((sum / g.length) / 10) * 10;
    };

    return pairsDatum(games, datum);
}

module.exports = {
    toImps: toImps,
    crossImps: crossImps,
    butler: butler
};

},{}],4:[function(require,module,exports){
'use strict';

function matchpoints (games, scoring) {
    var i, game;
    
    // Get the played games
    var played = [];
    for (i = 0; i < games.length; ++i) {
        game = games[i];
        if (game.score === 0) {
            game.matchpointsNS = { value: -1};
            game.matchpointsEW = { value: -1};
            played.push({
                game: game,
                scoreNS: 0
            });
        }
        else if (game.contract && game.contract.declaror && game.score) {
            game.matchpointsNS = { value: -1};
            game.matchpointsEW = { value: -1};
            var playedGame = { 
                game: game,
                scoreNS: (game.contract.declaror === 'N' || game.contract.declaror === 'S') ? game.score : -game.score
            };
            played.push(playedGame);
        }
    }
    
    var totalMatchpoints = played.length * scoring.win - scoring.win;
    
    // Order the played games by descending NS score (highest score first)
    played.sort(function (a,b) { return b.scoreNS - a.scoreNS; });
    
    // Assign the matchpoints to played hands.
    i = 0;
    var n = played.length - 1;
    var p, ties, j;
    while (i <= n)
    {
        p = played[i];
        game = p.game;
        var matchpoints = 0;
        var score = p.scoreNS;
        ties = 0;
        for (j = i + 1; j <= n && score === played[j].scoreNS; ++j)
        {
            ++ties;
            matchpoints += scoring.tie;
        }
        matchpoints += scoring.win * (n - i - ties);
        game.matchpointsNS.value = matchpoints;
        game.matchpointsNS.rank = (i + 1).toString();
        game.matchpointsNS.percentage = (matchpoints / totalMatchpoints) * 100;
        game.matchpointsEW.value = totalMatchpoints - matchpoints;
        game.matchpointsEW.percentage = (game.matchpointsEW.value / totalMatchpoints) * 100;
        if (ties > 0) {
            game.matchpointsNS.rank += '=';
        }
        for (j = 0; j < ties; ++j)
        {
            ++i;
            played[i].game.matchpointsNS = game.matchpointsNS;
            played[i].game.matchpointsEW = game.matchpointsEW;
        }
        ++i;
    }    
    
    // rank EW
    played.sort(function (a,b) { return b.game.matchpointsEW.value - a.game.matchpointsEW.value; });
    i = 0;
    while (i <= n)
    {
        p = played[i];
        game = p.game;
        ties = 0;
        for (j = i + 1; j <= n && game.matchpointsEW.value === played[j].game.matchpointsEW.value; ++j)
        {
            ++ties;
        }
        game.matchpointsEW.rank = (i + 1).toString();
        if (ties > 0) {
            game.matchpointsEW.rank += '=';
        }
        for (j = 0; j < ties; ++j)
        {
            ++i;
            played[i].game.matchpointsEW = game.matchpointsEW;
        }
        ++i;
    }    

    return games;
}

module.exports = {
    standard: function(games) { return matchpoints(games, { win: 2, tie: 1}); },
    ACBL: function(games) { return matchpoints(games, { win: 1.0, tie: 0.5}); }
};

},{}],5:[function(require,module,exports){
'use strict';

function rank(results) {
    // Order the results by descending score (highest score first)
    results = results.slice().sort(function (a,b) { return b.score - a.score; });

    // Assign the rank
    var i = 0, j;
    var n = results.length - 1;
    var maxRank = 0;
    var r;
    while (i <= n)
    {
        r = results[i];
        var score = r.score;
        var ties = 0;
        for (j = i + 1; j <= n && score === results[j].score; ++j)
        {
            ++ties;
        }
        maxRank = i + 1;
        r.rank = maxRank.toString();
        if (ties > 0) {
            r.rank += '=';
        }
        for (j = 0; j < ties; ++j)
        {
            results[++i].rank = r.rank;
        }
        ++i;
    }

    for (i = 0; i <= n; ++i) {
        r = results[i];
        var rank = parseInt(r.rank, 10);
        if (rank === 1) {
            r.scale = 1;
        } else {
            r.scale = (maxRank - rank) / (maxRank);
        }
    }

    return results;
}

module.exports = rank;

},{}],6:[function(require,module,exports){
/*!
 * assertion-error
 * Copyright(c) 2013 Jake Luer <jake@qualiancy.com>
 * MIT Licensed
 */

/*!
 * Return a function that will copy properties from
 * one object to another excluding any originally
 * listed. Returned function will create a new `{}`.
 *
 * @param {String} excluded properties ...
 * @return {Function}
 */

function exclude () {
  var excludes = [].slice.call(arguments);

  function excludeProps (res, obj) {
    Object.keys(obj).forEach(function (key) {
      if (!~excludes.indexOf(key)) res[key] = obj[key];
    });
  }

  return function extendExclude () {
    var args = [].slice.call(arguments)
      , i = 0
      , res = {};

    for (; i < args.length; i++) {
      excludeProps(res, args[i]);
    }

    return res;
  };
};

/*!
 * Primary Exports
 */

module.exports = AssertionError;

/**
 * ### AssertionError
 *
 * An extension of the JavaScript `Error` constructor for
 * assertion and validation scenarios.
 *
 * @param {String} message
 * @param {Object} properties to include (optional)
 * @param {callee} start stack function (optional)
 */

function AssertionError (message, _props, ssf) {
  var extend = exclude('name', 'message', 'stack', 'constructor', 'toJSON')
    , props = extend(_props || {});

  // default values
  this.message = message || 'Unspecified AssertionError';
  this.showDiff = false;

  // copy from properties
  for (var key in props) {
    this[key] = props[key];
  }

  // capture stack trace
  ssf = ssf || arguments.callee;
  if (ssf && Error.captureStackTrace) {
    Error.captureStackTrace(this, ssf);
  } else {
    try {
      throw new Error();
    } catch(e) {
      this.stack = e.stack;
    }
  }
}

/*!
 * Inherit from Error.prototype
 */

AssertionError.prototype = Object.create(Error.prototype);

/*!
 * Statically set name
 */

AssertionError.prototype.name = 'AssertionError';

/*!
 * Ensure correct constructor
 */

AssertionError.prototype.constructor = AssertionError;

/**
 * Allow errors to be converted to JSON for static transfer.
 *
 * @param {Boolean} include stack (default: `true`)
 * @return {Object} object that can be `JSON.stringify`
 */

AssertionError.prototype.toJSON = function (stack) {
  var extend = exclude('constructor', 'toJSON', 'stack')
    , props = extend({ name: this.name }, this);

  // include stack if exists and not turned off
  if (false !== stack && this.stack) {
    props.stack = this.stack;
  }

  return props;
};

},{}],7:[function(require,module,exports){
'use strict'

exports.byteLength = byteLength
exports.toByteArray = toByteArray
exports.fromByteArray = fromByteArray

var lookup = []
var revLookup = []
var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array

var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
for (var i = 0, len = code.length; i < len; ++i) {
  lookup[i] = code[i]
  revLookup[code.charCodeAt(i)] = i
}

revLookup['-'.charCodeAt(0)] = 62
revLookup['_'.charCodeAt(0)] = 63

function placeHoldersCount (b64) {
  var len = b64.length
  if (len % 4 > 0) {
    throw new Error('Invalid string. Length must be a multiple of 4')
  }

  // the number of equal signs (place holders)
  // if there are two placeholders, than the two characters before it
  // represent one byte
  // if there is only one, then the three characters before it represent 2 bytes
  // this is just a cheap hack to not do indexOf twice
  return b64[len - 2] === '=' ? 2 : b64[len - 1] === '=' ? 1 : 0
}

function byteLength (b64) {
  // base64 is 4/3 + up to two characters of the original data
  return b64.length * 3 / 4 - placeHoldersCount(b64)
}

function toByteArray (b64) {
  var i, j, l, tmp, placeHolders, arr
  var len = b64.length
  placeHolders = placeHoldersCount(b64)

  arr = new Arr(len * 3 / 4 - placeHolders)

  // if there are placeholders, only get up to the last complete 4 chars
  l = placeHolders > 0 ? len - 4 : len

  var L = 0

  for (i = 0, j = 0; i < l; i += 4, j += 3) {
    tmp = (revLookup[b64.charCodeAt(i)] << 18) | (revLookup[b64.charCodeAt(i + 1)] << 12) | (revLookup[b64.charCodeAt(i + 2)] << 6) | revLookup[b64.charCodeAt(i + 3)]
    arr[L++] = (tmp >> 16) & 0xFF
    arr[L++] = (tmp >> 8) & 0xFF
    arr[L++] = tmp & 0xFF
  }

  if (placeHolders === 2) {
    tmp = (revLookup[b64.charCodeAt(i)] << 2) | (revLookup[b64.charCodeAt(i + 1)] >> 4)
    arr[L++] = tmp & 0xFF
  } else if (placeHolders === 1) {
    tmp = (revLookup[b64.charCodeAt(i)] << 10) | (revLookup[b64.charCodeAt(i + 1)] << 4) | (revLookup[b64.charCodeAt(i + 2)] >> 2)
    arr[L++] = (tmp >> 8) & 0xFF
    arr[L++] = tmp & 0xFF
  }

  return arr
}

function tripletToBase64 (num) {
  return lookup[num >> 18 & 0x3F] + lookup[num >> 12 & 0x3F] + lookup[num >> 6 & 0x3F] + lookup[num & 0x3F]
}

function encodeChunk (uint8, start, end) {
  var tmp
  var output = []
  for (var i = start; i < end; i += 3) {
    tmp = (uint8[i] << 16) + (uint8[i + 1] << 8) + (uint8[i + 2])
    output.push(tripletToBase64(tmp))
  }
  return output.join('')
}

function fromByteArray (uint8) {
  var tmp
  var len = uint8.length
  var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
  var output = ''
  var parts = []
  var maxChunkLength = 16383 // must be multiple of 3

  // go through the array every three bytes, we'll deal with trailing stuff later
  for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
    parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)))
  }

  // pad the end with zeros, but make sure to not forget the extra bytes
  if (extraBytes === 1) {
    tmp = uint8[len - 1]
    output += lookup[tmp >> 2]
    output += lookup[(tmp << 4) & 0x3F]
    output += '=='
  } else if (extraBytes === 2) {
    tmp = (uint8[len - 2] << 8) + (uint8[len - 1])
    output += lookup[tmp >> 10]
    output += lookup[(tmp >> 4) & 0x3F]
    output += lookup[(tmp << 2) & 0x3F]
    output += '='
  }

  parts.push(output)

  return parts.join('')
}

},{}],8:[function(require,module,exports){
/*!
 * The buffer module from node.js, for the browser.
 *
 * @author   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
 * @license  MIT
 */
/* eslint-disable no-proto */

'use strict'

var base64 = require('base64-js')
var ieee754 = require('ieee754')

exports.Buffer = Buffer
exports.SlowBuffer = SlowBuffer
exports.INSPECT_MAX_BYTES = 50

var K_MAX_LENGTH = 0x7fffffff
exports.kMaxLength = K_MAX_LENGTH

/**
 * If `Buffer.TYPED_ARRAY_SUPPORT`:
 *   === true    Use Uint8Array implementation (fastest)
 *   === false   Print warning and recommend using `buffer` v4.x which has an Object
 *               implementation (most compatible, even IE6)
 *
 * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
 * Opera 11.6+, iOS 4.2+.
 *
 * We report that the browser does not support typed arrays if the are not subclassable
 * using __proto__. Firefox 4-29 lacks support for adding new properties to `Uint8Array`
 * (See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438). IE 10 lacks support
 * for __proto__ and has a buggy typed array implementation.
 */
Buffer.TYPED_ARRAY_SUPPORT = typedArraySupport()

if (!Buffer.TYPED_ARRAY_SUPPORT && typeof console !== 'undefined' &&
    typeof console.error === 'function') {
  console.error(
    'This browser lacks typed array (Uint8Array) support which is required by ' +
    '`buffer` v5.x. Use `buffer` v4.x if you require old browser support.'
  )
}

function typedArraySupport () {
  // Can typed array instances can be augmented?
  try {
    var arr = new Uint8Array(1)
    arr.__proto__ = {__proto__: Uint8Array.prototype, foo: function () { return 42 }}
    return arr.foo() === 42
  } catch (e) {
    return false
  }
}

function createBuffer (length) {
  if (length > K_MAX_LENGTH) {
    throw new RangeError('Invalid typed array length')
  }
  // Return an augmented `Uint8Array` instance
  var buf = new Uint8Array(length)
  buf.__proto__ = Buffer.prototype
  return buf
}

/**
 * The Buffer constructor returns instances of `Uint8Array` that have their
 * prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
 * `Uint8Array`, so the returned instances will have all the node `Buffer` methods
 * and the `Uint8Array` methods. Square bracket notation works as expected -- it
 * returns a single octet.
 *
 * The `Uint8Array` prototype remains unmodified.
 */

function Buffer (arg, encodingOrOffset, length) {
  // Common case.
  if (typeof arg === 'number') {
    if (typeof encodingOrOffset === 'string') {
      throw new Error(
        'If encoding is specified then the first argument must be a string'
      )
    }
    return allocUnsafe(arg)
  }
  return from(arg, encodingOrOffset, length)
}

// Fix subarray() in ES2016. See: https://github.com/feross/buffer/pull/97
if (typeof Symbol !== 'undefined' && Symbol.species &&
    Buffer[Symbol.species] === Buffer) {
  Object.defineProperty(Buffer, Symbol.species, {
    value: null,
    configurable: true,
    enumerable: false,
    writable: false
  })
}

Buffer.poolSize = 8192 // not used by this implementation

function from (value, encodingOrOffset, length) {
  if (typeof value === 'number') {
    throw new TypeError('"value" argument must not be a number')
  }

  if (value instanceof ArrayBuffer) {
    return fromArrayBuffer(value, encodingOrOffset, length)
  }

  if (typeof value === 'string') {
    return fromString(value, encodingOrOffset)
  }

  return fromObject(value)
}

/**
 * Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
 * if value is a number.
 * Buffer.from(str[, encoding])
 * Buffer.from(array)
 * Buffer.from(buffer)
 * Buffer.from(arrayBuffer[, byteOffset[, length]])
 **/
Buffer.from = function (value, encodingOrOffset, length) {
  return from(value, encodingOrOffset, length)
}

// Note: Change prototype *after* Buffer.from is defined to workaround Chrome bug:
// https://github.com/feross/buffer/pull/148
Buffer.prototype.__proto__ = Uint8Array.prototype
Buffer.__proto__ = Uint8Array

function assertSize (size) {
  if (typeof size !== 'number') {
    throw new TypeError('"size" argument must be a number')
  } else if (size < 0) {
    throw new RangeError('"size" argument must not be negative')
  }
}

function alloc (size, fill, encoding) {
  assertSize(size)
  if (size <= 0) {
    return createBuffer(size)
  }
  if (fill !== undefined) {
    // Only pay attention to encoding if it's a string. This
    // prevents accidentally sending in a number that would
    // be interpretted as a start offset.
    return typeof encoding === 'string'
      ? createBuffer(size).fill(fill, encoding)
      : createBuffer(size).fill(fill)
  }
  return createBuffer(size)
}

/**
 * Creates a new filled Buffer instance.
 * alloc(size[, fill[, encoding]])
 **/
Buffer.alloc = function (size, fill, encoding) {
  return alloc(size, fill, encoding)
}

function allocUnsafe (size) {
  assertSize(size)
  return createBuffer(size < 0 ? 0 : checked(size) | 0)
}

/**
 * Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
 * */
Buffer.allocUnsafe = function (size) {
  return allocUnsafe(size)
}
/**
 * Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
 */
Buffer.allocUnsafeSlow = function (size) {
  return allocUnsafe(size)
}

function fromString (string, encoding) {
  if (typeof encoding !== 'string' || encoding === '') {
    encoding = 'utf8'
  }

  if (!Buffer.isEncoding(encoding)) {
    throw new TypeError('"encoding" must be a valid string encoding')
  }

  var length = byteLength(string, encoding) | 0
  var buf = createBuffer(length)

  var actual = buf.write(string, encoding)

  if (actual !== length) {
    // Writing a hex string, for example, that contains invalid characters will
    // cause everything after the first invalid character to be ignored. (e.g.
    // 'abxxcd' will be treated as 'ab')
    buf = buf.slice(0, actual)
  }

  return buf
}

function fromArrayLike (array) {
  var length = array.length < 0 ? 0 : checked(array.length) | 0
  var buf = createBuffer(length)
  for (var i = 0; i < length; i += 1) {
    buf[i] = array[i] & 255
  }
  return buf
}

function fromArrayBuffer (array, byteOffset, length) {
  if (byteOffset < 0 || array.byteLength < byteOffset) {
    throw new RangeError('\'offset\' is out of bounds')
  }

  if (array.byteLength < byteOffset + (length || 0)) {
    throw new RangeError('\'length\' is out of bounds')
  }

  var buf
  if (byteOffset === undefined && length === undefined) {
    buf = new Uint8Array(array)
  } else if (length === undefined) {
    buf = new Uint8Array(array, byteOffset)
  } else {
    buf = new Uint8Array(array, byteOffset, length)
  }

  // Return an augmented `Uint8Array` instance
  buf.__proto__ = Buffer.prototype
  return buf
}

function fromObject (obj) {
  if (Buffer.isBuffer(obj)) {
    var len = checked(obj.length) | 0
    var buf = createBuffer(len)

    if (buf.length === 0) {
      return buf
    }

    obj.copy(buf, 0, 0, len)
    return buf
  }

  if (obj) {
    if (isArrayBufferView(obj) || 'length' in obj) {
      if (typeof obj.length !== 'number' || numberIsNaN(obj.length)) {
        return createBuffer(0)
      }
      return fromArrayLike(obj)
    }

    if (obj.type === 'Buffer' && Array.isArray(obj.data)) {
      return fromArrayLike(obj.data)
    }
  }

  throw new TypeError('First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object.')
}

function checked (length) {
  // Note: cannot use `length < K_MAX_LENGTH` here because that fails when
  // length is NaN (which is otherwise coerced to zero.)
  if (length >= K_MAX_LENGTH) {
    throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
                         'size: 0x' + K_MAX_LENGTH.toString(16) + ' bytes')
  }
  return length | 0
}

function SlowBuffer (length) {
  if (+length != length) { // eslint-disable-line eqeqeq
    length = 0
  }
  return Buffer.alloc(+length)
}

Buffer.isBuffer = function isBuffer (b) {
  return b != null && b._isBuffer === true
}

Buffer.compare = function compare (a, b) {
  if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
    throw new TypeError('Arguments must be Buffers')
  }

  if (a === b) return 0

  var x = a.length
  var y = b.length

  for (var i = 0, len = Math.min(x, y); i < len; ++i) {
    if (a[i] !== b[i]) {
      x = a[i]
      y = b[i]
      break
    }
  }

  if (x < y) return -1
  if (y < x) return 1
  return 0
}

Buffer.isEncoding = function isEncoding (encoding) {
  switch (String(encoding).toLowerCase()) {
    case 'hex':
    case 'utf8':
    case 'utf-8':
    case 'ascii':
    case 'latin1':
    case 'binary':
    case 'base64':
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      return true
    default:
      return false
  }
}

Buffer.concat = function concat (list, length) {
  if (!Array.isArray(list)) {
    throw new TypeError('"list" argument must be an Array of Buffers')
  }

  if (list.length === 0) {
    return Buffer.alloc(0)
  }

  var i
  if (length === undefined) {
    length = 0
    for (i = 0; i < list.length; ++i) {
      length += list[i].length
    }
  }

  var buffer = Buffer.allocUnsafe(length)
  var pos = 0
  for (i = 0; i < list.length; ++i) {
    var buf = list[i]
    if (!Buffer.isBuffer(buf)) {
      throw new TypeError('"list" argument must be an Array of Buffers')
    }
    buf.copy(buffer, pos)
    pos += buf.length
  }
  return buffer
}

function byteLength (string, encoding) {
  if (Buffer.isBuffer(string)) {
    return string.length
  }
  if (isArrayBufferView(string) || string instanceof ArrayBuffer) {
    return string.byteLength
  }
  if (typeof string !== 'string') {
    string = '' + string
  }

  var len = string.length
  if (len === 0) return 0

  // Use a for loop to avoid recursion
  var loweredCase = false
  for (;;) {
    switch (encoding) {
      case 'ascii':
      case 'latin1':
      case 'binary':
        return len
      case 'utf8':
      case 'utf-8':
      case undefined:
        return utf8ToBytes(string).length
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return len * 2
      case 'hex':
        return len >>> 1
      case 'base64':
        return base64ToBytes(string).length
      default:
        if (loweredCase) return utf8ToBytes(string).length // assume utf8
        encoding = ('' + encoding).toLowerCase()
        loweredCase = true
    }
  }
}
Buffer.byteLength = byteLength

function slowToString (encoding, start, end) {
  var loweredCase = false

  // No need to verify that "this.length <= MAX_UINT32" since it's a read-only
  // property of a typed array.

  // This behaves neither like String nor Uint8Array in that we set start/end
  // to their upper/lower bounds if the value passed is out of range.
  // undefined is handled specially as per ECMA-262 6th Edition,
  // Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.
  if (start === undefined || start < 0) {
    start = 0
  }
  // Return early if start > this.length. Done here to prevent potential uint32
  // coercion fail below.
  if (start > this.length) {
    return ''
  }

  if (end === undefined || end > this.length) {
    end = this.length
  }

  if (end <= 0) {
    return ''
  }

  // Force coersion to uint32. This will also coerce falsey/NaN values to 0.
  end >>>= 0
  start >>>= 0

  if (end <= start) {
    return ''
  }

  if (!encoding) encoding = 'utf8'

  while (true) {
    switch (encoding) {
      case 'hex':
        return hexSlice(this, start, end)

      case 'utf8':
      case 'utf-8':
        return utf8Slice(this, start, end)

      case 'ascii':
        return asciiSlice(this, start, end)

      case 'latin1':
      case 'binary':
        return latin1Slice(this, start, end)

      case 'base64':
        return base64Slice(this, start, end)

      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return utf16leSlice(this, start, end)

      default:
        if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
        encoding = (encoding + '').toLowerCase()
        loweredCase = true
    }
  }
}

// This property is used by `Buffer.isBuffer` (and the `is-buffer` npm package)
// to detect a Buffer instance. It's not possible to use `instanceof Buffer`
// reliably in a browserify context because there could be multiple different
// copies of the 'buffer' package in use. This method works even for Buffer
// instances that were created from another copy of the `buffer` package.
// See: https://github.com/feross/buffer/issues/154
Buffer.prototype._isBuffer = true

function swap (b, n, m) {
  var i = b[n]
  b[n] = b[m]
  b[m] = i
}

Buffer.prototype.swap16 = function swap16 () {
  var len = this.length
  if (len % 2 !== 0) {
    throw new RangeError('Buffer size must be a multiple of 16-bits')
  }
  for (var i = 0; i < len; i += 2) {
    swap(this, i, i + 1)
  }
  return this
}

Buffer.prototype.swap32 = function swap32 () {
  var len = this.length
  if (len % 4 !== 0) {
    throw new RangeError('Buffer size must be a multiple of 32-bits')
  }
  for (var i = 0; i < len; i += 4) {
    swap(this, i, i + 3)
    swap(this, i + 1, i + 2)
  }
  return this
}

Buffer.prototype.swap64 = function swap64 () {
  var len = this.length
  if (len % 8 !== 0) {
    throw new RangeError('Buffer size must be a multiple of 64-bits')
  }
  for (var i = 0; i < len; i += 8) {
    swap(this, i, i + 7)
    swap(this, i + 1, i + 6)
    swap(this, i + 2, i + 5)
    swap(this, i + 3, i + 4)
  }
  return this
}

Buffer.prototype.toString = function toString () {
  var length = this.length
  if (length === 0) return ''
  if (arguments.length === 0) return utf8Slice(this, 0, length)
  return slowToString.apply(this, arguments)
}

Buffer.prototype.equals = function equals (b) {
  if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
  if (this === b) return true
  return Buffer.compare(this, b) === 0
}

Buffer.prototype.inspect = function inspect () {
  var str = ''
  var max = exports.INSPECT_MAX_BYTES
  if (this.length > 0) {
    str = this.toString('hex', 0, max).match(/.{2}/g).join(' ')
    if (this.length > max) str += ' ... '
  }
  return '<Buffer ' + str + '>'
}

Buffer.prototype.compare = function compare (target, start, end, thisStart, thisEnd) {
  if (!Buffer.isBuffer(target)) {
    throw new TypeError('Argument must be a Buffer')
  }

  if (start === undefined) {
    start = 0
  }
  if (end === undefined) {
    end = target ? target.length : 0
  }
  if (thisStart === undefined) {
    thisStart = 0
  }
  if (thisEnd === undefined) {
    thisEnd = this.length
  }

  if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) {
    throw new RangeError('out of range index')
  }

  if (thisStart >= thisEnd && start >= end) {
    return 0
  }
  if (thisStart >= thisEnd) {
    return -1
  }
  if (start >= end) {
    return 1
  }

  start >>>= 0
  end >>>= 0
  thisStart >>>= 0
  thisEnd >>>= 0

  if (this === target) return 0

  var x = thisEnd - thisStart
  var y = end - start
  var len = Math.min(x, y)

  var thisCopy = this.slice(thisStart, thisEnd)
  var targetCopy = target.slice(start, end)

  for (var i = 0; i < len; ++i) {
    if (thisCopy[i] !== targetCopy[i]) {
      x = thisCopy[i]
      y = targetCopy[i]
      break
    }
  }

  if (x < y) return -1
  if (y < x) return 1
  return 0
}

// Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
// OR the last index of `val` in `buffer` at offset <= `byteOffset`.
//
// Arguments:
// - buffer - a Buffer to search
// - val - a string, Buffer, or number
// - byteOffset - an index into `buffer`; will be clamped to an int32
// - encoding - an optional encoding, relevant is val is a string
// - dir - true for indexOf, false for lastIndexOf
function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) {
  // Empty buffer means no match
  if (buffer.length === 0) return -1

  // Normalize byteOffset
  if (typeof byteOffset === 'string') {
    encoding = byteOffset
    byteOffset = 0
  } else if (byteOffset > 0x7fffffff) {
    byteOffset = 0x7fffffff
  } else if (byteOffset < -0x80000000) {
    byteOffset = -0x80000000
  }
  byteOffset = +byteOffset  // Coerce to Number.
  if (numberIsNaN(byteOffset)) {
    // byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
    byteOffset = dir ? 0 : (buffer.length - 1)
  }

  // Normalize byteOffset: negative offsets start from the end of the buffer
  if (byteOffset < 0) byteOffset = buffer.length + byteOffset
  if (byteOffset >= buffer.length) {
    if (dir) return -1
    else byteOffset = buffer.length - 1
  } else if (byteOffset < 0) {
    if (dir) byteOffset = 0
    else return -1
  }

  // Normalize val
  if (typeof val === 'string') {
    val = Buffer.from(val, encoding)
  }

  // Finally, search either indexOf (if dir is true) or lastIndexOf
  if (Buffer.isBuffer(val)) {
    // Special case: looking for empty string/buffer always fails
    if (val.length === 0) {
      return -1
    }
    return arrayIndexOf(buffer, val, byteOffset, encoding, dir)
  } else if (typeof val === 'number') {
    val = val & 0xFF // Search for a byte value [0-255]
    if (typeof Uint8Array.prototype.indexOf === 'function') {
      if (dir) {
        return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset)
      } else {
        return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset)
      }
    }
    return arrayIndexOf(buffer, [ val ], byteOffset, encoding, dir)
  }

  throw new TypeError('val must be string, number or Buffer')
}

function arrayIndexOf (arr, val, byteOffset, encoding, dir) {
  var indexSize = 1
  var arrLength = arr.length
  var valLength = val.length

  if (encoding !== undefined) {
    encoding = String(encoding).toLowerCase()
    if (encoding === 'ucs2' || encoding === 'ucs-2' ||
        encoding === 'utf16le' || encoding === 'utf-16le') {
      if (arr.length < 2 || val.length < 2) {
        return -1
      }
      indexSize = 2
      arrLength /= 2
      valLength /= 2
      byteOffset /= 2
    }
  }

  function read (buf, i) {
    if (indexSize === 1) {
      return buf[i]
    } else {
      return buf.readUInt16BE(i * indexSize)
    }
  }

  var i
  if (dir) {
    var foundIndex = -1
    for (i = byteOffset; i < arrLength; i++) {
      if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
        if (foundIndex === -1) foundIndex = i
        if (i - foundIndex + 1 === valLength) return foundIndex * indexSize
      } else {
        if (foundIndex !== -1) i -= i - foundIndex
        foundIndex = -1
      }
    }
  } else {
    if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength
    for (i = byteOffset; i >= 0; i--) {
      var found = true
      for (var j = 0; j < valLength; j++) {
        if (read(arr, i + j) !== read(val, j)) {
          found = false
          break
        }
      }
      if (found) return i
    }
  }

  return -1
}

Buffer.prototype.includes = function includes (val, byteOffset, encoding) {
  return this.indexOf(val, byteOffset, encoding) !== -1
}

Buffer.prototype.indexOf = function indexOf (val, byteOffset, encoding) {
  return bidirectionalIndexOf(this, val, byteOffset, encoding, true)
}

Buffer.prototype.lastIndexOf = function lastIndexOf (val, byteOffset, encoding) {
  return bidirectionalIndexOf(this, val, byteOffset, encoding, false)
}

function hexWrite (buf, string, offset, length) {
  offset = Number(offset) || 0
  var remaining = buf.length - offset
  if (!length) {
    length = remaining
  } else {
    length = Number(length)
    if (length > remaining) {
      length = remaining
    }
  }

  // must be an even number of digits
  var strLen = string.length
  if (strLen % 2 !== 0) throw new TypeError('Invalid hex string')

  if (length > strLen / 2) {
    length = strLen / 2
  }
  for (var i = 0; i < length; ++i) {
    var parsed = parseInt(string.substr(i * 2, 2), 16)
    if (numberIsNaN(parsed)) return i
    buf[offset + i] = parsed
  }
  return i
}

function utf8Write (buf, string, offset, length) {
  return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length)
}

function asciiWrite (buf, string, offset, length) {
  return blitBuffer(asciiToBytes(string), buf, offset, length)
}

function latin1Write (buf, string, offset, length) {
  return asciiWrite(buf, string, offset, length)
}

function base64Write (buf, string, offset, length) {
  return blitBuffer(base64ToBytes(string), buf, offset, length)
}

function ucs2Write (buf, string, offset, length) {
  return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length)
}

Buffer.prototype.write = function write (string, offset, length, encoding) {
  // Buffer#write(string)
  if (offset === undefined) {
    encoding = 'utf8'
    length = this.length
    offset = 0
  // Buffer#write(string, encoding)
  } else if (length === undefined && typeof offset === 'string') {
    encoding = offset
    length = this.length
    offset = 0
  // Buffer#write(string, offset[, length][, encoding])
  } else if (isFinite(offset)) {
    offset = offset >>> 0
    if (isFinite(length)) {
      length = length >>> 0
      if (encoding === undefined) encoding = 'utf8'
    } else {
      encoding = length
      length = undefined
    }
  } else {
    throw new Error(
      'Buffer.write(string, encoding, offset[, length]) is no longer supported'
    )
  }

  var remaining = this.length - offset
  if (length === undefined || length > remaining) length = remaining

  if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) {
    throw new RangeError('Attempt to write outside buffer bounds')
  }

  if (!encoding) encoding = 'utf8'

  var loweredCase = false
  for (;;) {
    switch (encoding) {
      case 'hex':
        return hexWrite(this, string, offset, length)

      case 'utf8':
      case 'utf-8':
        return utf8Write(this, string, offset, length)

      case 'ascii':
        return asciiWrite(this, string, offset, length)

      case 'latin1':
      case 'binary':
        return latin1Write(this, string, offset, length)

      case 'base64':
        // Warning: maxLength not taken into account in base64Write
        return base64Write(this, string, offset, length)

      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return ucs2Write(this, string, offset, length)

      default:
        if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
        encoding = ('' + encoding).toLowerCase()
        loweredCase = true
    }
  }
}

Buffer.prototype.toJSON = function toJSON () {
  return {
    type: 'Buffer',
    data: Array.prototype.slice.call(this._arr || this, 0)
  }
}

function base64Slice (buf, start, end) {
  if (start === 0 && end === buf.length) {
    return base64.fromByteArray(buf)
  } else {
    return base64.fromByteArray(buf.slice(start, end))
  }
}

function utf8Slice (buf, start, end) {
  end = Math.min(buf.length, end)
  var res = []

  var i = start
  while (i < end) {
    var firstByte = buf[i]
    var codePoint = null
    var bytesPerSequence = (firstByte > 0xEF) ? 4
      : (firstByte > 0xDF) ? 3
      : (firstByte > 0xBF) ? 2
      : 1

    if (i + bytesPerSequence <= end) {
      var secondByte, thirdByte, fourthByte, tempCodePoint

      switch (bytesPerSequence) {
        case 1:
          if (firstByte < 0x80) {
            codePoint = firstByte
          }
          break
        case 2:
          secondByte = buf[i + 1]
          if ((secondByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F)
            if (tempCodePoint > 0x7F) {
              codePoint = tempCodePoint
            }
          }
          break
        case 3:
          secondByte = buf[i + 1]
          thirdByte = buf[i + 2]
          if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F)
            if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
              codePoint = tempCodePoint
            }
          }
          break
        case 4:
          secondByte = buf[i + 1]
          thirdByte = buf[i + 2]
          fourthByte = buf[i + 3]
          if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F)
            if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
              codePoint = tempCodePoint
            }
          }
      }
    }

    if (codePoint === null) {
      // we did not generate a valid codePoint so insert a
      // replacement char (U+FFFD) and advance only 1 byte
      codePoint = 0xFFFD
      bytesPerSequence = 1
    } else if (codePoint > 0xFFFF) {
      // encode to utf16 (surrogate pair dance)
      codePoint -= 0x10000
      res.push(codePoint >>> 10 & 0x3FF | 0xD800)
      codePoint = 0xDC00 | codePoint & 0x3FF
    }

    res.push(codePoint)
    i += bytesPerSequence
  }

  return decodeCodePointsArray(res)
}

// Based on http://stackoverflow.com/a/22747272/680742, the browser with
// the lowest limit is Chrome, with 0x10000 args.
// We go 1 magnitude less, for safety
var MAX_ARGUMENTS_LENGTH = 0x1000

function decodeCodePointsArray (codePoints) {
  var len = codePoints.length
  if (len <= MAX_ARGUMENTS_LENGTH) {
    return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
  }

  // Decode in chunks to avoid "call stack size exceeded".
  var res = ''
  var i = 0
  while (i < len) {
    res += String.fromCharCode.apply(
      String,
      codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
    )
  }
  return res
}

function asciiSlice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; ++i) {
    ret += String.fromCharCode(buf[i] & 0x7F)
  }
  return ret
}

function latin1Slice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; ++i) {
    ret += String.fromCharCode(buf[i])
  }
  return ret
}

function hexSlice (buf, start, end) {
  var len = buf.length

  if (!start || start < 0) start = 0
  if (!end || end < 0 || end > len) end = len

  var out = ''
  for (var i = start; i < end; ++i) {
    out += toHex(buf[i])
  }
  return out
}

function utf16leSlice (buf, start, end) {
  var bytes = buf.slice(start, end)
  var res = ''
  for (var i = 0; i < bytes.length; i += 2) {
    res += String.fromCharCode(bytes[i] + (bytes[i + 1] * 256))
  }
  return res
}

Buffer.prototype.slice = function slice (start, end) {
  var len = this.length
  start = ~~start
  end = end === undefined ? len : ~~end

  if (start < 0) {
    start += len
    if (start < 0) start = 0
  } else if (start > len) {
    start = len
  }

  if (end < 0) {
    end += len
    if (end < 0) end = 0
  } else if (end > len) {
    end = len
  }

  if (end < start) end = start

  var newBuf = this.subarray(start, end)
  // Return an augmented `Uint8Array` instance
  newBuf.__proto__ = Buffer.prototype
  return newBuf
}

/*
 * Need to make sure that buffer isn't trying to write out of bounds.
 */
function checkOffset (offset, ext, length) {
  if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint')
  if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length')
}

Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var val = this[offset]
  var mul = 1
  var i = 0
  while (++i < byteLength && (mul *= 0x100)) {
    val += this[offset + i] * mul
  }

  return val
}

Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) {
    checkOffset(offset, byteLength, this.length)
  }

  var val = this[offset + --byteLength]
  var mul = 1
  while (byteLength > 0 && (mul *= 0x100)) {
    val += this[offset + --byteLength] * mul
  }

  return val
}

Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 1, this.length)
  return this[offset]
}

Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  return this[offset] | (this[offset + 1] << 8)
}

Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  return (this[offset] << 8) | this[offset + 1]
}

Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return ((this[offset]) |
      (this[offset + 1] << 8) |
      (this[offset + 2] << 16)) +
      (this[offset + 3] * 0x1000000)
}

Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset] * 0x1000000) +
    ((this[offset + 1] << 16) |
    (this[offset + 2] << 8) |
    this[offset + 3])
}

Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var val = this[offset]
  var mul = 1
  var i = 0
  while (++i < byteLength && (mul *= 0x100)) {
    val += this[offset + i] * mul
  }
  mul *= 0x80

  if (val >= mul) val -= Math.pow(2, 8 * byteLength)

  return val
}

Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var i = byteLength
  var mul = 1
  var val = this[offset + --i]
  while (i > 0 && (mul *= 0x100)) {
    val += this[offset + --i] * mul
  }
  mul *= 0x80

  if (val >= mul) val -= Math.pow(2, 8 * byteLength)

  return val
}

Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 1, this.length)
  if (!(this[offset] & 0x80)) return (this[offset])
  return ((0xff - this[offset] + 1) * -1)
}

Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  var val = this[offset] | (this[offset + 1] << 8)
  return (val & 0x8000) ? val | 0xFFFF0000 : val
}

Buffer.prototype.readInt16BE = function readInt16BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  var val = this[offset + 1] | (this[offset] << 8)
  return (val & 0x8000) ? val | 0xFFFF0000 : val
}

Buffer.prototype.readInt32LE = function readInt32LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset]) |
    (this[offset + 1] << 8) |
    (this[offset + 2] << 16) |
    (this[offset + 3] << 24)
}

Buffer.prototype.readInt32BE = function readInt32BE (o