Repository: evanw/float-toy
Branch: gh-pages
Commit: 1ea0d374417b
Files: 3
Total size: 59.1 KB

Directory structure:
gitextract_qxpuqoni/

├── README.md
├── float16.js
└── index.html

================================================
FILE CONTENTS
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================================================
FILE: README.md
================================================
# Float Toy

Visit [http://evanw.github.io/float-toy/](http://evanw.github.io/float-toy/) to play around.
Use this to build intuition for the IEEE floating-point format.


================================================
FILE: float16.js
================================================
/**
 * @petamoriken/float16 aa4af43 | MIT License - https://git.io/float16
 *
 * @license
 * lodash-es v4.17.15 | MIT License - https://lodash.com/custom-builds
 */

var float16 = (function (exports) {
    'use strict';

    // algorithm: ftp://ftp.fox-toolkit.org/pub/fasthalffloatconversion.pdf
    const buffer = new ArrayBuffer(4);
    const floatView = new Float32Array(buffer);
    const uint32View = new Uint32Array(buffer);
    const baseTable = new Uint32Array(512);
    const shiftTable = new Uint32Array(512);

    for (let i = 0; i < 256; ++i) {
      const e = i - 127; // very small number (0, -0)

      if (e < -27) {
        baseTable[i | 0x000] = 0x0000;
        baseTable[i | 0x100] = 0x8000;
        shiftTable[i | 0x000] = 24;
        shiftTable[i | 0x100] = 24; // small number (denorm)
      } else if (e < -14) {
        baseTable[i | 0x000] = 0x0400 >> -e - 14;
        baseTable[i | 0x100] = 0x0400 >> -e - 14 | 0x8000;
        shiftTable[i | 0x000] = -e - 1;
        shiftTable[i | 0x100] = -e - 1; // normal number
      } else if (e <= 15) {
        baseTable[i | 0x000] = e + 15 << 10;
        baseTable[i | 0x100] = e + 15 << 10 | 0x8000;
        shiftTable[i | 0x000] = 13;
        shiftTable[i | 0x100] = 13; // large number (Infinity, -Infinity)
      } else if (e < 128) {
        baseTable[i | 0x000] = 0x7c00;
        baseTable[i | 0x100] = 0xfc00;
        shiftTable[i | 0x000] = 24;
        shiftTable[i | 0x100] = 24; // stay (NaN, Infinity, -Infinity)
      } else {
        baseTable[i | 0x000] = 0x7c00;
        baseTable[i | 0x100] = 0xfc00;
        shiftTable[i | 0x000] = 13;
        shiftTable[i | 0x100] = 13;
      }
    }
    /**
     * round a number to a half float number bits.
     * @param {number} num
     */


    function roundToFloat16Bits(num) {
      floatView[0] = num;
      const f = uint32View[0];
      const e = f >> 23 & 0x1ff;
      return baseTable[e] + ((f & 0x007fffff) >> shiftTable[e]);
    }
    const mantissaTable = new Uint32Array(2048);
    const exponentTable = new Uint32Array(64);
    const offsetTable = new Uint32Array(64);
    mantissaTable[0] = 0;

    for (let i = 1; i < 1024; ++i) {
      let m = i << 13; // zero pad mantissa bits

      let e = 0; // zero exponent
      // normalized

      while ((m & 0x00800000) === 0) {
        e -= 0x00800000; // decrement exponent

        m <<= 1;
      }

      m &= ~0x00800000; // clear leading 1 bit

      e += 0x38800000; // adjust bias

      mantissaTable[i] = m | e;
    }

    for (let i = 1024; i < 2048; ++i) {
      mantissaTable[i] = 0x38000000 + (i - 1024 << 13);
    }

    exponentTable[0] = 0;

    for (let i = 1; i < 31; ++i) {
      exponentTable[i] = i << 23;
    }

    exponentTable[31] = 0x47800000;
    exponentTable[32] = 0x80000000;

    for (let i = 33; i < 63; ++i) {
      exponentTable[i] = 0x80000000 + (i - 32 << 23);
    }

    exponentTable[63] = 0xc7800000;
    offsetTable[0] = 0;

    for (let i = 1; i < 64; ++i) {
      if (i === 32) {
        offsetTable[i] = 0;
      } else {
        offsetTable[i] = 1024;
      }
    }
    /**
     * convert a half float number bits to a number.
     * @param {number} float16bits - half float number bits
     */


    function convertToNumber(float16bits) {
      const m = float16bits >> 10;
      uint32View[0] = mantissaTable[offsetTable[m] + (float16bits & 0x3ff)] + exponentTable[m];
      return floatView[0];
    }

    /**
     * returns the nearest half precision float representation of a number.
     * @param {number} num
     */

    function hfround(num) {
      num = Number(num); // for optimization

      if (!Number.isFinite(num) || num === 0) {
        return num;
      }

      const x16 = roundToFloat16Bits(num);
      return convertToNumber(x16);
    }

    function ToInteger(num) {
      if (typeof num !== "number") num = Number(num);
      if (Number.isNaN(num)) num = 0;
      return Math.trunc(num);
    }
    function defaultCompareFunction(x, y) {
      const [isNaN_x, isNaN_y] = [Number.isNaN(x), Number.isNaN(y)];
      if (isNaN_x && isNaN_y) return 0;
      if (isNaN_x) return 1;
      if (isNaN_y) return -1;
      if (x < y) return -1;
      if (x > y) return 1;

      if (x === 0 && y === 0) {
        const [isPlusZero_x, isPlusZero_y] = [Object.is(x, 0), Object.is(y, 0)];
        if (!isPlusZero_x && isPlusZero_y) return -1;
        if (isPlusZero_x && !isPlusZero_y) return 1;
      }

      return 0;
    }

    /** Detect free variable `global` from Node.js. */
    var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;

    /** Detect free variable `self`. */

    var freeSelf = typeof self == 'object' && self && self.Object === Object && self;
    /** Used as a reference to the global object. */

    var root = freeGlobal || freeSelf || Function('return this')();

    /** Built-in value references. */

    var Symbol$1 = root.Symbol;

    /** Used for built-in method references. */

    var objectProto = Object.prototype;
    /** Used to check objects for own properties. */

    var hasOwnProperty = objectProto.hasOwnProperty;
    /**
     * Used to resolve the
     * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
     * of values.
     */

    var nativeObjectToString = objectProto.toString;
    /** Built-in value references. */

    var symToStringTag = Symbol$1 ? Symbol$1.toStringTag : undefined;
    /**
     * A specialized version of `baseGetTag` which ignores `Symbol.toStringTag` values.
     *
     * @private
     * @param {*} value The value to query.
     * @returns {string} Returns the raw `toStringTag`.
     */

    function getRawTag(value) {
      var isOwn = hasOwnProperty.call(value, symToStringTag),
          tag = value[symToStringTag];

      try {
        value[symToStringTag] = undefined;
        var unmasked = true;
      } catch (e) {}

      var result = nativeObjectToString.call(value);

      if (unmasked) {
        if (isOwn) {
          value[symToStringTag] = tag;
        } else {
          delete value[symToStringTag];
        }
      }

      return result;
    }

    /** Used for built-in method references. */
    var objectProto$1 = Object.prototype;
    /**
     * Used to resolve the
     * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
     * of values.
     */

    var nativeObjectToString$1 = objectProto$1.toString;
    /**
     * Converts `value` to a string using `Object.prototype.toString`.
     *
     * @private
     * @param {*} value The value to convert.
     * @returns {string} Returns the converted string.
     */

    function objectToString(value) {
      return nativeObjectToString$1.call(value);
    }

    /** `Object#toString` result references. */

    var nullTag = '[object Null]',
        undefinedTag = '[object Undefined]';
    /** Built-in value references. */

    var symToStringTag$1 = Symbol$1 ? Symbol$1.toStringTag : undefined;
    /**
     * The base implementation of `getTag` without fallbacks for buggy environments.
     *
     * @private
     * @param {*} value The value to query.
     * @returns {string} Returns the `toStringTag`.
     */

    function baseGetTag(value) {
      if (value == null) {
        return value === undefined ? undefinedTag : nullTag;
      }

      return symToStringTag$1 && symToStringTag$1 in Object(value) ? getRawTag(value) : objectToString(value);
    }

    /**
     * Checks if `value` is object-like. A value is object-like if it's not `null`
     * and has a `typeof` result of "object".
     *
     * @static
     * @memberOf _
     * @since 4.0.0
     * @category Lang
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
     * @example
     *
     * _.isObjectLike({});
     * // => true
     *
     * _.isObjectLike([1, 2, 3]);
     * // => true
     *
     * _.isObjectLike(_.noop);
     * // => false
     *
     * _.isObjectLike(null);
     * // => false
     */
    function isObjectLike(value) {
      return value != null && typeof value == 'object';
    }

    var arrayBufferTag = '[object ArrayBuffer]';
    /**
     * The base implementation of `_.isArrayBuffer` without Node.js optimizations.
     *
     * @private
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is an array buffer, else `false`.
     */

    function baseIsArrayBuffer(value) {
      return isObjectLike(value) && baseGetTag(value) == arrayBufferTag;
    }

    /**
     * The base implementation of `_.unary` without support for storing metadata.
     *
     * @private
     * @param {Function} func The function to cap arguments for.
     * @returns {Function} Returns the new capped function.
     */
    function baseUnary(func) {
      return function (value) {
        return func(value);
      };
    }

    /** Detect free variable `exports`. */

    var freeExports = typeof exports == 'object' && exports && !exports.nodeType && exports;
    /** Detect free variable `module`. */

    var freeModule = freeExports && typeof module == 'object' && module && !module.nodeType && module;
    /** Detect the popular CommonJS extension `module.exports`. */

    var moduleExports = freeModule && freeModule.exports === freeExports;
    /** Detect free variable `process` from Node.js. */

    var freeProcess = moduleExports && freeGlobal.process;
    /** Used to access faster Node.js helpers. */

    var nodeUtil = function () {
      try {
        // Use `util.types` for Node.js 10+.
        var types = freeModule && freeModule.require && freeModule.require('util').types;

        if (types) {
          return types;
        } // Legacy `process.binding('util')` for Node.js < 10.


        return freeProcess && freeProcess.binding && freeProcess.binding('util');
      } catch (e) {}
    }();

    /* Node.js helper references. */

    var nodeIsArrayBuffer = nodeUtil && nodeUtil.isArrayBuffer;
    /**
     * Checks if `value` is classified as an `ArrayBuffer` object.
     *
     * @static
     * @memberOf _
     * @since 4.3.0
     * @category Lang
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is an array buffer, else `false`.
     * @example
     *
     * _.isArrayBuffer(new ArrayBuffer(2));
     * // => true
     *
     * _.isArrayBuffer(new Array(2));
     * // => false
     */

    var isArrayBuffer = nodeIsArrayBuffer ? baseUnary(nodeIsArrayBuffer) : baseIsArrayBuffer;

    function isDataView(view) {
      return view instanceof DataView;
    }
    function isStringNumberKey(key) {
      return typeof key === "string" && key === ToInteger(key) + "";
    }

    function createPrivateStorage() {
      const wm = new WeakMap();
      return self => {
        let obj = wm.get(self);

        if (obj) {
          return obj;
        } else {
          obj = Object.create(null);
          wm.set(self, obj);
          return obj;
        }
      };
    }

    /**
     * Checks if `value` is the
     * [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
     * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
     *
     * @static
     * @memberOf _
     * @since 0.1.0
     * @category Lang
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is an object, else `false`.
     * @example
     *
     * _.isObject({});
     * // => true
     *
     * _.isObject([1, 2, 3]);
     * // => true
     *
     * _.isObject(_.noop);
     * // => true
     *
     * _.isObject(null);
     * // => false
     */
    function isObject(value) {
      var type = typeof value;
      return value != null && (type == 'object' || type == 'function');
    }

    /** `Object#toString` result references. */

    var asyncTag = '[object AsyncFunction]',
        funcTag = '[object Function]',
        genTag = '[object GeneratorFunction]',
        proxyTag = '[object Proxy]';
    /**
     * Checks if `value` is classified as a `Function` object.
     *
     * @static
     * @memberOf _
     * @since 0.1.0
     * @category Lang
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is a function, else `false`.
     * @example
     *
     * _.isFunction(_);
     * // => true
     *
     * _.isFunction(/abc/);
     * // => false
     */

    function isFunction(value) {
      if (!isObject(value)) {
        return false;
      } // The use of `Object#toString` avoids issues with the `typeof` operator
      // in Safari 9 which returns 'object' for typed arrays and other constructors.


      var tag = baseGetTag(value);
      return tag == funcTag || tag == genTag || tag == asyncTag || tag == proxyTag;
    }

    /** Used to detect overreaching core-js shims. */

    var coreJsData = root['__core-js_shared__'];

    /** Used to detect methods masquerading as native. */

    var maskSrcKey = function () {
      var uid = /[^.]+$/.exec(coreJsData && coreJsData.keys && coreJsData.keys.IE_PROTO || '');
      return uid ? 'Symbol(src)_1.' + uid : '';
    }();
    /**
     * Checks if `func` has its source masked.
     *
     * @private
     * @param {Function} func The function to check.
     * @returns {boolean} Returns `true` if `func` is masked, else `false`.
     */


    function isMasked(func) {
      return !!maskSrcKey && maskSrcKey in func;
    }

    /** Used for built-in method references. */
    var funcProto = Function.prototype;
    /** Used to resolve the decompiled source of functions. */

    var funcToString = funcProto.toString;
    /**
     * Converts `func` to its source code.
     *
     * @private
     * @param {Function} func The function to convert.
     * @returns {string} Returns the source code.
     */

    function toSource(func) {
      if (func != null) {
        try {
          return funcToString.call(func);
        } catch (e) {}

        try {
          return func + '';
        } catch (e) {}
      }

      return '';
    }

    /**
     * Used to match `RegExp`
     * [syntax characters](http://ecma-international.org/ecma-262/7.0/#sec-patterns).
     */

    var reRegExpChar = /[\\^$.*+?()[\]{}|]/g;
    /** Used to detect host constructors (Safari). */

    var reIsHostCtor = /^\[object .+?Constructor\]$/;
    /** Used for built-in method references. */

    var funcProto$1 = Function.prototype,
        objectProto$2 = Object.prototype;
    /** Used to resolve the decompiled source of functions. */

    var funcToString$1 = funcProto$1.toString;
    /** Used to check objects for own properties. */

    var hasOwnProperty$1 = objectProto$2.hasOwnProperty;
    /** Used to detect if a method is native. */

    var reIsNative = RegExp('^' + funcToString$1.call(hasOwnProperty$1).replace(reRegExpChar, '\\$&').replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$');
    /**
     * The base implementation of `_.isNative` without bad shim checks.
     *
     * @private
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is a native function,
     *  else `false`.
     */

    function baseIsNative(value) {
      if (!isObject(value) || isMasked(value)) {
        return false;
      }

      var pattern = isFunction(value) ? reIsNative : reIsHostCtor;
      return pattern.test(toSource(value));
    }

    /**
     * Gets the value at `key` of `object`.
     *
     * @private
     * @param {Object} [object] The object to query.
     * @param {string} key The key of the property to get.
     * @returns {*} Returns the property value.
     */
    function getValue(object, key) {
      return object == null ? undefined : object[key];
    }

    /**
     * Gets the native function at `key` of `object`.
     *
     * @private
     * @param {Object} object The object to query.
     * @param {string} key The key of the method to get.
     * @returns {*} Returns the function if it's native, else `undefined`.
     */

    function getNative(object, key) {
      var value = getValue(object, key);
      return baseIsNative(value) ? value : undefined;
    }

    /* Built-in method references that are verified to be native. */

    var nativeCreate = getNative(Object, 'create');

    /**
     * Removes all key-value entries from the hash.
     *
     * @private
     * @name clear
     * @memberOf Hash
     */

    function hashClear() {
      this.__data__ = nativeCreate ? nativeCreate(null) : {};
      this.size = 0;
    }

    /**
     * Removes `key` and its value from the hash.
     *
     * @private
     * @name delete
     * @memberOf Hash
     * @param {Object} hash The hash to modify.
     * @param {string} key The key of the value to remove.
     * @returns {boolean} Returns `true` if the entry was removed, else `false`.
     */
    function hashDelete(key) {
      var result = this.has(key) && delete this.__data__[key];
      this.size -= result ? 1 : 0;
      return result;
    }

    /** Used to stand-in for `undefined` hash values. */

    var HASH_UNDEFINED = '__lodash_hash_undefined__';
    /** Used for built-in method references. */

    var objectProto$3 = Object.prototype;
    /** Used to check objects for own properties. */

    var hasOwnProperty$2 = objectProto$3.hasOwnProperty;
    /**
     * Gets the hash value for `key`.
     *
     * @private
     * @name get
     * @memberOf Hash
     * @param {string} key The key of the value to get.
     * @returns {*} Returns the entry value.
     */

    function hashGet(key) {
      var data = this.__data__;

      if (nativeCreate) {
        var result = data[key];
        return result === HASH_UNDEFINED ? undefined : result;
      }

      return hasOwnProperty$2.call(data, key) ? data[key] : undefined;
    }

    /** Used for built-in method references. */

    var objectProto$4 = Object.prototype;
    /** Used to check objects for own properties. */

    var hasOwnProperty$3 = objectProto$4.hasOwnProperty;
    /**
     * Checks if a hash value for `key` exists.
     *
     * @private
     * @name has
     * @memberOf Hash
     * @param {string} key The key of the entry to check.
     * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
     */

    function hashHas(key) {
      var data = this.__data__;
      return nativeCreate ? data[key] !== undefined : hasOwnProperty$3.call(data, key);
    }

    /** Used to stand-in for `undefined` hash values. */

    var HASH_UNDEFINED$1 = '__lodash_hash_undefined__';
    /**
     * Sets the hash `key` to `value`.
     *
     * @private
     * @name set
     * @memberOf Hash
     * @param {string} key The key of the value to set.
     * @param {*} value The value to set.
     * @returns {Object} Returns the hash instance.
     */

    function hashSet(key, value) {
      var data = this.__data__;
      this.size += this.has(key) ? 0 : 1;
      data[key] = nativeCreate && value === undefined ? HASH_UNDEFINED$1 : value;
      return this;
    }

    /**
     * Creates a hash object.
     *
     * @private
     * @constructor
     * @param {Array} [entries] The key-value pairs to cache.
     */

    function Hash(entries) {
      var index = -1,
          length = entries == null ? 0 : entries.length;
      this.clear();

      while (++index < length) {
        var entry = entries[index];
        this.set(entry[0], entry[1]);
      }
    } // Add methods to `Hash`.


    Hash.prototype.clear = hashClear;
    Hash.prototype['delete'] = hashDelete;
    Hash.prototype.get = hashGet;
    Hash.prototype.has = hashHas;
    Hash.prototype.set = hashSet;

    /**
     * Removes all key-value entries from the list cache.
     *
     * @private
     * @name clear
     * @memberOf ListCache
     */
    function listCacheClear() {
      this.__data__ = [];
      this.size = 0;
    }

    /**
     * Performs a
     * [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero)
     * comparison between two values to determine if they are equivalent.
     *
     * @static
     * @memberOf _
     * @since 4.0.0
     * @category Lang
     * @param {*} value The value to compare.
     * @param {*} other The other value to compare.
     * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
     * @example
     *
     * var object = { 'a': 1 };
     * var other = { 'a': 1 };
     *
     * _.eq(object, object);
     * // => true
     *
     * _.eq(object, other);
     * // => false
     *
     * _.eq('a', 'a');
     * // => true
     *
     * _.eq('a', Object('a'));
     * // => false
     *
     * _.eq(NaN, NaN);
     * // => true
     */
    function eq(value, other) {
      return value === other || value !== value && other !== other;
    }

    /**
     * Gets the index at which the `key` is found in `array` of key-value pairs.
     *
     * @private
     * @param {Array} array The array to inspect.
     * @param {*} key The key to search for.
     * @returns {number} Returns the index of the matched value, else `-1`.
     */

    function assocIndexOf(array, key) {
      var length = array.length;

      while (length--) {
        if (eq(array[length][0], key)) {
          return length;
        }
      }

      return -1;
    }

    /** Used for built-in method references. */

    var arrayProto = Array.prototype;
    /** Built-in value references. */

    var splice = arrayProto.splice;
    /**
     * Removes `key` and its value from the list cache.
     *
     * @private
     * @name delete
     * @memberOf ListCache
     * @param {string} key The key of the value to remove.
     * @returns {boolean} Returns `true` if the entry was removed, else `false`.
     */

    function listCacheDelete(key) {
      var data = this.__data__,
          index = assocIndexOf(data, key);

      if (index < 0) {
        return false;
      }

      var lastIndex = data.length - 1;

      if (index == lastIndex) {
        data.pop();
      } else {
        splice.call(data, index, 1);
      }

      --this.size;
      return true;
    }

    /**
     * Gets the list cache value for `key`.
     *
     * @private
     * @name get
     * @memberOf ListCache
     * @param {string} key The key of the value to get.
     * @returns {*} Returns the entry value.
     */

    function listCacheGet(key) {
      var data = this.__data__,
          index = assocIndexOf(data, key);
      return index < 0 ? undefined : data[index][1];
    }

    /**
     * Checks if a list cache value for `key` exists.
     *
     * @private
     * @name has
     * @memberOf ListCache
     * @param {string} key The key of the entry to check.
     * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
     */

    function listCacheHas(key) {
      return assocIndexOf(this.__data__, key) > -1;
    }

    /**
     * Sets the list cache `key` to `value`.
     *
     * @private
     * @name set
     * @memberOf ListCache
     * @param {string} key The key of the value to set.
     * @param {*} value The value to set.
     * @returns {Object} Returns the list cache instance.
     */

    function listCacheSet(key, value) {
      var data = this.__data__,
          index = assocIndexOf(data, key);

      if (index < 0) {
        ++this.size;
        data.push([key, value]);
      } else {
        data[index][1] = value;
      }

      return this;
    }

    /**
     * Creates an list cache object.
     *
     * @private
     * @constructor
     * @param {Array} [entries] The key-value pairs to cache.
     */

    function ListCache(entries) {
      var index = -1,
          length = entries == null ? 0 : entries.length;
      this.clear();

      while (++index < length) {
        var entry = entries[index];
        this.set(entry[0], entry[1]);
      }
    } // Add methods to `ListCache`.


    ListCache.prototype.clear = listCacheClear;
    ListCache.prototype['delete'] = listCacheDelete;
    ListCache.prototype.get = listCacheGet;
    ListCache.prototype.has = listCacheHas;
    ListCache.prototype.set = listCacheSet;

    /* Built-in method references that are verified to be native. */

    var Map = getNative(root, 'Map');

    /**
     * Removes all key-value entries from the map.
     *
     * @private
     * @name clear
     * @memberOf MapCache
     */

    function mapCacheClear() {
      this.size = 0;
      this.__data__ = {
        'hash': new Hash(),
        'map': new (Map || ListCache)(),
        'string': new Hash()
      };
    }

    /**
     * Checks if `value` is suitable for use as unique object key.
     *
     * @private
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is suitable, else `false`.
     */
    function isKeyable(value) {
      var type = typeof value;
      return type == 'string' || type == 'number' || type == 'symbol' || type == 'boolean' ? value !== '__proto__' : value === null;
    }

    /**
     * Gets the data for `map`.
     *
     * @private
     * @param {Object} map The map to query.
     * @param {string} key The reference key.
     * @returns {*} Returns the map data.
     */

    function getMapData(map, key) {
      var data = map.__data__;
      return isKeyable(key) ? data[typeof key == 'string' ? 'string' : 'hash'] : data.map;
    }

    /**
     * Removes `key` and its value from the map.
     *
     * @private
     * @name delete
     * @memberOf MapCache
     * @param {string} key The key of the value to remove.
     * @returns {boolean} Returns `true` if the entry was removed, else `false`.
     */

    function mapCacheDelete(key) {
      var result = getMapData(this, key)['delete'](key);
      this.size -= result ? 1 : 0;
      return result;
    }

    /**
     * Gets the map value for `key`.
     *
     * @private
     * @name get
     * @memberOf MapCache
     * @param {string} key The key of the value to get.
     * @returns {*} Returns the entry value.
     */

    function mapCacheGet(key) {
      return getMapData(this, key).get(key);
    }

    /**
     * Checks if a map value for `key` exists.
     *
     * @private
     * @name has
     * @memberOf MapCache
     * @param {string} key The key of the entry to check.
     * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
     */

    function mapCacheHas(key) {
      return getMapData(this, key).has(key);
    }

    /**
     * Sets the map `key` to `value`.
     *
     * @private
     * @name set
     * @memberOf MapCache
     * @param {string} key The key of the value to set.
     * @param {*} value The value to set.
     * @returns {Object} Returns the map cache instance.
     */

    function mapCacheSet(key, value) {
      var data = getMapData(this, key),
          size = data.size;
      data.set(key, value);
      this.size += data.size == size ? 0 : 1;
      return this;
    }

    /**
     * Creates a map cache object to store key-value pairs.
     *
     * @private
     * @constructor
     * @param {Array} [entries] The key-value pairs to cache.
     */

    function MapCache(entries) {
      var index = -1,
          length = entries == null ? 0 : entries.length;
      this.clear();

      while (++index < length) {
        var entry = entries[index];
        this.set(entry[0], entry[1]);
      }
    } // Add methods to `MapCache`.


    MapCache.prototype.clear = mapCacheClear;
    MapCache.prototype['delete'] = mapCacheDelete;
    MapCache.prototype.get = mapCacheGet;
    MapCache.prototype.has = mapCacheHas;
    MapCache.prototype.set = mapCacheSet;

    /** Error message constants. */

    var FUNC_ERROR_TEXT = 'Expected a function';
    /**
     * Creates a function that memoizes the result of `func`. If `resolver` is
     * provided, it determines the cache key for storing the result based on the
     * arguments provided to the memoized function. By default, the first argument
     * provided to the memoized function is used as the map cache key. The `func`
     * is invoked with the `this` binding of the memoized function.
     *
     * **Note:** The cache is exposed as the `cache` property on the memoized
     * function. Its creation may be customized by replacing the `_.memoize.Cache`
     * constructor with one whose instances implement the
     * [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object)
     * method interface of `clear`, `delete`, `get`, `has`, and `set`.
     *
     * @static
     * @memberOf _
     * @since 0.1.0
     * @category Function
     * @param {Function} func The function to have its output memoized.
     * @param {Function} [resolver] The function to resolve the cache key.
     * @returns {Function} Returns the new memoized function.
     * @example
     *
     * var object = { 'a': 1, 'b': 2 };
     * var other = { 'c': 3, 'd': 4 };
     *
     * var values = _.memoize(_.values);
     * values(object);
     * // => [1, 2]
     *
     * values(other);
     * // => [3, 4]
     *
     * object.a = 2;
     * values(object);
     * // => [1, 2]
     *
     * // Modify the result cache.
     * values.cache.set(object, ['a', 'b']);
     * values(object);
     * // => ['a', 'b']
     *
     * // Replace `_.memoize.Cache`.
     * _.memoize.Cache = WeakMap;
     */

    function memoize(func, resolver) {
      if (typeof func != 'function' || resolver != null && typeof resolver != 'function') {
        throw new TypeError(FUNC_ERROR_TEXT);
      }

      var memoized = function memoized() {
        var args = arguments,
            key = resolver ? resolver.apply(this, args) : args[0],
            cache = memoized.cache;

        if (cache.has(key)) {
          return cache.get(key);
        }

        var result = func.apply(this, args);
        memoized.cache = cache.set(key, result) || cache;
        return result;
      };

      memoized.cache = new (memoize.Cache || MapCache)();
      return memoized;
    } // Expose `MapCache`.


    memoize.Cache = MapCache;

    // JavaScriptCore bug: https://bugs.webkit.org/show_bug.cgi?id=171606
    const isTypedArrayIndexedPropertyWritable = Object.getOwnPropertyDescriptor(new Uint8Array(1), 0).writable;

    const _ = createPrivateStorage();

    function isFloat16Array(target) {
      return target instanceof Float16Array;
    }

    function assertFloat16Array(target) {
      if (!isFloat16Array(target)) {
        throw new TypeError("This is not a Float16Array");
      }
    }

    function isDefaultFloat16ArrayMethods(target) {
      return typeof target === "function" && defaultFloat16ArrayMethods.has(target);
    }

    function copyToArray(float16bits) {
      const length = float16bits.length;
      const array = new Array(length);

      for (let i = 0; i < length; ++i) {
        array[i] = convertToNumber(float16bits[i]);
      }

      return array;
    } // proxy handler


    const applyHandler = {
      apply(func, thisArg, args) {
        // peel off proxy
        if (isFloat16Array(thisArg) && isDefaultFloat16ArrayMethods(func)) return Reflect.apply(func, _(thisArg).target, args);
        return Reflect.apply(func, thisArg, args);
      }

    };
    const handler = {
      get(target, key) {
        let wrapper = null;

        if (!isTypedArrayIndexedPropertyWritable) {
          wrapper = target;
          target = _(wrapper).target;
        }

        if (isStringNumberKey(key)) {
          return Reflect.has(target, key) ? convertToNumber(Reflect.get(target, key)) : undefined;
        } else {
          const ret = wrapper !== null && Reflect.has(wrapper, key) ? Reflect.get(wrapper, key) : Reflect.get(target, key);
          if (typeof ret !== "function") return ret; // TypedArray methods can't be called by Proxy Object

          let proxy = _(ret).proxy;

          if (proxy === undefined) {
            proxy = _(ret).proxy = new Proxy(ret, applyHandler);
          }

          return proxy;
        }
      },

      set(target, key, value) {
        let wrapper = null;

        if (!isTypedArrayIndexedPropertyWritable) {
          wrapper = target;
          target = _(wrapper).target;
        }

        if (isStringNumberKey(key)) {
          return Reflect.set(target, key, roundToFloat16Bits(value));
        } else {
          // frozen object can't change prototype property
          if (wrapper !== null && (!Reflect.has(target, key) || Object.isFrozen(wrapper))) {
            return Reflect.set(wrapper, key, value);
          } else {
            return Reflect.set(target, key, value);
          }
        }
      }

    };

    if (!isTypedArrayIndexedPropertyWritable) {
      handler.getPrototypeOf = wrapper => Reflect.getPrototypeOf(_(wrapper).target);

      handler.setPrototypeOf = (wrapper, prototype) => Reflect.setPrototypeOf(_(wrapper).target, prototype);

      handler.defineProperty = (wrapper, key, descriptor) => {
        const target = _(wrapper).target;

        return !Reflect.has(target, key) || Object.isFrozen(wrapper) ? Reflect.defineProperty(wrapper, key, descriptor) : Reflect.defineProperty(target, key, descriptor);
      };

      handler.deleteProperty = (wrapper, key) => {
        const target = _(wrapper).target;

        return Reflect.has(wrapper, key) ? Reflect.deleteProperty(wrapper, key) : Reflect.deleteProperty(target, key);
      };

      handler.has = (wrapper, key) => Reflect.has(wrapper, key) || Reflect.has(_(wrapper).target, key);

      handler.isExtensible = wrapper => Reflect.isExtensible(wrapper);

      handler.preventExtensions = wrapper => Reflect.preventExtensions(wrapper);

      handler.getOwnPropertyDescriptor = (wrapper, key) => Reflect.getOwnPropertyDescriptor(wrapper, key);

      handler.ownKeys = wrapper => Reflect.ownKeys(wrapper);
    }

    class Float16Array extends Uint16Array {
      constructor(input, byteOffset, length) {
        // input Float16Array
        if (isFloat16Array(input)) {
          super(_(input).target); // 22.2.1.3, 22.2.1.4 TypedArray, Array, ArrayLike, Iterable
        } else if (input !== null && typeof input === "object" && !isArrayBuffer(input)) {
          // if input is not ArrayLike and Iterable, get Array
          const arrayLike = !Reflect.has(input, "length") && input[Symbol.iterator] !== undefined ? [...input] : input;
          const length = arrayLike.length;
          super(length);

          for (let i = 0; i < length; ++i) {
            // super (Uint16Array)
            this[i] = roundToFloat16Bits(arrayLike[i]);
          } // 22.2.1.2, 22.2.1.5 primitive, ArrayBuffer

        } else {
          switch (arguments.length) {
            case 0:
              super();
              break;

            case 1:
              super(input);
              break;

            case 2:
              super(input, byteOffset);
              break;

            case 3:
              super(input, byteOffset, length);
              break;

            default:
              super(...arguments);
          }
        }

        let proxy;

        if (isTypedArrayIndexedPropertyWritable) {
          proxy = new Proxy(this, handler);
        } else {
          const wrapper = Object.create(null);
          _(wrapper).target = this;
          proxy = new Proxy(wrapper, handler);
        } // proxy private storage


        _(proxy).target = this; // this private storage

        _(this).proxy = proxy;
        return proxy;
      } // static methods


      static from(src) {
        if ((arguments.length <= 1 ? 0 : arguments.length - 1) === 0) return new Float16Array(Uint16Array.from(src, roundToFloat16Bits).buffer);
        const mapFunc = arguments.length <= 1 ? undefined : arguments[1];
        const thisArg = arguments.length <= 2 ? undefined : arguments[2];
        return new Float16Array(Uint16Array.from(src, function (val) {
          for (var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
            args[_key - 1] = arguments[_key];
          }

          return roundToFloat16Bits(mapFunc.call(this, val, ...args));
        }, thisArg).buffer);
      }

      static of() {
        for (var _len2 = arguments.length, args = new Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
          args[_key2] = arguments[_key2];
        }

        return new Float16Array(args);
      } // iterate methods


      *[Symbol.iterator]() {
        for (const val of super[Symbol.iterator]()) {
          yield convertToNumber(val);
        }
      }

      keys() {
        return super.keys();
      }

      *values() {
        for (const val of super.values()) {
          yield convertToNumber(val);
        }
      }

      *entries() {
        for (const [i, val] of super.entries()) {
          yield [i, convertToNumber(val)];
        }
      } // functional methods


      map(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];
        const array = [];

        for (let i = 0, l = this.length; i < l; ++i) {
          const val = convertToNumber(this[i]);
          array.push(callback.call(thisArg, val, i, _(this).proxy));
        }

        return new Float16Array(array);
      }

      filter(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];
        const array = [];

        for (let i = 0, l = this.length; i < l; ++i) {
          const val = convertToNumber(this[i]);

          if (callback.call(thisArg, val, i, _(this).proxy)) {
            array.push(val);
          }
        }

        return new Float16Array(array);
      }

      reduce(callback) {
        assertFloat16Array(this);
        let val, start;

        if ((arguments.length <= 1 ? 0 : arguments.length - 1) === 0) {
          val = convertToNumber(this[0]);
          start = 1;
        } else {
          val = arguments.length <= 1 ? undefined : arguments[1];
          start = 0;
        }

        for (let i = start, l = this.length; i < l; ++i) {
          val = callback(val, convertToNumber(this[i]), i, _(this).proxy);
        }

        return val;
      }

      reduceRight(callback) {
        assertFloat16Array(this);
        let val, start;
        const length = this.length;

        if ((arguments.length <= 1 ? 0 : arguments.length - 1) === 0) {
          val = convertToNumber(this[length - 1]);
          start = length - 1;
        } else {
          val = arguments.length <= 1 ? undefined : arguments[1];
          start = length;
        }

        for (let i = start; i--;) {
          val = callback(val, convertToNumber(this[i]), i, _(this).proxy);
        }

        return val;
      }

      forEach(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];

        for (let i = 0, l = this.length; i < l; ++i) {
          callback.call(thisArg, convertToNumber(this[i]), i, _(this).proxy);
        }
      }

      find(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];

        for (let i = 0, l = this.length; i < l; ++i) {
          const value = convertToNumber(this[i]);
          if (callback.call(thisArg, value, i, _(this).proxy)) return value;
        }
      }

      findIndex(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];

        for (let i = 0, l = this.length; i < l; ++i) {
          const value = convertToNumber(this[i]);
          if (callback.call(thisArg, value, i, _(this).proxy)) return i;
        }

        return -1;
      }

      every(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];

        for (let i = 0, l = this.length; i < l; ++i) {
          if (!callback.call(thisArg, convertToNumber(this[i]), i, _(this).proxy)) return false;
        }

        return true;
      }

      some(callback) {
        assertFloat16Array(this);
        const thisArg = arguments.length <= 1 ? undefined : arguments[1];

        for (let i = 0, l = this.length; i < l; ++i) {
          if (callback.call(thisArg, convertToNumber(this[i]), i, _(this).proxy)) return true;
        }

        return false;
      } // change element methods


      set(input) {
        assertFloat16Array(this);
        const offset = arguments.length <= 1 ? undefined : arguments[1];
        let float16bits; // input Float16Array

        if (isFloat16Array(input)) {
          float16bits = _(input).target; // input others
        } else {
          const arrayLike = !Reflect.has(input, "length") && input[Symbol.iterator] !== undefined ? [...input] : input;
          const length = arrayLike.length;
          float16bits = new Uint16Array(length);

          for (let i = 0, l = arrayLike.length; i < l; ++i) {
            float16bits[i] = roundToFloat16Bits(arrayLike[i]);
          }
        }

        super.set(float16bits, offset);
      }

      reverse() {
        assertFloat16Array(this);
        super.reverse();
        return _(this).proxy;
      }

      fill(value) {
        assertFloat16Array(this);

        for (var _len3 = arguments.length, opts = new Array(_len3 > 1 ? _len3 - 1 : 0), _key3 = 1; _key3 < _len3; _key3++) {
          opts[_key3 - 1] = arguments[_key3];
        }

        super.fill(roundToFloat16Bits(value), ...opts);
        return _(this).proxy;
      }

      copyWithin(target, start) {
        assertFloat16Array(this);

        for (var _len4 = arguments.length, opts = new Array(_len4 > 2 ? _len4 - 2 : 0), _key4 = 2; _key4 < _len4; _key4++) {
          opts[_key4 - 2] = arguments[_key4];
        }

        super.copyWithin(target, start, ...opts);
        return _(this).proxy;
      }

      sort() {
        assertFloat16Array(this);
        let compareFunction = arguments.length <= 0 ? undefined : arguments[0];

        if (compareFunction === undefined) {
          compareFunction = defaultCompareFunction;
        }

        const _convertToNumber = memoize(convertToNumber);

        super.sort((x, y) => compareFunction(_convertToNumber(x), _convertToNumber(y)));
        return _(this).proxy;
      } // copy element methods


      slice() {
        assertFloat16Array(this);
        let float16bits; // V8, SpiderMonkey, JavaScriptCore, Chakra throw TypeError

        try {
          float16bits = super.slice(...arguments);
        } catch (e) {
          if (e instanceof TypeError) {
            const uint16 = new Uint16Array(this.buffer, this.byteOffset, this.length);
            float16bits = uint16.slice(...arguments);
          } else {
            throw e;
          }
        }

        return new Float16Array(float16bits.buffer);
      }

      subarray() {
        assertFloat16Array(this);
        let float16bits; // V8, SpiderMonkey, JavaScriptCore, Chakra throw TypeError

        try {
          float16bits = super.subarray(...arguments);
        } catch (e) {
          if (e instanceof TypeError) {
            const uint16 = new Uint16Array(this.buffer, this.byteOffset, this.length);
            float16bits = uint16.subarray(...arguments);
          } else {
            throw e;
          }
        }

        return new Float16Array(float16bits.buffer, float16bits.byteOffset, float16bits.length);
      } // contains methods


      indexOf(element) {
        assertFloat16Array(this);
        const length = this.length;
        let from = ToInteger(arguments.length <= 1 ? undefined : arguments[1]);

        if (from < 0) {
          from += length;
          if (from < 0) from = 0;
        }

        for (let i = from, l = length; i < l; ++i) {
          if (convertToNumber(this[i]) === element) return i;
        }

        return -1;
      }

      lastIndexOf(element) {
        assertFloat16Array(this);
        const length = this.length;
        let from = ToInteger(arguments.length <= 1 ? undefined : arguments[1]);
        from = from === 0 ? length : from + 1;

        if (from >= 0) {
          from = from < length ? from : length;
        } else {
          from += length;
        }

        for (let i = from; i--;) {
          if (convertToNumber(this[i]) === element) return i;
        }

        return -1;
      }

      includes(element) {
        assertFloat16Array(this);
        const length = this.length;
        let from = ToInteger(arguments.length <= 1 ? undefined : arguments[1]);

        if (from < 0) {
          from += length;
          if (from < 0) from = 0;
        }

        const isNaN = Number.isNaN(element);

        for (let i = from, l = length; i < l; ++i) {
          const value = convertToNumber(this[i]);
          if (isNaN && Number.isNaN(value)) return true;
          if (value === element) return true;
        }

        return false;
      } // string methods


      join() {
        assertFloat16Array(this);
        const array = copyToArray(this);
        return array.join(...arguments);
      }

      toLocaleString() {
        assertFloat16Array(this);
        const array = copyToArray(this);
        return array.toLocaleString(...arguments);
      }

      get [Symbol.toStringTag]() {
        if (isFloat16Array(this)) return "Float16Array";
      }

    }
    const Float16Array$prototype = Float16Array.prototype;
    const defaultFloat16ArrayMethods = new WeakSet();

    for (const key of Reflect.ownKeys(Float16Array$prototype)) {
      const val = Float16Array$prototype[key];
      if (typeof val === "function") defaultFloat16ArrayMethods.add(val);
    }

    /**
     * returns an unsigned 16-bit float at the specified byte offset from the start of the DataView.
     * @param {DataView} dataView
     * @param {nunmber} byteOffset
     * @param {*} opts
     */

    function getFloat16(dataView, byteOffset) {
      if (!isDataView(dataView)) throw new TypeError("First argument to getFloat16 function must be a DataView");

      for (var _len = arguments.length, opts = new Array(_len > 2 ? _len - 2 : 0), _key = 2; _key < _len; _key++) {
        opts[_key - 2] = arguments[_key];
      }

      return convertToNumber(dataView.getUint16(byteOffset, ...opts));
    }
    /**
     * stores an unsigned 16-bit float value at the specified byte offset from the start of the DataView.
     * @param {DataView} dataView
     * @param {number} byteOffset
     * @param {number} value
     * @param {*} opts
     */

    function setFloat16(dataView, byteOffset, value) {
      if (!isDataView(dataView)) throw new TypeError("First argument to setFloat16 function must be a DataView");

      for (var _len2 = arguments.length, opts = new Array(_len2 > 3 ? _len2 - 3 : 0), _key2 = 3; _key2 < _len2; _key2++) {
        opts[_key2 - 3] = arguments[_key2];
      }

      dataView.setUint16(byteOffset, roundToFloat16Bits(value), ...opts);
    }

    exports.Float16Array = Float16Array;
    exports.getFloat16 = getFloat16;
    exports.hfround = hfround;
    exports.setFloat16 = setFloat16;

    return exports;

}({}));


================================================
FILE: index.html
================================================
<meta charset="utf8">
<title>Float Toy</title>
<style>
  body {
    margin: 50px;
    font: 14px/20px sans-serif;
    cursor: default;
  }

  a {
    color: inherit;
  }

  p {
    margin: 30px 0;
  }

  h2 {
    margin: 60px 0 30px 0;
  }

  table {
    border-collapse: collapse;
    font-size: 20px;
    line-height: 14px;
    width: 100%;
  }

  td {
    font: inherit;
    padding: 0;
    text-align: center;
  }

  td.sign { background: #BBF; }
  td.exponent { background: #BFB; }
  td.fraction { background: #FBB; }

  td.sign.hover { background: #99D; }
  td.exponent.hover { background: #9D9; }
  td.fraction.hover { background: #D99; }

  .input td {
    border: 1px solid #000;
    padding: 5px 2px;
    font-size: 14px;
  }

  .zerox-col {
    vertical-align: bottom;
  }

  .zerox {
    height: 26px;
    line-height: 26px;
  }

  .output-col {
    width: 100%;
    vertical-align: bottom;
  }

  .hex-col {
    width: 100%;
  }

  .output {
    font: inherit;
    padding: 5px;
    margin: -5px;
    border: 0;
    outline: none;
    width: 100%;
    min-width: 200px;
    background: none;
    height: 26px;
    line-height: 26px;
    box-sizing: content-box;
  }

  .output:hover, .output:focus {
    background: rgba(0, 0, 0, 0.066);
  }

  .help {
    height: 50px;
    font-size: 20px;
    line-height: 60px;
    padding-left: 3px;
    white-space: nowrap;
  }

  .help sup {
    vertical-align: top;
    font-size: 12px;
    line-height: 50px;
  }

  .help span {
    padding: 3px;
    margin: -3px;
  }

  td.nibble {
    font-size: 10px;
    line-height: 6px;
    border: none;
  }

  td.dark.nibble {
    background: #DDD;
  }

  span.sign { background: #DDF; }
  span.exponent { background: #DFD; }
  span.fraction { background: #FDD; }

</style>
<body>
  <h1>Float Toy</h1>
  <p>
    Click on a cell below to toggle bit values, or edit the hex or decimal values directly.
    Use this to build intuition for the IEEE floating-point format.
    See Wikipedia for details on the <a href="https://en.wikipedia.org/wiki/Half-precision_floating-point_format">half-precision</a>, <a href="https://en.wikipedia.org/wiki/Single-precision_floating-point_format">single-precision</a> and <a href="https://en.wikipedia.org/wiki/Double-precision_floating-point_format">double-precision</a> floating-point formats.
  </p>

  <h2>16-bit (half)</h2>
  <table>
    <tr>
      <td><span id="input16" class="input"></span></td>
      <td class="zerox-col"><span class="zerox">&nbsp;&nbsp;=&nbsp;&nbsp;0x</span></td>
      <td class="output-col"><input id="hex16" class="output"></td>
    </tr>
  </table>
  <table>
    <tr>
      <td><span id="help16" class="help"></span></td>
      <td>&nbsp;&nbsp;=&nbsp;&nbsp;</td>
      <td class="hex-col"><input id="output16" class="output"></td>
    </tr>
  </table>

  <h2>32-bit (float)</h2>
  <table>
    <tr>
      <td><span id="input32" class="input"></span></td>
      <td class="zerox-col"><span class="zerox">&nbsp;&nbsp;=&nbsp;&nbsp;0x</span></td>
      <td class="output-col"><input id="hex32" class="output"></td>
    </tr>
  </table>
  <table>
    <tr>
      <td><span id="help32" class="help"></span></td>
      <td>&nbsp;&nbsp;=&nbsp;&nbsp;</td>
      <td class="hex-col"><input id="output32" class="output"></td>
    </tr>
  </table>

  <h2>64-bit (double)</h2>
  <table>
    <tr>
      <td><span id="input64" class="input"></span></td>
      <td class="zerox-col"><span class="zerox">&nbsp;&nbsp;=&nbsp;&nbsp;0x</span></td>
      <td class="output-col"><input id="hex64" class="output"></td>
    </tr>
  </table>
  <table>
    <tr>
      <td><span id="help64" class="help"></span></td>
      <td>&nbsp;&nbsp;=&nbsp;&nbsp;</td>
      <td class="hex-col"><input id="output64" class="output"></td>
    </tr>
  </table>
</body>
<script src="./float16.js"></script>
<script>
const {Float16Array} = float16;

(function () {

  function load(array, exponentBits, input, output, help, hex) {
    var bytes = new Uint8Array(array.buffer);
    var hexLength = bytes.length;

    function reduceNumber(x) {
      var copy = bytes.length === 2 ? new Float16Array(1) : bytes.length === 4 ? new Float32Array(1) : new Float64Array(1);
      copy[0] = +x;
      var value = copy[0];
      x = value === 0 && 1 / value === -Infinity ? '-0' : value + '';

      if (x === 'NaN' || x === 'Infinity' || x === '-Infinity') {
        return x;
      }

      var parts = /^([+-]?\d+)((?:\.\d+)?)((?:[eE][+-]?\d+)?)$/.exec(x);
      var whole = parts[1];
      var fraction = parts[2];
      var exponent = parts[3];

      // Remove digits one-by-one until the number changes
      while (fraction.length > 0) {
        // Try truncating
        var truncatedFraction = fraction.slice(0, -1);
        var text = whole + (truncatedFraction !== '.' ? truncatedFraction : '') + exponent;
        copy[0] = +text;
        var truncatedValue = copy[0];
        if (truncatedValue === value) {
          fraction = truncatedFraction;
          x = text;
          continue;
        }

        // Try rounding
        var roundedFraction = truncatedFraction;
        var i = roundedFraction.length - 1;
        var zero = '0'.charCodeAt(0);
        while (i > 0) {
          var c = roundedFraction.charCodeAt(i) - zero;
          roundedFraction = roundedFraction.slice(0, i) + String.fromCharCode((c + 1) % 10 + zero) + roundedFraction.slice(i + 1);
          if (c < 9) break; // Do we need to carry?
          i--;
        }
        var text = whole + (roundedFraction !== '.' ? roundedFraction : '') + exponent;
        copy[0] = +text;
        var roundedValue = copy[0];
        if (roundedValue === value) {
          fraction = roundedFraction;
          x = text;
          continue;
        }

        // Both numbers changed, keep the old value
        break;
      }

      return x;
    }

    // Populate HTML
    var html = '<table>';
    // The bit numbers
    html += '<tr>';
    for (var i = 0; i < bytes.length; i++) {
      for (var j = 0; j < 8; j++) {
        var index = (bytes.length - i) * 8 - j;
        if (j > 3) {
          html += '<td class="nibble">' + index + '</td>'
        } else {
          html += '<td class="dark nibble">' + index + '</td>'
        }
      }
    }
    html += '</tr>';
    // The bits
    html += '<tr>';
    for (var i = 0; i < bytes.length; i++) {
      for (var j = 0; j < 8; j++) {
        var index = i * 8 + j;
        var className =
          index === 0 ? 'sign' :
            index < 1 + exponentBits ? 'exponent' :
              'fraction';
        html += '<td data-index="' + index + '" class="' + className + '">0</td>';
      }
    }
    html += '</tr></table>';
    input.innerHTML = html;

    // Grab elements
    var elements = [];
    for (var i = 0; i < bytes.length * 8; i++) {
      (function (i) {
        var element = input.querySelector('[data-index="' + i + '"]');
        element.onmouseover = function () { this.classList.add('hover'); };
        element.onmouseout = function () { this.classList.remove('hover'); };
        elements.push(element);
      })(i);
    }

    // Event handlers
    function extractNumber() {
      return +(output.value.replace(/\b(?:infinity|inf)\b/gi, 'Infinity'));
    }
    output.onkeydown = function (e) {
      if (e.which === 13) {
        e.preventDefault();
        output.blur();
      }

      else if (e.which === 38) {
        e.preventDefault();
        output.value = reduceNumber(extractNumber() + 1);
        output.select();
        output.oninput();
      }

      else if (e.which === 40) {
        e.preventDefault();
        output.value = reduceNumber(extractNumber() - 1);
        output.select();
        output.oninput();
      }
    };
    output.onfocus = function () {
      output.select();
    };
    output.oninput = function () {
      array[0] = extractNumber();
      render();
    };
    output.onblur = function () {
      render();
    };

    hex.onkeydown = function (e) {
      if (e.which === 13) {
        e.preventDefault();
        hex.blur();
      }
    };
    hex.onfocus = function () {
      hex.select();
    };
    hex.oninput = function () {
      var hexAlphabet = '0123456789abcdefABCDEF';
      var validHexCharas = hex.value.split('').every(function (c) {
        return hexAlphabet.split('').lastIndexOf(c) !== -1;
      });
      if (hex.value.length > (hexLength * 2) || validHexCharas === false) {
        hex.value = hex.value.slice(0, -1);
        return;
      }

      var tmpBytes = toByteArray(hex.value);
      bytes.fill(0);
      bytes.set(tmpBytes.reverse(), hexLength - tmpBytes.length);
      render();
    };
    hex.onblur = function () {
      render();
    };

    input.onmousedown = function (e) {
      if ('index' in e.target.dataset) {
        var index = e.target.dataset.index | 0;
        var byteIndex = bytes.length - (index >> 3) - 1;
        var byteMask = 1 << (7 - (index & 7));
        var mouseDownValue = bytes[byteIndex] & byteMask ? 0 : 1;
        bytes[byteIndex] ^= byteMask;
        render();

        document.onmousemove = function (e2) {
          if ('index' in e2.target.dataset) {
            var index = e2.target.dataset.index | 0;
            var byteIndex = bytes.length - (index >> 3) - 1;
            var byteMask = 1 << (7 - (index & 7));
            bytes[byteIndex] = (bytes[byteIndex] & ~byteMask) | (byteMask * mouseDownValue);
            render();
          }
        };

        document.onmouseup = function () {
          document.onmousemove = null;
          document.onmouseup = null;
        };
      }
    };

    // Update loop
    function render() {
      for (var i = 0; i < bytes.length * 8; i++) {
        elements[i].textContent = ((bytes[bytes.length - (i >> 3) - 1] >> (7 - (i & 7))) & 1);
      }

      // Figure out exponent
      var exponent = 0;
      for (var i = 0; i < exponentBits; i++) {
        var index = 1 + i;
        var bit = (bytes[bytes.length - (index >> 3) - 1] >> (7 - (index & 7))) & 1;
        exponent += bit << (exponentBits - i - 1);
      }
      var exponentBias = (1 << (exponentBits - 1)) - 1;
      exponent -= exponentBias;

      // Figure out fraction
      var copyBytes = new Uint8Array(bytes);
      var copy = bytes.length === 2 ? new Float16Array(copyBytes.buffer) : bytes.length === 4 ? new Float32Array(copyBytes.buffer) : new Float64Array(copyBytes.buffer);
      for (var i = 0; i < exponentBits; i++) {
        var index = 1 + i;
        var byteIndex = bytes.length - (index >> 3) - 1;
        var byteMask = 1 << (7 - (index & 7));
        copyBytes[byteIndex] = (copyBytes[byteIndex] & ~byteMask) | (i === 0 ? 0 : byteMask);
      }
      var signIndex = bytes.length - 1;
      var signMask = 0x80;
      var sign = copyBytes[signIndex] & signMask;
      copyBytes[signIndex] &= ~signMask;
      var fraction = copy[0];

      // Handle denormal numbers
      if (exponent === -exponentBias) {
        exponent++;
        fraction--;
      }

      // Update views according to which input was edited
      if (document.activeElement === hex) {
        var value = array[0];
        output.value = reduceNumber(value === 0 && 1 / value === -Infinity ? '-0' : value);
      } else if (document.activeElement === output) {
        var tmpBytes = bytes.slice().reverse();
        hex.value = toHexString(tmpBytes);
      } else { // This branch is for when the individual bits get toggled
        var value = array[0];
        output.value = reduceNumber(value === 0 && 1 / value === -Infinity ? '-0' : value);
        var tmpBytes = bytes.slice().reverse();
        hex.value = toHexString(tmpBytes);
      }

      help.innerHTML =
        '<span class="sign">' + (sign ? -1 : 1) + '</span>' +
        '&nbsp;&nbsp;&times;&nbsp;&nbsp;' +
        '<span class="exponent">2<sup>' + exponent + '</sup></span>' +
        '&nbsp;&nbsp;&times;&nbsp;&nbsp;' +
        '<span class="fraction">' + reduceNumber(fraction) + '</span>';
    }

    function toHexString(byteArray) {
      return Array.from(byteArray, function (byte) {
        return ('0' + byte.toString(16).toUpperCase()).slice(-2);
      }).join('')
    }

    function toByteArray(hexString) {
      var result = [];
      if (hexString.length % 2 == 1) {
        hexString = hexString + '0';
      }
      for (var i = 0; i < hexString.length; i += 2) {
        result.push(parseInt(hexString.substr(i, 2), 16));
      }
      return result;
    }

    render();
  }

  load(new Float16Array([Math.PI]), 5, document.getElementById('input16'), document.getElementById('output16'), document.getElementById('help16'), document.getElementById('hex16'));
  load(new Float32Array([Math.PI]), 8, document.getElementById('input32'), document.getElementById('output32'), document.getElementById('help32'), document.getElementById('hex32'));
  load(new Float64Array([Math.PI]), 11, document.getElementById('input64'), document.getElementById('output64'), document.getElementById('help64'), document.getElementById('hex64'));

})();

</script>