@okwallet/extension/dist/index.min.js

OKX Wallet provides official SDK packages of multiple chains including [Ethereum](./wallet), [Aptos](./aptos-api), [Tron](./tron-api) and Solana. Developers can interact with different on-chain projects through OKX Wallet SDK.

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 * It uses "eval()" calls to create a separate source file in the browser devtools.
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 * or disable the default devtool with "devtool: false".
 * If you are looking for production-ready output files, see mode: "production" (https://webpack.js.org/configuration/mode/).
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/***/ "./node_modules/_@solana_buffer-layout@4.0.1@@solana/buffer-layout/lib/Layout.js":
/*!***************************************************************************************!*\
  !*** ./node_modules/_@solana_buffer-layout@4.0.1@@solana/buffer-layout/lib/Layout.js ***!
  \***************************************************************************************/
/***/ (function(__unused_webpack_module, exports, __webpack_require__) {

"use strict";
eval("/* The MIT License (MIT)\n *\n * Copyright 2015-2018 Peter A. Bigot\n *\n * Permission is hereby granted, free of charge, to any person obtaining a copy\n * of this software and associated documentation files (the \"Software\"), to deal\n * in the Software without restriction, including without limitation the rights\n * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n * copies of the Software, and to permit persons to whom the Software is\n * furnished to do so, subject to the following conditions:\n *\n * The above copyright notice and this permission notice shall be included in\n * all copies or substantial portions of the Software.\n *\n * THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN\n * THE SOFTWARE.\n */\n/**\n * Support for translating between Uint8Array instances and JavaScript\n * native types.\n *\n * {@link module:Layout~Layout|Layout} is the basis of a class\n * hierarchy that associates property names with sequences of encoded\n * bytes.\n *\n * Layouts are supported for these scalar (numeric) types:\n * * {@link module:Layout~UInt|Unsigned integers in little-endian\n *   format} with {@link module:Layout.u8|8-bit}, {@link\n *   module:Layout.u16|16-bit}, {@link module:Layout.u24|24-bit},\n *   {@link module:Layout.u32|32-bit}, {@link\n *   module:Layout.u40|40-bit}, and {@link module:Layout.u48|48-bit}\n *   representation ranges;\n * * {@link module:Layout~UIntBE|Unsigned integers in big-endian\n *   format} with {@link module:Layout.u16be|16-bit}, {@link\n *   module:Layout.u24be|24-bit}, {@link module:Layout.u32be|32-bit},\n *   {@link module:Layout.u40be|40-bit}, and {@link\n *   module:Layout.u48be|48-bit} representation ranges;\n * * {@link module:Layout~Int|Signed integers in little-endian\n *   format} with {@link module:Layout.s8|8-bit}, {@link\n *   module:Layout.s16|16-bit}, {@link module:Layout.s24|24-bit},\n *   {@link module:Layout.s32|32-bit}, {@link\n *   module:Layout.s40|40-bit}, and {@link module:Layout.s48|48-bit}\n *   representation ranges;\n * * {@link module:Layout~IntBE|Signed integers in big-endian format}\n *   with {@link module:Layout.s16be|16-bit}, {@link\n *   module:Layout.s24be|24-bit}, {@link module:Layout.s32be|32-bit},\n *   {@link module:Layout.s40be|40-bit}, and {@link\n *   module:Layout.s48be|48-bit} representation ranges;\n * * 64-bit integral values that decode to an exact (if magnitude is\n *   less than 2^53) or nearby integral Number in {@link\n *   module:Layout.nu64|unsigned little-endian}, {@link\n *   module:Layout.nu64be|unsigned big-endian}, {@link\n *   module:Layout.ns64|signed little-endian}, and {@link\n *   module:Layout.ns64be|unsigned big-endian} encodings;\n * * 32-bit floating point values with {@link\n *   module:Layout.f32|little-endian} and {@link\n *   module:Layout.f32be|big-endian} representations;\n * * 64-bit floating point values with {@link\n *   module:Layout.f64|little-endian} and {@link\n *   module:Layout.f64be|big-endian} representations;\n * * {@link module:Layout.const|Constants} that take no space in the\n *   encoded expression.\n *\n * and for these aggregate types:\n * * {@link module:Layout.seq|Sequence}s of instances of a {@link\n *   module:Layout~Layout|Layout}, with JavaScript representation as\n *   an Array and constant or data-dependent {@link\n *   module:Layout~Sequence#count|length};\n * * {@link module:Layout.struct|Structure}s that aggregate a\n *   heterogeneous sequence of {@link module:Layout~Layout|Layout}\n *   instances, with JavaScript representation as an Object;\n * * {@link module:Layout.union|Union}s that support multiple {@link\n *   module:Layout~VariantLayout|variant layouts} over a fixed\n *   (padded) or variable (not padded) span of bytes, using an\n *   unsigned integer at the start of the data or a separate {@link\n *   module:Layout.unionLayoutDiscriminator|layout element} to\n *   determine which layout to use when interpreting the buffer\n *   contents;\n * * {@link module:Layout.bits|BitStructure}s that contain a sequence\n *   of individual {@link\n *   module:Layout~BitStructure#addField|BitField}s packed into an 8,\n *   16, 24, or 32-bit unsigned integer starting at the least- or\n *   most-significant bit;\n * * {@link module:Layout.cstr|C strings} of varying length;\n * * {@link module:Layout.blob|Blobs} of fixed- or variable-{@link\n *   module:Layout~Blob#length|length} raw data.\n *\n * All {@link module:Layout~Layout|Layout} instances are immutable\n * after construction, to prevent internal state from becoming\n * inconsistent.\n *\n * @local Layout\n * @local ExternalLayout\n * @local GreedyCount\n * @local OffsetLayout\n * @local UInt\n * @local UIntBE\n * @local Int\n * @local IntBE\n * @local NearUInt64\n * @local NearUInt64BE\n * @local NearInt64\n * @local NearInt64BE\n * @local Float\n * @local FloatBE\n * @local Double\n * @local DoubleBE\n * @local Sequence\n * @local Structure\n * @local UnionDiscriminator\n * @local UnionLayoutDiscriminator\n * @local Union\n * @local VariantLayout\n * @local BitStructure\n * @local BitField\n * @local Boolean\n * @local Blob\n * @local CString\n * @local Constant\n * @local bindConstructorLayout\n * @module Layout\n * @license MIT\n * @author Peter A. Bigot\n * @see {@link https://github.com/pabigot/buffer-layout|buffer-layout on GitHub}\n */\n\n\nObject.defineProperty(exports, \"__esModule\", ({\n  value: true\n}));\nexports.s16 = exports.s8 = exports.nu64be = exports.u48be = exports.u40be = exports.u32be = exports.u24be = exports.u16be = exports.nu64 = exports.u48 = exports.u40 = exports.u32 = exports.u24 = exports.u16 = exports.u8 = exports.offset = exports.greedy = exports.Constant = exports.UTF8 = exports.CString = exports.Blob = exports.Boolean = exports.BitField = exports.BitStructure = exports.VariantLayout = exports.Union = exports.UnionLayoutDiscriminator = exports.UnionDiscriminator = exports.Structure = exports.Sequence = exports.DoubleBE = exports.Double = exports.FloatBE = exports.Float = exports.NearInt64BE = exports.NearInt64 = exports.NearUInt64BE = exports.NearUInt64 = exports.IntBE = exports.Int = exports.UIntBE = exports.UInt = exports.OffsetLayout = exports.GreedyCount = exports.ExternalLayout = exports.bindConstructorLayout = exports.nameWithProperty = exports.Layout = exports.uint8ArrayToBuffer = exports.checkUint8Array = void 0;\nexports.constant = exports.utf8 = exports.cstr = exports.blob = exports.unionLayoutDiscriminator = exports.union = exports.seq = exports.bits = exports.struct = exports.f64be = exports.f64 = exports.f32be = exports.f32 = exports.ns64be = exports.s48be = exports.s40be = exports.s32be = exports.s24be = exports.s16be = exports.ns64 = exports.s48 = exports.s40 = exports.s32 = exports.s24 = void 0;\nconst buffer_1 = __webpack_require__(/*! buffer */ \"./node_modules/_buffer@6.0.3@buffer/index.js\");\n/* Check if a value is a Uint8Array.\n *\n * @ignore */\nfunction checkUint8Array(b) {\n  if (!(b instanceof Uint8Array)) {\n    throw new TypeError('b must be a Uint8Array');\n  }\n}\nexports.checkUint8Array = checkUint8Array;\n/* Create a Buffer instance from a Uint8Array.\n *\n * @ignore */\nfunction uint8ArrayToBuffer(b) {\n  checkUint8Array(b);\n  return buffer_1.Buffer.from(b.buffer, b.byteOffset, b.length);\n}\nexports.uint8ArrayToBuffer = uint8ArrayToBuffer;\n/**\n * Base class for layout objects.\n *\n * **NOTE** This is an abstract base class; you can create instances\n * if it amuses you, but they won't support the {@link\n * Layout#encode|encode} or {@link Layout#decode|decode} functions.\n *\n * @param {Number} span - Initializer for {@link Layout#span|span}.  The\n * parameter must be an integer; a negative value signifies that the\n * span is {@link Layout#getSpan|value-specific}.\n *\n * @param {string} [property] - Initializer for {@link\n * Layout#property|property}.\n *\n * @abstract\n */\nclass Layout {\n  constructor(span, property) {\n    if (!Number.isInteger(span)) {\n      throw new TypeError('span must be an integer');\n    }\n    /** The span of the layout in bytes.\n     *\n     * Positive values are generally expected.\n     *\n     * Zero will only appear in {@link Constant}s and in {@link\n     * Sequence}s where the {@link Sequence#count|count} is zero.\n     *\n     * A negative value indicates that the span is value-specific, and\n     * must be obtained using {@link Layout#getSpan|getSpan}. */\n    this.span = span;\n    /** The property name used when this layout is represented in an\n     * Object.\n     *\n     * Used only for layouts that {@link Layout#decode|decode} to Object\n     * instances.  If left undefined the span of the unnamed layout will\n     * be treated as padding: it will not be mutated by {@link\n     * Layout#encode|encode} nor represented as a property in the\n     * decoded Object. */\n    this.property = property;\n  }\n  /** Function to create an Object into which decoded properties will\n   * be written.\n   *\n   * Used only for layouts that {@link Layout#decode|decode} to Object\n   * instances, which means:\n   * * {@link Structure}\n   * * {@link Union}\n   * * {@link VariantLayout}\n   * * {@link BitStructure}\n   *\n   * If left undefined the JavaScript representation of these layouts\n   * will be Object instances.\n   *\n   * See {@link bindConstructorLayout}.\n   */\n  makeDestinationObject() {\n    return {};\n  }\n  /**\n   * Calculate the span of a specific instance of a layout.\n   *\n   * @param {Uint8Array} b - the buffer that contains an encoded instance.\n   *\n   * @param {Number} [offset] - the offset at which the encoded instance\n   * starts.  If absent a zero offset is inferred.\n   *\n   * @return {Number} - the number of bytes covered by the layout\n   * instance.  If this method is not overridden in a subclass the\n   * definition-time constant {@link Layout#span|span} will be\n   * returned.\n   *\n   * @throws {RangeError} - if the length of the value cannot be\n   * determined.\n   */\n  getSpan(b, offset) {\n    if (0 > this.span) {\n      throw new RangeError('indeterminate span');\n    }\n    return this.span;\n  }\n  /**\n   * Replicate the layout using a new property.\n   *\n   * This function must be used to get a structurally-equivalent layout\n   * with a different name since all {@link Layout} instances are\n   * immutable.\n   *\n   * **NOTE** This is a shallow copy.  All fields except {@link\n   * Layout#property|property} are strictly equal to the origin layout.\n   *\n   * @param {String} property - the value for {@link\n   * Layout#property|property} in the replica.\n   *\n   * @returns {Layout} - the copy with {@link Layout#property|property}\n   * set to `property`.\n   */\n  replicate(property) {\n    const rv = Object.create(this.constructor.prototype);\n    Object.assign(rv, this);\n    rv.property = property;\n    return rv;\n  }\n  /**\n   * Create an object from layout properties and an array of values.\n   *\n   * **NOTE** This function returns `undefined` if invoked on a layout\n   * that does not return its value as an Object.  Objects are\n   * returned for things that are a {@link Structure}, which includes\n   * {@link VariantLayout|variant layouts} if they are structures, and\n   * excludes {@link Union}s.  If you want this feature for a union\n   * you must use {@link Union.getVariant|getVariant} to select the\n   * desired layout.\n   *\n   * @param {Array} values - an array of values that correspond to the\n   * default order for properties.  As with {@link Layout#decode|decode}\n   * layout elements that have no property name are skipped when\n   * iterating over the array values.  Only the top-level properties are\n   * assigned; arguments are not assigned to properties of contained\n   * layouts.  Any unused values are ignored.\n   *\n   * @return {(Object|undefined)}\n   */\n  fromArray(values) {\n    return undefined;\n  }\n}\nexports.Layout = Layout;\n/* Provide text that carries a name (such as for a function that will\n * be throwing an error) annotated with the property of a given layout\n * (such as one for which the value was unacceptable).\n *\n * @ignore */\nfunction nameWithProperty(name, lo) {\n  if (lo.property) {\n    return name + '[' + lo.property + ']';\n  }\n  return name;\n}\nexports.nameWithProperty = nameWithProperty;\n/**\n * Augment a class so that instances can be encoded/decoded using a\n * given layout.\n *\n * Calling this function couples `Class` with `layout` in several ways:\n *\n * * `Class.layout_` becomes a static member property equal to `layout`;\n * * `layout.boundConstructor_` becomes a static member property equal\n *    to `Class`;\n * * The {@link Layout#makeDestinationObject|makeDestinationObject()}\n *   property of `layout` is set to a function that returns a `new\n *   Class()`;\n * * `Class.decode(b, offset)` becomes a static member function that\n *   delegates to {@link Layout#decode|layout.decode}.  The\n *   synthesized function may be captured and extended.\n * * `Class.prototype.encode(b, offset)` provides an instance member\n *   function that delegates to {@link Layout#encode|layout.encode}\n *   with `src` set to `this`.  The synthesized function may be\n *   captured and extended, but when the extension is invoked `this`\n *   must be explicitly bound to the instance.\n *\n * @param {class} Class - a JavaScript class with a nullary\n * constructor.\n *\n * @param {Layout} layout - the {@link Layout} instance used to encode\n * instances of `Class`.\n */\n// `Class` must be a constructor Function, but the assignment of a `layout_` property to it makes it difficult to type\n// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types\nfunction bindConstructorLayout(Class, layout) {\n  if ('function' !== typeof Class) {\n    throw new TypeError('Class must be constructor');\n  }\n  if (Object.prototype.hasOwnProperty.call(Class, 'layout_')) {\n    throw new Error('Class is already bound to a layout');\n  }\n  if (!(layout && layout instanceof Layout)) {\n    throw new TypeError('layout must be a Layout');\n  }\n  if (Object.prototype.hasOwnProperty.call(layout, 'boundConstructor_')) {\n    throw new Error('layout is already bound to a constructor');\n  }\n  Class.layout_ = layout;\n  layout.boundConstructor_ = Class;\n  layout.makeDestinationObject = () => new Class();\n  Object.defineProperty(Class.prototype, 'encode', {\n    value(b, offset) {\n      return layout.encode(this, b, offset);\n    },\n    writable: true\n  });\n  Object.defineProperty(Class, 'decode', {\n    value(b, offset) {\n      return layout.decode(b, offset);\n    },\n    writable: true\n  });\n}\nexports.bindConstructorLayout = bindConstructorLayout;\n/**\n * An object that behaves like a layout but does not consume space\n * within its containing layout.\n *\n * This is primarily used to obtain metadata about a member, such as a\n * {@link OffsetLayout} that can provide data about a {@link\n * Layout#getSpan|value-specific span}.\n *\n * **NOTE** This is an abstract base class; you can create instances\n * if it amuses you, but they won't support {@link\n * ExternalLayout#isCount|isCount} or other {@link Layout} functions.\n *\n * @param {Number} span - initializer for {@link Layout#span|span}.\n * The parameter can range from 1 through 6.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @abstract\n * @augments {Layout}\n */\nclass ExternalLayout extends Layout {\n  /**\n   * Return `true` iff the external layout decodes to an unsigned\n   * integer layout.\n   *\n   * In that case it can be used as the source of {@link\n   * Sequence#count|Sequence counts}, {@link Blob#length|Blob lengths},\n   * or as {@link UnionLayoutDiscriminator#layout|external union\n   * discriminators}.\n   *\n   * @abstract\n   */\n  isCount() {\n    throw new Error('ExternalLayout is abstract');\n  }\n}\nexports.ExternalLayout = ExternalLayout;\n/**\n * An {@link ExternalLayout} that determines its {@link\n * Layout#decode|value} based on offset into and length of the buffer\n * on which it is invoked.\n *\n * *Factory*: {@link module:Layout.greedy|greedy}\n *\n * @param {Number} [elementSpan] - initializer for {@link\n * GreedyCount#elementSpan|elementSpan}.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {ExternalLayout}\n */\nclass GreedyCount extends ExternalLayout {\n  constructor(elementSpan = 1, property) {\n    if (!Number.isInteger(elementSpan) || 0 >= elementSpan) {\n      throw new TypeError('elementSpan must be a (positive) integer');\n    }\n    super(-1, property);\n    /** The layout for individual elements of the sequence.  The value\n     * must be a positive integer.  If not provided, the value will be\n     * 1. */\n    this.elementSpan = elementSpan;\n  }\n  /** @override */\n  isCount() {\n    return true;\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    checkUint8Array(b);\n    const rem = b.length - offset;\n    return Math.floor(rem / this.elementSpan);\n  }\n  /** @override */\n  encode(src, b, offset) {\n    return 0;\n  }\n}\nexports.GreedyCount = GreedyCount;\n/**\n * An {@link ExternalLayout} that supports accessing a {@link Layout}\n * at a fixed offset from the start of another Layout.  The offset may\n * be before, within, or after the base layout.\n *\n * *Factory*: {@link module:Layout.offset|offset}\n *\n * @param {Layout} layout - initializer for {@link\n * OffsetLayout#layout|layout}, modulo `property`.\n *\n * @param {Number} [offset] - Initializes {@link\n * OffsetLayout#offset|offset}.  Defaults to zero.\n *\n * @param {string} [property] - Optional new property name for a\n * {@link Layout#replicate| replica} of `layout` to be used as {@link\n * OffsetLayout#layout|layout}.  If not provided the `layout` is used\n * unchanged.\n *\n * @augments {Layout}\n */\nclass OffsetLayout extends ExternalLayout {\n  constructor(layout, offset = 0, property) {\n    if (!(layout instanceof Layout)) {\n      throw new TypeError('layout must be a Layout');\n    }\n    if (!Number.isInteger(offset)) {\n      throw new TypeError('offset must be integer or undefined');\n    }\n    super(layout.span, property || layout.property);\n    /** The subordinated layout. */\n    this.layout = layout;\n    /** The location of {@link OffsetLayout#layout} relative to the\n     * start of another layout.\n     *\n     * The value may be positive or negative, but an error will thrown\n     * if at the point of use it goes outside the span of the Uint8Array\n     * being accessed.  */\n    this.offset = offset;\n  }\n  /** @override */\n  isCount() {\n    return this.layout instanceof UInt || this.layout instanceof UIntBE;\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return this.layout.decode(b, offset + this.offset);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    return this.layout.encode(src, b, offset + this.offset);\n  }\n}\nexports.OffsetLayout = OffsetLayout;\n/**\n * Represent an unsigned integer in little-endian format.\n *\n * *Factory*: {@link module:Layout.u8|u8}, {@link\n *  module:Layout.u16|u16}, {@link module:Layout.u24|u24}, {@link\n *  module:Layout.u32|u32}, {@link module:Layout.u40|u40}, {@link\n *  module:Layout.u48|u48}\n *\n * @param {Number} span - initializer for {@link Layout#span|span}.\n * The parameter can range from 1 through 6.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass UInt extends Layout {\n  constructor(span, property) {\n    super(span, property);\n    if (6 < this.span) {\n      throw new RangeError('span must not exceed 6 bytes');\n    }\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readUIntLE(offset, this.span);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeUIntLE(src, offset, this.span);\n    return this.span;\n  }\n}\nexports.UInt = UInt;\n/**\n * Represent an unsigned integer in big-endian format.\n *\n * *Factory*: {@link module:Layout.u8be|u8be}, {@link\n * module:Layout.u16be|u16be}, {@link module:Layout.u24be|u24be},\n * {@link module:Layout.u32be|u32be}, {@link\n * module:Layout.u40be|u40be}, {@link module:Layout.u48be|u48be}\n *\n * @param {Number} span - initializer for {@link Layout#span|span}.\n * The parameter can range from 1 through 6.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass UIntBE extends Layout {\n  constructor(span, property) {\n    super(span, property);\n    if (6 < this.span) {\n      throw new RangeError('span must not exceed 6 bytes');\n    }\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readUIntBE(offset, this.span);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeUIntBE(src, offset, this.span);\n    return this.span;\n  }\n}\nexports.UIntBE = UIntBE;\n/**\n * Represent a signed integer in little-endian format.\n *\n * *Factory*: {@link module:Layout.s8|s8}, {@link\n *  module:Layout.s16|s16}, {@link module:Layout.s24|s24}, {@link\n *  module:Layout.s32|s32}, {@link module:Layout.s40|s40}, {@link\n *  module:Layout.s48|s48}\n *\n * @param {Number} span - initializer for {@link Layout#span|span}.\n * The parameter can range from 1 through 6.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass Int extends Layout {\n  constructor(span, property) {\n    super(span, property);\n    if (6 < this.span) {\n      throw new RangeError('span must not exceed 6 bytes');\n    }\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readIntLE(offset, this.span);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeIntLE(src, offset, this.span);\n    return this.span;\n  }\n}\nexports.Int = Int;\n/**\n * Represent a signed integer in big-endian format.\n *\n * *Factory*: {@link module:Layout.s8be|s8be}, {@link\n * module:Layout.s16be|s16be}, {@link module:Layout.s24be|s24be},\n * {@link module:Layout.s32be|s32be}, {@link\n * module:Layout.s40be|s40be}, {@link module:Layout.s48be|s48be}\n *\n * @param {Number} span - initializer for {@link Layout#span|span}.\n * The parameter can range from 1 through 6.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass IntBE extends Layout {\n  constructor(span, property) {\n    super(span, property);\n    if (6 < this.span) {\n      throw new RangeError('span must not exceed 6 bytes');\n    }\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readIntBE(offset, this.span);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeIntBE(src, offset, this.span);\n    return this.span;\n  }\n}\nexports.IntBE = IntBE;\nconst V2E32 = Math.pow(2, 32);\n/* True modulus high and low 32-bit words, where low word is always\n * non-negative. */\nfunction divmodInt64(src) {\n  const hi32 = Math.floor(src / V2E32);\n  const lo32 = src - hi32 * V2E32;\n  return {\n    hi32,\n    lo32\n  };\n}\n/* Reconstruct Number from quotient and non-negative remainder */\nfunction roundedInt64(hi32, lo32) {\n  return hi32 * V2E32 + lo32;\n}\n/**\n * Represent an unsigned 64-bit integer in little-endian format when\n * encoded and as a near integral JavaScript Number when decoded.\n *\n * *Factory*: {@link module:Layout.nu64|nu64}\n *\n * **NOTE** Values with magnitude greater than 2^52 may not decode to\n * the exact value of the encoded representation.\n *\n * @augments {Layout}\n */\nclass NearUInt64 extends Layout {\n  constructor(property) {\n    super(8, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    const buffer = uint8ArrayToBuffer(b);\n    const lo32 = buffer.readUInt32LE(offset);\n    const hi32 = buffer.readUInt32LE(offset + 4);\n    return roundedInt64(hi32, lo32);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    const split = divmodInt64(src);\n    const buffer = uint8ArrayToBuffer(b);\n    buffer.writeUInt32LE(split.lo32, offset);\n    buffer.writeUInt32LE(split.hi32, offset + 4);\n    return 8;\n  }\n}\nexports.NearUInt64 = NearUInt64;\n/**\n * Represent an unsigned 64-bit integer in big-endian format when\n * encoded and as a near integral JavaScript Number when decoded.\n *\n * *Factory*: {@link module:Layout.nu64be|nu64be}\n *\n * **NOTE** Values with magnitude greater than 2^52 may not decode to\n * the exact value of the encoded representation.\n *\n * @augments {Layout}\n */\nclass NearUInt64BE extends Layout {\n  constructor(property) {\n    super(8, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    const buffer = uint8ArrayToBuffer(b);\n    const hi32 = buffer.readUInt32BE(offset);\n    const lo32 = buffer.readUInt32BE(offset + 4);\n    return roundedInt64(hi32, lo32);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    const split = divmodInt64(src);\n    const buffer = uint8ArrayToBuffer(b);\n    buffer.writeUInt32BE(split.hi32, offset);\n    buffer.writeUInt32BE(split.lo32, offset + 4);\n    return 8;\n  }\n}\nexports.NearUInt64BE = NearUInt64BE;\n/**\n * Represent a signed 64-bit integer in little-endian format when\n * encoded and as a near integral JavaScript Number when decoded.\n *\n * *Factory*: {@link module:Layout.ns64|ns64}\n *\n * **NOTE** Values with magnitude greater than 2^52 may not decode to\n * the exact value of the encoded representation.\n *\n * @augments {Layout}\n */\nclass NearInt64 extends Layout {\n  constructor(property) {\n    super(8, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    const buffer = uint8ArrayToBuffer(b);\n    const lo32 = buffer.readUInt32LE(offset);\n    const hi32 = buffer.readInt32LE(offset + 4);\n    return roundedInt64(hi32, lo32);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    const split = divmodInt64(src);\n    const buffer = uint8ArrayToBuffer(b);\n    buffer.writeUInt32LE(split.lo32, offset);\n    buffer.writeInt32LE(split.hi32, offset + 4);\n    return 8;\n  }\n}\nexports.NearInt64 = NearInt64;\n/**\n * Represent a signed 64-bit integer in big-endian format when\n * encoded and as a near integral JavaScript Number when decoded.\n *\n * *Factory*: {@link module:Layout.ns64be|ns64be}\n *\n * **NOTE** Values with magnitude greater than 2^52 may not decode to\n * the exact value of the encoded representation.\n *\n * @augments {Layout}\n */\nclass NearInt64BE extends Layout {\n  constructor(property) {\n    super(8, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    const buffer = uint8ArrayToBuffer(b);\n    const hi32 = buffer.readInt32BE(offset);\n    const lo32 = buffer.readUInt32BE(offset + 4);\n    return roundedInt64(hi32, lo32);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    const split = divmodInt64(src);\n    const buffer = uint8ArrayToBuffer(b);\n    buffer.writeInt32BE(split.hi32, offset);\n    buffer.writeUInt32BE(split.lo32, offset + 4);\n    return 8;\n  }\n}\nexports.NearInt64BE = NearInt64BE;\n/**\n * Represent a 32-bit floating point number in little-endian format.\n *\n * *Factory*: {@link module:Layout.f32|f32}\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass Float extends Layout {\n  constructor(property) {\n    super(4, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readFloatLE(offset);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeFloatLE(src, offset);\n    return 4;\n  }\n}\nexports.Float = Float;\n/**\n * Represent a 32-bit floating point number in big-endian format.\n *\n * *Factory*: {@link module:Layout.f32be|f32be}\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass FloatBE extends Layout {\n  constructor(property) {\n    super(4, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readFloatBE(offset);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeFloatBE(src, offset);\n    return 4;\n  }\n}\nexports.FloatBE = FloatBE;\n/**\n * Represent a 64-bit floating point number in little-endian format.\n *\n * *Factory*: {@link module:Layout.f64|f64}\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass Double extends Layout {\n  constructor(property) {\n    super(8, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readDoubleLE(offset);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeDoubleLE(src, offset);\n    return 8;\n  }\n}\nexports.Double = Double;\n/**\n * Represent a 64-bit floating point number in big-endian format.\n *\n * *Factory*: {@link module:Layout.f64be|f64be}\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass DoubleBE extends Layout {\n  constructor(property) {\n    super(8, property);\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    return uint8ArrayToBuffer(b).readDoubleBE(offset);\n  }\n  /** @override */\n  encode(src, b, offset = 0) {\n    uint8ArrayToBuffer(b).writeDoubleBE(src, offset);\n    return 8;\n  }\n}\nexports.DoubleBE = DoubleBE;\n/**\n * Represent a contiguous sequence of a specific layout as an Array.\n *\n * *Factory*: {@link module:Layout.seq|seq}\n *\n * @param {Layout} elementLayout - initializer for {@link\n * Sequence#elementLayout|elementLayout}.\n *\n * @param {(Number|ExternalLayout)} count - initializer for {@link\n * Sequence#count|count}.  The parameter must be either a positive\n * integer or an instance of {@link ExternalLayout}.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass Sequence extends Layout {\n  constructor(elementLayout, count, property) {\n    if (!(elementLayout instanceof Layout)) {\n      throw new TypeError('elementLayout must be a Layout');\n    }\n    if (!(count instanceof ExternalLayout && count.isCount() || Number.isInteger(count) && 0 <= count)) {\n      throw new TypeError('count must be non-negative integer ' + 'or an unsigned integer ExternalLayout');\n    }\n    let span = -1;\n    if (!(count instanceof ExternalLayout) && 0 < elementLayout.span) {\n      span = count * elementLayout.span;\n    }\n    super(span, property);\n    /** The layout for individual elements of the sequence. */\n    this.elementLayout = elementLayout;\n    /** The number of elements in the sequence.\n     *\n     * This will be either a non-negative integer or an instance of\n     * {@link ExternalLayout} for which {@link\n     * ExternalLayout#isCount|isCount()} is `true`. */\n    this.count = count;\n  }\n  /** @override */\n  getSpan(b, offset = 0) {\n    if (0 <= this.span) {\n      return this.span;\n    }\n    let span = 0;\n    let count = this.count;\n    if (count instanceof ExternalLayout) {\n      count = count.decode(b, offset);\n    }\n    if (0 < this.elementLayout.span) {\n      span = count * this.elementLayout.span;\n    } else {\n      let idx = 0;\n      while (idx < count) {\n        span += this.elementLayout.getSpan(b, offset + span);\n        ++idx;\n      }\n    }\n    return span;\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    const rv = [];\n    let i = 0;\n    let count = this.count;\n    if (count instanceof ExternalLayout) {\n      count = count.decode(b, offset);\n    }\n    while (i < count) {\n      rv.push(this.elementLayout.decode(b, offset));\n      offset += this.elementLayout.getSpan(b, offset);\n      i += 1;\n    }\n    return rv;\n  }\n  /** Implement {@link Layout#encode|encode} for {@link Sequence}.\n   *\n   * **NOTE** If `src` is shorter than {@link Sequence#count|count} then\n   * the unused space in the buffer is left unchanged.  If `src` is\n   * longer than {@link Sequence#count|count} the unneeded elements are\n   * ignored.\n   *\n   * **NOTE** If {@link Layout#count|count} is an instance of {@link\n   * ExternalLayout} then the length of `src` will be encoded as the\n   * count after `src` is encoded. */\n  encode(src, b, offset = 0) {\n    const elo = this.elementLayout;\n    const span = src.reduce((span, v) => {\n      return span + elo.encode(v, b, offset + span);\n    }, 0);\n    if (this.count instanceof ExternalLayout) {\n      this.count.encode(src.length, b, offset);\n    }\n    return span;\n  }\n}\nexports.Sequence = Sequence;\n/**\n * Represent a contiguous sequence of arbitrary layout elements as an\n * Object.\n *\n * *Factory*: {@link module:Layout.struct|struct}\n *\n * **NOTE** The {@link Layout#span|span} of the structure is variable\n * if any layout in {@link Structure#fields|fields} has a variable\n * span.  When {@link Layout#encode|encoding} we must have a value for\n * all variable-length fields, or we wouldn't be able to figure out\n * how much space to use for storage.  We can only identify the value\n * for a field when it has a {@link Layout#property|property}.  As\n * such, although a structure may contain both unnamed fields and\n * variable-length fields, it cannot contain an unnamed\n * variable-length field.\n *\n * @param {Layout[]} fields - initializer for {@link\n * Structure#fields|fields}.  An error is raised if this contains a\n * variable-length field for which a {@link Layout#property|property}\n * is not defined.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @param {Boolean} [decodePrefixes] - initializer for {@link\n * Structure#decodePrefixes|property}.\n *\n * @throws {Error} - if `fields` contains an unnamed variable-length\n * layout.\n *\n * @augments {Layout}\n */\nclass Structure extends Layout {\n  constructor(fields, property, decodePrefixes) {\n    if (!(Array.isArray(fields) && fields.reduce((acc, v) => acc && v instanceof Layout, true))) {\n      throw new TypeError('fields must be array of Layout instances');\n    }\n    if ('boolean' === typeof property && undefined === decodePrefixes) {\n      decodePrefixes = property;\n      property = undefined;\n    }\n    /* Verify absence of unnamed variable-length fields. */\n    for (const fd of fields) {\n      if (0 > fd.span && undefined === fd.property) {\n        throw new Error('fields cannot contain unnamed variable-length layout');\n      }\n    }\n    let span = -1;\n    try {\n      span = fields.reduce((span, fd) => span + fd.getSpan(), 0);\n    } catch (e) {\n      // ignore error\n    }\n    super(span, property);\n    /** The sequence of {@link Layout} values that comprise the\n     * structure.\n     *\n     * The individual elements need not be the same type, and may be\n     * either scalar or aggregate layouts.  If a member layout leaves\n     * its {@link Layout#property|property} undefined the\n     * corresponding region of the buffer associated with the element\n     * will not be mutated.\n     *\n     * @type {Layout[]} */\n    this.fields = fields;\n    /** Control behavior of {@link Layout#decode|decode()} given short\n     * buffers.\n     *\n     * In some situations a structure many be extended with additional\n     * fields over time, with older installations providing only a\n     * prefix of the full structure.  If this property is `true`\n     * decoding will accept those buffers and leave subsequent fields\n     * undefined, as long as the buffer ends at a field boundary.\n     * Defaults to `false`. */\n    this.decodePrefixes = !!decodePrefixes;\n  }\n  /** @override */\n  getSpan(b, offset = 0) {\n    if (0 <= this.span) {\n      return this.span;\n    }\n    let span = 0;\n    try {\n      span = this.fields.reduce((span, fd) => {\n        const fsp = fd.getSpan(b, offset);\n        offset += fsp;\n        return span + fsp;\n      }, 0);\n    } catch (e) {\n      throw new RangeError('indeterminate span');\n    }\n    return span;\n  }\n  /** @override */\n  decode(b, offset = 0) {\n    checkUint8Array(b);\n    const dest = this.makeDestinationObject();\n    for (const fd of this.fields) {\n      if (undefined !== fd.property) {\n        dest[fd.property] = fd.decode(b, offset);\n      }\n      offset += fd.getSpan(b, offset);\n      if (this.decodePrefixes && b.length === offset) {\n        break;\n      }\n    }\n    return dest;\n  }\n  /** Implement {@link Layout#encode|encode} for {@link Structure}.\n   *\n   * If `src` is missing a property for a member with a defined {@link\n   * Layout#property|property} the corresponding region of the buffer is\n   * left unmodified. */\n  encode(src, b, offset = 0) {\n    const firstOffset = offset;\n    let lastOffset = 0;\n    let lastWrote = 0;\n    for (const fd of this.fields) {\n      let span = fd.span;\n      lastWrote = 0 < span ? span : 0;\n      if (undefined !== fd.property) {\n        const fv = src[fd.property];\n        if (undefined !== fv) {\n          lastWrote = fd.encode(fv, b, offset);\n          if (0 > span) {\n            /* Read the as-encoded span, which is not necessarily the\n             * same as what we wrote. */\n            span = fd.getSpan(b, offset);\n          }\n        }\n      }\n      lastOffset = offset;\n      offset += span;\n    }\n    /* Use (lastOffset + lastWrote) instead of offset because the last\n     * item may have had a dynamic length and we don't want to include\n     * the padding between it and the end of the space reserved for\n     * it. */\n    return lastOffset + lastWrote - firstOffset;\n  }\n  /** @override */\n  fromArray(values) {\n    const dest = this.makeDestinationObject();\n    for (const fd of this.fields) {\n      if (undefined !== fd.property && 0 < values.length) {\n        dest[fd.property] = values.shift();\n      }\n    }\n    return dest;\n  }\n  /**\n   * Get access to the layout of a given property.\n   *\n   * @param {String} property - the structure member of interest.\n   *\n   * @return {Layout} - the layout associated with `property`, or\n   * undefined if there is no such property.\n   */\n  layoutFor(property) {\n    if ('string' !== typeof property) {\n      throw new TypeError('property must be string');\n    }\n    for (const fd of this.fields) {\n      if (fd.property === property) {\n        return fd;\n      }\n    }\n    return undefined;\n  }\n  /**\n   * Get the offset of a structure member.\n   *\n   * @param {String} property - the structure member of interest.\n   *\n   * @return {Number} - the offset in bytes to the start of `property`\n   * within the structure, or undefined if `property` is not a field\n   * within the structure.  If the property is a member but follows a\n   * variable-length structure member a negative number will be\n   * returned.\n   */\n  offsetOf(property) {\n    if ('string' !== typeof property) {\n      throw new TypeError('property must be string');\n    }\n    let offset = 0;\n    for (const fd of this.fields) {\n      if (fd.property === property) {\n        return offset;\n      }\n      if (0 > fd.span) {\n        offset = -1;\n      } else if (0 <= offset) {\n        offset += fd.span;\n      }\n    }\n    return undefined;\n  }\n}\nexports.Structure = Structure;\n/**\n * An object that can provide a {@link\n * Union#discriminator|discriminator} API for {@link Union}.\n *\n * **NOTE** This is an abstract base class; you can create instances\n * if it amuses you, but they won't support the {@link\n * UnionDiscriminator#encode|encode} or {@link\n * UnionDiscriminator#decode|decode} functions.\n *\n * @param {string} [property] - Default for {@link\n * UnionDiscriminator#property|property}.\n *\n * @abstract\n */\nclass UnionDiscriminator {\n  constructor(property) {\n    /** The {@link Layout#property|property} to be used when the\n     * discriminator is referenced in isolation (generally when {@link\n     * Union#decode|Union decode} cannot delegate to a specific\n     * variant). */\n    this.property = property;\n  }\n  /** Analog to {@link Layout#decode|Layout decode} for union discriminators.\n   *\n   * The implementation of this method need not reference the buffer if\n   * variant information is available through other means. */\n  decode(b, offset) {\n    throw new Error('UnionDiscriminator is abstract');\n  }\n  /** Analog to {@link Layout#decode|Layout encode} for union discriminators.\n   *\n   * The implementation of this method need not store the value if\n   * variant information is maintained through other means. */\n  encode(src, b, offset) {\n    throw new Error('UnionDiscriminator is abstract');\n  }\n}\nexports.UnionDiscriminator = UnionDiscriminator;\n/**\n * An object that can provide a {@link\n * UnionDiscriminator|discriminator API} for {@link Union} using an\n * unsigned integral {@link Layout} instance located either inside or\n * outside the union.\n *\n * @param {ExternalLayout} layout - initializes {@link\n * UnionLayoutDiscriminator#layout|layout}.  Must satisfy {@link\n * ExternalLayout#isCount|isCount()}.\n *\n * @param {string} [property] - Default for {@link\n * UnionDiscriminator#property|property}, superseding the property\n * from `layout`, but defaulting to `variant` if neither `property`\n * nor layout provide a property name.\n *\n * @augments {UnionDiscriminator}\n */\nclass UnionLayoutDiscriminator extends UnionDiscriminator {\n  constructor(layout, property) {\n    if (!(layout instanceof ExternalLayout && layout.isCount())) {\n      throw new TypeError('layout must be an unsigned integer ExternalLayout');\n    }\n    super(property || layout.property || 'variant');\n    /** The {@link ExternalLayout} used to access the discriminator\n     * value. */\n    this.layout = layout;\n  }\n  /** Delegate decoding to {@link UnionLayoutDiscriminator#layout|layout}. */\n  decode(b, offset) {\n    return this.layout.decode(b, offset);\n  }\n  /** Delegate encoding to {@link UnionLayoutDiscriminator#layout|layout}. */\n  encode(src, b, offset) {\n    return this.layout.encode(src, b, offset);\n  }\n}\nexports.UnionLayoutDiscriminator = UnionLayoutDiscriminator;\n/**\n * Represent any number of span-compatible layouts.\n *\n * *Factory*: {@link module:Layout.union|union}\n *\n * If the union has a {@link Union#defaultLayout|default layout} that\n * layout must have a non-negative {@link Layout#span|span}.  The span\n * of a fixed-span union includes its {@link\n * Union#discriminator|discriminator} if the variant is a {@link\n * Union#usesPrefixDiscriminator|prefix of the union}, plus the span\n * of its {@link Union#defaultLayout|default layout}.\n *\n * If the union does not have a default layout then the encoded span\n * of the union depends on the encoded span of its variant (which may\n * be fixed or variable).\n *\n * {@link VariantLayout#layout|Variant layout}s are added through\n * {@link Union#addVariant|addVariant}.  If the union has a default\n * layout, the span of the {@link VariantLayout#layout|layout\n * contained by the variant} must not exceed the span of the {@link\n * Union#defaultLayout|default layout} (minus the span of a {@link\n * Union#usesPrefixDiscriminator|prefix disriminator}, if used).  The\n * span of the variant will equal the span of the union itself.\n *\n * The variant for a buffer can only be identified from the {@link\n * Union#discriminator|discriminator} {@link\n * UnionDiscriminator#property|property} (in the case of the {@link\n * Union#defaultLayout|default layout}), or by using {@link\n * Union#getVariant|getVariant} and examining the resulting {@link\n * VariantLayout} instance.\n *\n * A variant compatible with a JavaScript object can be identified\n * using {@link Union#getSourceVariant|getSourceVariant}.\n *\n * @param {(UnionDiscriminator|ExternalLayout|Layout)} discr - How to\n * identify the layout used to interpret the union contents.  The\n * parameter must be an instance of {@link UnionDiscriminator}, an\n * {@link ExternalLayout} that satisfies {@link\n * ExternalLayout#isCount|isCount()}, or {@link UInt} (or {@link\n * UIntBE}).  When a non-external layout element is passed the layout\n * appears at the start of the union.  In all cases the (synthesized)\n * {@link UnionDiscriminator} instance is recorded as {@link\n * Union#discriminator|discriminator}.\n *\n * @param {(Layout|null)} defaultLayout - initializer for {@link\n * Union#defaultLayout|defaultLayout}.  If absent defaults to `null`.\n * If `null` there is no default layout: the union has data-dependent\n * length and attempts to decode or encode unrecognized variants will\n * throw an exception.  A {@link Layout} instance must have a\n * non-negative {@link Layout#span|span}, and if it lacks a {@link\n * Layout#property|property} the {@link\n * Union#defaultLayout|defaultLayout} will be a {@link\n * Layout#replicate|replica} with property `content`.\n *\n * @param {string} [property] - initializer for {@link\n * Layout#property|property}.\n *\n * @augments {Layout}\n */\nclass Union extends Layout {\n  constructor(discr, defaultLayout, property) {\n    let discriminator;\n    if (discr instanceof UInt || discr instanceof UIntBE) {\n      discriminator = new UnionLayoutDiscriminator(new OffsetLayout(discr));\n    } else if (discr instanceof ExternalLayout && discr.isCount()) {\n      discriminator = new UnionLayoutDiscriminator(discr);\n    } else if (!(discr instanceof UnionDiscriminator)) {\n      throw new TypeError('discr must be a UnionDiscriminator ' + 'or an unsigned integer layout');\n    } else {\n      discriminator = discr;\n    }\n    if (undefined === defaultLayout) {\n      defaultLayout = null;\n    }\n    if (!(null === defaultLayout || defaultLayout instanceof Layout)) {\n      throw new TypeError('defaultLayout must be null or a Layout');\n    }\n    if (null !== defaultLayout) {\n      if (0 > defaultLayout.span) {\n        throw new Error('defaultLayout must have constant span');\n      }\n      if (undefined === defaultLayout.property) {\n        defaultLayout = defaultLayout.replicate('content');\n      }\n    }\n    /* The union span can be estimated only if there's a default\n     * layout.  The union spans its default layout, plus any prefix\n     * variant layout.  By construction both layouts, if present, have\n     * non-negative span. */\n    let span = -1;\n    if (defaultLayout) {\n      span = defaultLayout.span;\n      if (0 <= span && (discr instanceof UInt || discr instanceof UIntBE)) {\n        span += discriminator.layout.span;\n      }\n    }\n    super(span, property);\n    /** The interface for the discriminator value in isolation.\n     *\n     * This a {@link UnionDiscriminator} either passed to the\n     * constructor or synthesized from the `discr` constructor\n     * argument.  {@link\n     * Union#usesPrefixDiscriminator|usesPrefixDiscriminator} will be\n     * `true` iff the `discr` parameter was a non-offset {@link\n     * Layout} instance. */\n    this.discriminator = discriminator;\n    /** `true` if the {@link Union#discriminator|discriminator} is the\n     * first field in the union.\n     *\n     * If `false` the discriminator is obtained from somewhere\n     * else. */\n    this.usesPrefixDiscriminator = discr instanceof UInt || discr instanceof UIntBE;\n    /** The layout for non-discriminator content when the value of the\n     * discriminator is not recognized.\n     *\n     * This is the value passed to the constructor.  It is\n     * structurally equivalent to the second component of {@link\n     * Union#layout|layout} but may have a different property\n     * name. */\n    this.defaultLayout = d