duktape/src-input/builtins.yaml

#
#  Built-in objects
#

# YAML conventions:
#
#   - Indent by two, indent lists of objects too.
#   - Quoted used for keys, explicit string values, hex data, attributes.
#     Not used for classes, built-in ID values, etc, unless necessary.
#   - Double quotes used throughout to allow escaping.
#
# Top level object format is mostly self explanatory, a few notes:
#
#    - The "id" string is used for referencing objects from property table
#    - Class names must match array in genbuiltins.py
#    - If the top level object is a function:
#      - varargs: if true, function is vararg (nargs = DUK_VARARGS)
#      - nargs: nargs (ignored if varargs true); if missing, default from 'length' property
#      - magic: see below
#      - native: native function name
#      - callable: true/false, depending on function
#      - constructable: true/false, depending on function
#      - special_call: true/false, used for .call(), .apply(), etc which
#        need special casing in runtime call handling
#    - To disable an object without removing its metadata, you can
#      use 'disable: true'.
#    - If the object is dependent on Duktape configuration, you can make the
#      object optional using e.g. 'present_if: DUK_USE_BUFFEROBJECT_SUPPORT'.
#      If the value is a list, the object is present if all listed options are
#      enabled (logical AND).
#    - If the object needs a DUK_BIDX_xxx define in Duktape source code, which
#      also implies it'll get a slot in thr->builtins[] array, use 'bidx: true'.
#
# Property format:
#
#    - key: verbatim string key, codepoints U+0000...U+00FF map to bytes,
#           so that \u0082 is 0x82 prefix, \u00FF is 0xFF prefix, etc.  Key
#           can also be a symbol, with the same format as for symbol values.
#    - value: see below
#    - attributes: string of format /w?e?c?a?/, e.g. "wc" is writable and
#                  configurable
#        + w: writable
#        + e: enumerable
#        + c: configurable
#        + a: accessor (determined automatically, not necessary to give explicitly)
#    - auto_lightfunc: if true (which is default), function property may be
#      automatically converted to a lightfunc if other automatic lightfunc
#      conversion criteria are met; use "auto_lightfunc: false" to prevent
#      lightfunc conversion
#    - May also have feature tags like "es6: true" to indicate property
#      is related to a specific standard
#    - To disable a property without removing its metadata, you can use
#      'disable: true'.
#    - If the property is dependent on Duktape configuration, you can make the
#      property optional using e.g. 'present_if: DUK_USE_BUFFEROBJECT_SUPPORT'.
#      List of options is interpreted as for objects (logical AND).
#
# Property value format:
#
#    - Ecmascript undefined:
#      - type: undefined
#    - Plain YAML/JSON null (parses as Python None)
#      - treated as Ecmascript null
#    - Plain string:
#      - treated as plain string, string data as with keys
#    - Plain symbol:
#      - type: symbol
#      - variant: global, wellknown, hidden, userhidden
#      - string: symbol string without any prefix
#      - NOTE: ES2015 well-known symbols are local symbols with 'string' as
#        their description, and a fixed suffix never overlapping with
#        runtime local symbols
#      - NOTE: "hidden symbols" are Duktape specific internal properties
#        (called just internal properties in 1.x)
#    - Plain number:
#      - treated as a fastint/ieee double
#    - IEEE double:
#      - type: double
#      - bytes: IEEE bytes in big endian format, hex encoded
#      - NOTE: if you define a NaN, make sure it is in the Duktape normalized
#        form (see bi_global 'NaN' property): otherwise strange things will
#        happen with packed duk_tval
#    - Buffer:
#      - type: buffer
#      - NOTE: not supported yet, type is reserved
#    - Pointer:
#      - type: pointer
#      - NOTE: not supported yet, type is reserved
#    - Lightfunc:
#      - type: lightfunc
#      - native: native function name
#      - magic: -128 to 127
#      - length: 0 to 15
#      - nargs: 0 to 14; or varargs: true
#      - varargs: if true, target has variable arguments
#    - Reference to a built-in object:
#      - type: object
#        id: ID string of target object
#    - Accessor (setter/getter):
#      - type: accessor
#      - getter_id: object ID of getter
#      - setter_id: object ID of setter
#    - Native function shorthand; alternative to defining a function as a
#      native object and referencing it using an ID:
#      - type: function (implicitly callable)
#      - callable: default is true
#      - constructable: default is false
#      - native: native function name
#      - length: function .length (optional, defaults to 0)
#      - nargs: function nargs (optional, defaults to length)
#      - varargs: if true, function is vararg (nargs = DUK_VARARGS)
#      - magic: magic value for function (see below)
#      - name: optional, provides .name property (non-writable, non-enumerable, non-configurable)
#      - special_call: recognized in shorthand
#    - Accessor (setter/getter) shorthand:
#      - type: accessor
#      - callable: default is true
#      - constructable: default is false
#      - getter: native function name
#      - setter: native function name
#      - getter_magic: magic value for getter
#      - setter_magic: magic value for setter
#      - getter_nargs: nargs value for getter
#      - setter_nargs: nargs value for setter
#      - getter_length: length value for getter (0 if missing)
#      - setter_length: length value for setter (0 if missing)
#    - Structured object shorthand:
#      - type: structured
#      - value: arbitrary JSON-like value
#      - NOTE: value is converted into object(s) with properties
#        similarly to JSON.parse() results: properties will be
#        writable, enumerable, and configurable, inherit from
#        Object.prototype, etc.
#
# Magic format:
#
#    - Plain number: direct magic value
#    - Array iterator magic:
#      - type: array_iter
#      - funcname: function name, e.g. "forEach"
#    - Built-in object index:
#      - type: bidx
#      - id: id of built-object, idx to thr->builtins[]
#    - One-argument math function:
#      - type: math_onearg
#      - funcname: name of function, e.g. "cos"
#    - Two-argument math function:
#      - type: math_twoarg
#      - funcname: name of function, e.g. "atan2"
#    - Typed array constructor
#      - type: typedarray_constructor
#      - elem: element type, e.g. "int8"
#      - shift: shift for element size (0 = 1 byte element, 2 = 4 byte element etc)

objects:

  # internal prototype: implementation specific
  #  Smjs: Object.prototype
  #  Rhino: Object.prototype
  #  V8: *not* Object.prototype, but prototype chain includes Object.prototype
  # external prototype: apparently not set
  # external constructor: apparently not set
  # internal class: implemented specific
  #  Smjs: "global"
  #  Rhino: "global"
  #  V8: "global"
  #
  # E5 Sections B.2.1 and B.2.2 describe non-standard properties which are
  # included below but flagged as extensions.

  - id: bi_global
    class: global
    internal_prototype: bi_object_prototype
    bidx: true

    properties:
      # 'global' binding giving easy to access to the global object.
      # Not yet standard, see https://github.com/tc39/proposal-global.
      - key: "global"
        value:
          type: object
          id: bi_global
        attributes: "wc"
        # This could be stripped when DUK_USE_GLOBAL_BUILTIN is disabled
        # but keep for now (the property is quite fundamental).
        present_if: DUK_USE_GLOBAL_BINDING

      - key: "NaN"
        value:
          type: double
          bytes: "7ff8000000000000"  # DBL_NAN
        attributes: ""
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "Infinity"
        value:
          type: double
          bytes: "7ff0000000000000"  # DBL_POSITIVE_INFINITY
        attributes: ""
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "undefined"
        value:
          type: undefined
        attributes: ""
        # This could be stripped when DUK_USE_GLOBAL_BUILTIN is disabled
        # ("void 0" is the same and safer) but it's commonly used so keep.

      - key: "Object"
        value:
          type: object
          id: bi_object_constructor
        present_if: DUK_USE_OBJECT_BUILTIN
      - key: "Function"
        value:
          type: object
          id: bi_function_constructor
        present_if: DUK_USE_FUNCTION_BUILTIN
      - key: "Array"
        value:
          type: object
          id: bi_array_constructor
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "String"
        value:
          type: object
          id: bi_string_constructor
        present_if: DUK_USE_STRING_BUILTIN
      - key: "Boolean"
        value:
          type: object
          id: bi_boolean_constructor
        present_if: DUK_USE_BOOLEAN_BUILTIN
      - key: "Number"
        value:
          type: object
          id: bi_number_constructor
        present_if: DUK_USE_NUMBER_BUILTIN
      - key: "Date"
        value:
          type: object
          id: bi_date_constructor
        present_if: DUK_USE_DATE_BUILTIN
      - key: "RegExp"
        value:
          type: object
          id: bi_regexp_constructor
        present_if: DUK_USE_REGEXP_SUPPORT
      - key: "Error"
        value:
          type: object
          id: bi_error_constructor
      - key: "EvalError"
        value:
          type: object
          id: bi_eval_error_constructor
      - key: "RangeError"
        value:
          type: object
          id: bi_range_error_constructor
      - key: "ReferenceError"
        value:
          type: object
          id: bi_reference_error_constructor
      - key: "SyntaxError"
        value:
          type: object
          id: bi_syntax_error_constructor
      - key: "TypeError"
        value:
          type: object
          id: bi_type_error_constructor
      - key: "URIError"
        value:
          type: object
          id: bi_uri_error_constructor
      - key: "Math"
        value:
          type: object
          id: bi_math
        present_if: DUK_USE_MATH_BUILTIN
      - key: "JSON"
        value:
          type: object
          id: bi_json
        present_if: DUK_USE_JSON_BUILTIN

      # Duktape specific
      - key: "Duktape"
        value:
          type: object
          id: bi_duktape
        duktape: true
        # Remains present even when disabled: needed for error augmentation internally.
        #present_if: DUK_USE_DUKTAPE_BUILTIN

      # ES2015
      - key: "Proxy"
        value:
          type: object
          id: bi_proxy_constructor
        es6: true
        present_if: DUK_USE_ES6_PROXY
      - key: "Reflect"
        value:
          type: object
          id: bi_reflect
        es6: true
        present_if: DUK_USE_REFLECT_BUILTIN
      - key: "Symbol"
        value:
          type: object
          id: bi_symbol_constructor
        es6: true
        present_if: DUK_USE_SYMBOL_BUILTIN
      - key: "Promise"
        value:
          type: object
          id: bi_promise_constructor
        es6: true
        present_if: DUK_USE_PROMISE_BUILTIN

      # Node.js Buffer
      - key: "Buffer"
        value:
          type: object
          id: bi_nodejs_buffer_constructor
        nodejs_buffer: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT

      # TypedArray
      - key: "ArrayBuffer"
        value:
          type: object
          id: bi_arraybuffer_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "DataView"
        value:
          type: object
          id: bi_dataview_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Int8Array"
        value:
          type: object
          id: bi_int8array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Uint8Array"
        value:
          type: object
          id: bi_uint8array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Uint8ClampedArray"
        value:
          type: object
          id: bi_uint8clampedarray_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Int16Array"
        value:
          type: object
          id: bi_int16array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Uint16Array"
        value:
          type: object
          id: bi_uint16array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Int32Array"
        value:
          type: object
          id: bi_int32array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Uint32Array"
        value:
          type: object
          id: bi_uint32array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Float32Array"
        value:
          type: object
          id: bi_float32array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "Float64Array"
        value:
          type: object
          id: bi_float64array_constructor
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT

      # Functions
      - key: "eval"
        value:
          type: function
          native: duk_bi_global_object_eval
          length: 1
          magic: 15  # see duk_js_call.c
          special_call: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "parseInt"
        value:
          type: function
          native: duk_bi_global_object_parse_int
          length: 2
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "parseFloat"
        value:
          type: function
          native: duk_bi_global_object_parse_float
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "isNaN"
        value:
          type: function
          native: duk_bi_global_object_is_nan
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "isFinite"
        value:
          type: function
          native: duk_bi_global_object_is_finite
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "decodeURI"
        value:
          type: function
          native: duk_bi_global_object_decode_uri
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "decodeURIComponent"
        value:
          type: function
          native: duk_bi_global_object_decode_uri_component
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "encodeURI"
        value:
          type: function
          native: duk_bi_global_object_encode_uri
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN
      - key: "encodeURIComponent"
        value:
          type: function
          native: duk_bi_global_object_encode_uri_component
          length: 1
        present_if: DUK_USE_GLOBAL_BUILTIN

      # Non-standard extensions: E5 Sections B.2.1 and B.2.2
      #
      # "length" is not specified explicitly in E5 but it follows the
      # general argument count rule.  V8 also agrees on the lengths.

      - key: "escape"
        value:
          type: function
          native: duk_bi_global_object_escape
          length: 1
        section_b: true
        present_if:
          - DUK_USE_SECTION_B
          - DUK_USE_GLOBAL_BUILTIN
      - key: "unescape"
        value:
          type: function
          native: duk_bi_global_object_unescape
          length: 1
        section_b: true
        present_if:
          - DUK_USE_SECTION_B
          - DUK_USE_GLOBAL_BUILTIN

      # Encoding API: https://encoding.spec.whatwg.org/
      - key: "TextEncoder"
        value:
          type: object
          id: bi_textencoder_constructor
        encoding_api: true
        present_if: DUK_USE_ENCODING_BUILTINS
      - key: "TextDecoder"
        value:
          type: object
          id: bi_textdecoder_constructor
        encoding_api: true
        present_if: DUK_USE_ENCODING_BUILTINS

      # High resolution time API: https://www.w3.org/TR/hr-time/
      # Firefox and Chrome: accessor with 'ec' attributes, setter
      # allows overwrite.
      # Use data property with 'wec' for now.
      - key: "performance"
        value:
          type: object
          id: bi_performance
        attributes: "wec"
        performance_api: true
        present_if: DUK_USE_PERFORMANCE_BUILTIN

  - id: bi_global_env
    class: ObjEnv
    duktape: true
    bidx: true

    # The internal 'target' property is now part of duk_hobjenv and handled
    # specially by RAM built-in init code.  ROM built-ins provide an explicit
    # initializer based on these properties.

    objenv_target: bi_global
    objenv_has_this: 0

    properties: []

  - id: bi_object_constructor
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_object_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_OBJECT_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_object_prototype
        attributes: ""
      - key: "name"
        value: "Object"
        attributes: "c"

      - key: "getPrototypeOf"
        value:
          type: function
          native: duk_bi_object_getprototype_shared
          length: 1
          magic: 1
      - key: "setPrototypeOf"
        value:
          type: function
          native: duk_bi_object_setprototype_shared
          length: 2
          magic: 1
        es6: true
      - key: "getOwnPropertyDescriptor"
        value:
          type: function
          native: duk_bi_object_constructor_get_own_property_descriptor
          length: 2
          magic: 0
      - key: "getOwnPropertyNames"
        value:
          type: function
          native: duk_bi_object_constructor_keys_shared
          length: 1
          magic: 1
      - key: "assign"
        value:
          type: function
          native: duk_bi_object_constructor_assign
          length: 2
          varargs: true
        es6: true
        present_if: DUK_USE_ES6
      - key: "create"
        value:
          type: function
          native: duk_bi_object_constructor_create
          length: 2
      - key: "defineProperty"
        value:
          type: function
          native: duk_bi_object_constructor_define_property
          length: 3
          magic: 0
      - key: "defineProperties"
        value:
          type: function
          native: duk_bi_object_constructor_define_properties
          length: 2
      - key: "seal"
        value:
          type: function
          native: duk_bi_object_constructor_seal_freeze_shared
          length: 1
          magic: 0
      - key: "freeze"
        value:
          type: function
          native: duk_bi_object_constructor_seal_freeze_shared
          length: 1
          magic: 1
      - key: "preventExtensions"
        value:
          type: function
          native: duk_bi_object_constructor_prevent_extensions
          length: 1
          magic: 0
      - key: "isSealed"
        value:
          type: function
          native: duk_bi_object_constructor_is_sealed_frozen_shared
          length: 1
          magic: 0
      - key: "isFrozen"
        value:
          type: function
          native: duk_bi_object_constructor_is_sealed_frozen_shared
          length: 1
          magic: 1
      - key: "isExtensible"
        value:
          type: function
          native: duk_bi_object_constructor_is_extensible
          length: 1
          magic: 0
      - key: "keys"
        value:
          type: function
          native: duk_bi_object_constructor_keys_shared
          length: 1
          magic: 0
      - key: "getOwnPropertySymbols"
        value:
          type: function
          native: duk_bi_object_constructor_keys_shared
          length: 1
          magic: 2
        es6: true
        present_if: DUK_USE_ES6
      - key: "is"
        value:
          type: function
          native: duk_bi_object_constructor_is
          length: 2
          nargs: 2
        es6: true
        present_if: DUK_USE_ES6

  - id: bi_object_prototype
    class: Object
    # internal_prototype: null
    bidx: true
    # Present even when DUK_USE_OBJECT_BUILTIN disabled.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_object_constructor
        attributes: "wc"
        present_if: DUK_USE_OBJECT_BUILTIN

      - key: "__proto__"
        value:
          type: accessor
          getter: duk_bi_object_getprototype_shared
          setter: duk_bi_object_setprototype_shared
          getter_nargs: 0
          setter_nargs: 1
          getter_magic: 0
          setter_magic: 0
        attributes: "c"  # configurable in ES2015, also V8
        es6: true  # also non-standard legacy
        present_if: DUK_USE_OBJECT_BUILTIN

      - key: "toString"
        value:
          type: function
          native: duk_bi_object_prototype_to_string
          length: 0
        present_if: DUK_USE_OBJECT_BUILTIN
      - key: "toLocaleString"
        value:
          type: function
          native: duk_bi_object_prototype_to_locale_string
          length: 0
        present_if: DUK_USE_OBJECT_BUILTIN
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_object_prototype_value_of
          length: 0
        present_if: DUK_USE_OBJECT_BUILTIN
      - key: "hasOwnProperty"
        value:
          type: function
          native: duk_bi_object_prototype_has_own_property
          length: 1
        present_if: DUK_USE_OBJECT_BUILTIN
      - key: "isPrototypeOf"
        value:
          type: function
          native: duk_bi_object_prototype_is_prototype_of
          length: 1
        present_if: DUK_USE_OBJECT_BUILTIN
      - key: "propertyIsEnumerable"
        value:
          type: function
          native: duk_bi_object_prototype_property_is_enumerable
          length: 1
        present_if: DUK_USE_OBJECT_BUILTIN

      # __defineGetter, __defineSetter__, __lookupGetter__, __lookupSetter__: ES2017 Annex B
      # https://tc39.github.io/ecma262/#sec-additional-properties-of-the-object.prototype-object

      - key: "__defineGetter__"
        value:
          type: function
          native: duk_bi_object_prototype_defineaccessor
          length: 2
          magic: 0  # define getter
        present_if: DUK_USE_ES8
      - key: "__defineSetter__"
        value:
          type: function
          native: duk_bi_object_prototype_defineaccessor
          length: 2
          magic: 1  # define setter
        present_if: DUK_USE_ES8
      - key: "__lookupGetter__"
        value:
          type: function
          native: duk_bi_object_prototype_lookupaccessor
          length: 1
          magic: 0  # lookup getter
        present_if: DUK_USE_ES8
      - key: "__lookupSetter__"
        value:
          type: function
          native: duk_bi_object_prototype_lookupaccessor
          length: 1
          magic: 1  # lookup setter
        present_if: DUK_USE_ES8

  - id: bi_function_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_function_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_FUNCTION_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_function_prototype
        attributes: ""
      - key: "name"
        value: "Function"
        attributes: "c"

  # Note, unlike other prototype objects, Function.prototype is itself
  # a Function and callable.  When invoked, it accepts any arguments
  # and returns undefined.  It cannot be called as a constructor.
  # See E5 Section 15.3.4.
  - id: bi_function_prototype
    class: Function
    internal_prototype: bi_object_prototype
    native: duk_bi_function_prototype
    callable: true
    constructable: false
    bidx: true
    nargs: 0  # given explicitly because .length is optional
    # Present even when DUK_USE_FUNCTION_BUILTIN disabled.

    properties:
      - key: "length"
        value: 0
        attributes: "c"
        present_if: DUK_USE_FUNCTION_BUILTIN
      - key: "constructor"
        value:
          type: object
          id: bi_function_constructor
        attributes: "wc"
        present_if: DUK_USE_FUNCTION_BUILTIN

      # In ES2015 Function.prototype.name is not writable, but is configurable.
      - key: "name"
        value: ""
        attributes: "c"
        #present_if: DUK_USE_FUNCTION_BUILTIN  # Kept even when prototype is otherwise empty to guarantee a .name for functions

      # test262 ch15/15.3/15.3.4/15.3.4.2/S15.3.4.2_A11 checks that Function.prototype.toString.length
      # is zero, cannot find specification support for that but 0 is a good value.
      - key: "toString"
        value:
          type: function
          native: duk_bi_function_prototype_to_string
          length: 0
        present_if: DUK_USE_FUNCTION_BUILTIN
      - key: "apply"
        value:
          type: function
          native: duk_bi_function_prototype_apply
          length: 2
          magic: 1  # see duk_js_call.c
          special_call: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        present_if: DUK_USE_FUNCTION_BUILTIN
      - key: "call"
        value:
          type: function
          native: duk_bi_function_prototype_call
          length: 1
          magic: 0  # see duk_js_call.c
          varargs: true
          special_call: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        present_if: DUK_USE_FUNCTION_BUILTIN
      - key: "bind"
        value:
          type: function
          native: duk_bi_function_prototype_bind
          length: 1
          varargs: true
        present_if: DUK_USE_FUNCTION_BUILTIN

      # ES2015
      #- key:  # @@hasInstance
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.hasInstance"
      #  value: XXX
      #  es6: true

  # Duktape specific %NativeFunctionPrototype% which provides some getters.
  #
  - id: bi_native_function_prototype
    class: Object
    internal_prototype: bi_function_prototype
    native: duk_bi_function_prototype
    bidx: true
    duktape: true
    # Present even when DUK_USE_FUNCTION_BUILTIN disabled.

    properties:
      - key: "length"
        value:
          type: accessor
          getter: duk_bi_native_function_length
          getter_nargs: 0
          getter_magic: 0
          # Setter undefined: direct write fails (defineProperty() works).
          # This mimics ES2015 function (own property) .length which is
          # not writable but configurable.
        attributes: "c"
        #present_if: DUK_USE_FUNCTION_BUILTIN  # Kept to guarantee a .length for lightfuncs
      - key: "name"
        value:
          type: accessor
          getter: duk_bi_native_function_name
          getter_nargs: 0
          getter_magic: 0
          # Setter undefined: direct write fails (defineProperty() works).
          # This mimics ES2015 function (own property) .name which is
          # not writable but configurable.
        attributes: "c"
        #present_if: DUK_USE_FUNCTION_BUILTIN  # Kept to guarantee a .name for lightfuncs

  - id: bi_array_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_array_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_ARRAY_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_array_prototype
        attributes: ""
      - key: "name"
        value: "Array"
        attributes: "c"
      - key: "isArray"
        value:
          type: function
          native: duk_bi_array_constructor_is_array
          length: 1

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_array_prototype
    class: Array
    internal_prototype: bi_object_prototype
    bidx: true
    # Present even when DUK_USE_ARRAY_BUILTIN disabled.

    # An array prototype is an Array itself.  It has a length property initialized to 0,
    # with property attributes: writable, non-configurable, non-enumerable.  The attributes
    # are not specified very explicitly for the prototype, but are given for Array instances
    # in E5 Section 15.4.5.2 (and this matches the behavior of e.g. V8).

    properties:
      # With duk_harray added to the internal representation, .length is now virtual.
      #- key: "length"
      #  value: 0
      #  attributes: "w"
      - key: "constructor"
        value:
          type: object
          id: bi_array_constructor
        attributes: "wc"
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "toString"
        value:
          type: function
          native: duk_bi_array_prototype_to_string
          length: 0
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "toLocaleString"
        value:
          type: function
          native: duk_bi_array_prototype_join_shared
          length: 0
          magic: 1  # magic: to_locale_string, here 1
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "concat"
        value:
          type: function
          native: duk_bi_array_prototype_concat
          length: 1
          varargs: true
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "join"
        value:
          type: function
          native: duk_bi_array_prototype_join_shared
          length: 1
          magic: 0  # magic: to_locale_string, here 0
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "pop"
        value:
          type: function
          native: duk_bi_array_prototype_pop
          length: 0
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "push"
        value:
          type: function
          native: duk_bi_array_prototype_push
          length: 1
          varargs: true
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "reverse"
        value:
          type: function
          native: duk_bi_array_prototype_reverse
          length: 0
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "shift"
        value:
          type: function
          native: duk_bi_array_prototype_shift
          length: 0
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "slice"
        value:
          type: function
          native: duk_bi_array_prototype_slice
          length: 2
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "sort"
        value:
          type: function
          native: duk_bi_array_prototype_sort
          length: 1
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "splice"
        value:
          type: function
          native: duk_bi_array_prototype_splice
          length: 2
          varargs: true
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "unshift"
        value:
          type: function
          native: duk_bi_array_prototype_unshift
          length: 1
          varargs: true
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "indexOf"
        value:
          type: function
          native: duk_bi_array_prototype_indexof_shared
          length: 1
          varargs: true
          magic: 1  # magic: idx_step = +1
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "lastIndexOf"
        value:
          type: function
          native: duk_bi_array_prototype_indexof_shared
          length: 1
          varargs: true
          magic: -1  # magic: idx_step = -1
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "every"
        value:
          type: function
          native: duk_bi_array_prototype_iter_shared
          length: 1
          nargs: 2
          magic:
            type: array_iter
            funcname: "every"  # BI_ARRAY_ITER_EVERY
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "some"
        value:
          type: function
          native: duk_bi_array_prototype_iter_shared
          length: 1
          nargs: 2
          magic:
            type: array_iter
            funcname: "some"  # BI_ARRAY_ITER_SOME
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "forEach"
        value:
          type: function
          native: duk_bi_array_prototype_iter_shared
          length: 1
          nargs: 2
          magic:
            type: array_iter
            funcname: "forEach"  # BI_ARRAY_ITER_FOREACH
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "map"
        value:
          type: function
          native: duk_bi_array_prototype_iter_shared
          length: 1
          nargs: 2
          magic:
            type: array_iter
            funcname: "map"  # BI_ARRAY_ITER_MAP
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "filter"
        value:
          type: function
          native: duk_bi_array_prototype_iter_shared
          length: 1
          nargs: 2
          magic:
            type: array_iter
            funcname: filter  # BI_ARRAY_ITER_FILTER
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "reduce"
        value:
          type: function
          native: duk_bi_array_prototype_reduce_shared
          length: 1
          varargs: true
          magic: 1  # magic: idx_step = +1
        present_if: DUK_USE_ARRAY_BUILTIN
      - key: "reduceRight"
        value:
          type: function
          native: duk_bi_array_prototype_reduce_shared
          length: 1
          varargs: true
          magic: -1  # magic: idx_step = -1
        present_if: DUK_USE_ARRAY_BUILTIN

      #- key:  # @@iterator
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.iterator"
      #  value: XXX
      #  es6: true
      #- key:  # @@unscopables
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.unscopables"
      #  value: XXX
      #  es6: true

  - id: bi_string_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_string_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_STRING_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_string_prototype
        attributes: ""
      - key: "name"
        value: "String"
        attributes: "c"

      - key: "fromCharCode"
        value:
          type: function
          native: duk_bi_string_constructor_from_char_code
          length: 1
          varargs: true
      - key: "fromCodePoint"
        value:
          type: function
          native: duk_bi_string_constructor_from_code_point
          length: 1
          varargs: true
        present_if: DUK_USE_ES6

  - id: bi_string_prototype
    class: String
    internal_prototype: bi_object_prototype
    bidx: true
    # Present even when DUK_USE_STRING_BUILTIN disabled.

    # String prototype is a String instance and must have length value 0.
    # This is supplied by the String instance virtual properties and does
    # not need to be included in init data.
    #
    # Unlike Array.prototype.length, String.prototype.length has the default
    # "length" attributes of built-in objects: non-writable, non-enumerable,
    # non-configurable.

    #length: 0,  # omitted; non-writable, non-enumerable, non-configurable

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_string_constructor
        attributes: "wc"
        present_if: DUK_USE_STRING_BUILTIN

      # Internal empty string value.  Note that this value is not writable
      # which prevents a String instance's internal value also from being
      # written with standard methods.  The internal code creating String
      # instances has no such issues.
      - key:
          type: symbol
          variant: hidden
          string: "Value"
        value: ""
        attributes: ""
        duktape: true

      - key: "toString"
        value:
          type: function
          native: duk_bi_string_prototype_to_string
          length: 0
        present_if: DUK_USE_STRING_BUILTIN
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_string_prototype_to_string  # share native function, behavior is identical
          length: 0
        present_if: DUK_USE_STRING_BUILTIN
      - key: "charAt"
        value:
          type: function
          native: duk_bi_string_prototype_char_at
          length: 1
        present_if: DUK_USE_STRING_BUILTIN
      - key: "charCodeAt"
        value:
          type: function
          native: duk_bi_string_prototype_char_code_at
          length: 1
          magic: 0
        present_if: DUK_USE_STRING_BUILTIN
      - key: "codePointAt"
        value:
          type: function
          native: duk_bi_string_prototype_char_code_at
          length: 1
          magic: 1
        es6: true
        present_if:
          - DUK_USE_ES6
          - DUK_USE_STRING_BUILTIN
      - key: "concat"
        value:
          type: function
          native: duk_bi_string_prototype_concat
          length: 1
          varargs: true
        present_if: DUK_USE_STRING_BUILTIN
      - key: "indexOf"
        value:
          type: function
          native: duk_bi_string_prototype_indexof_shared
          length: 1
          nargs: 2
          magic: 0  # magic = 0 -> indexOf
        present_if: DUK_USE_STRING_BUILTIN
      - key: "lastIndexOf"
        value:
          type: function
          native: duk_bi_string_prototype_indexof_shared
          length: 1
          nargs: 2
          magic: 1  # magic = 1 -> lastIndexOf
        present_if: DUK_USE_STRING_BUILTIN
      - key: "localeCompare"
        value:
          type: function
          native: duk_bi_string_prototype_locale_compare
          length: 1
        present_if: DUK_USE_STRING_BUILTIN
      - key: "match"
        value:
          type: function
          native: duk_bi_string_prototype_match
          length: 1
        present_if:
          - DUK_USE_STRING_BUILTIN
          - DUK_USE_REGEXP_SUPPORT
      - key: "replace"
        value:
          type: function
          native: duk_bi_string_prototype_replace
          length: 2
        present_if: DUK_USE_STRING_BUILTIN
      - key: "search"
        value:
          type: function
          native: duk_bi_string_prototype_search
          length: 1
        present_if:
          - DUK_USE_STRING_BUILTIN
          - DUK_USE_REGEXP_SUPPORT
      - key: "slice"
        value:
          type: function
          native: duk_bi_string_prototype_slice
          length: 2
        present_if: DUK_USE_STRING_BUILTIN
      - key: "split"
        value:
          type: function
          native: duk_bi_string_prototype_split
          length: 2
        present_if: DUK_USE_STRING_BUILTIN
      - key: "substring"
        value:
          type: function
          native: duk_bi_string_prototype_substring
          length: 2
        present_if: DUK_USE_STRING_BUILTIN
      - key: "toLowerCase"
        value:
          type: function
          native: duk_bi_string_prototype_caseconv_shared
          length: 0
          magic: 0  # magic = uppercase
        present_if: DUK_USE_STRING_BUILTIN
      - key: "toLocaleLowerCase"
        value:
          type: function
          native: duk_bi_string_prototype_caseconv_shared
          length: 0
          magic: 0  # magic = uppercase; no locale specific conversion now
        present_if: DUK_USE_STRING_BUILTIN
      - key: "toUpperCase"
        value:
          type: function
          native: duk_bi_string_prototype_caseconv_shared
          length: 0
          magic: 1  # magic = uppercase
        present_if: DUK_USE_STRING_BUILTIN
      - key: "toLocaleUpperCase"
        value:
          type: function
          native: duk_bi_string_prototype_caseconv_shared
          length: 0
          magic: 1  # magic = uppercase; no locale specific conversion now
        present_if: DUK_USE_STRING_BUILTIN
      - key: "trim"
        value:
          type: function
          native: duk_bi_string_prototype_trim
          length: 0
        present_if: DUK_USE_STRING_BUILTIN
      - key: "repeat"
        value:
          type: function
          native: duk_bi_string_prototype_repeat
          length: 1
          nargs: 1
        present_if:
          - DUK_USE_ES6
          - DUK_USE_STRING_BUILTIN
      - key: "startsWith"
        value:
          type: function
          native: duk_bi_string_prototype_startswith_endswith
          length: 1
          nargs: 2
          magic: 0  # 0=startsWith
        present_if:
          - DUK_USE_ES6
          - DUK_USE_STRING_BUILTIN
      - key: "endsWith"
        value:
          type: function
          native: duk_bi_string_prototype_startswith_endswith
          length: 1
          nargs: 2
          magic: 1  # 1=endsWith
        present_if:
          - DUK_USE_ES6
          - DUK_USE_STRING_BUILTIN
      - key: "includes"
        value:
          type: function
          native: duk_bi_string_prototype_includes
          length: 1
          nargs: 2
        present_if:
          - DUK_USE_ES6
          - DUK_USE_STRING_BUILTIN

      # Non-standard extension: E5 Section B.2.3

      - key: "substr"
        value:
          type: function
          native: duk_bi_string_prototype_substr
          length: 2
        section_b: true
        present_if:
          - DUK_USE_STRING_BUILTIN
          - DUK_USE_SECTION_B

      #- key:  # @@iterator
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.iterator"
      #  value: XXX
      #  es6: true

  - id: bi_boolean_constructor
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_boolean_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_BOOLEAN_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_boolean_prototype
        attributes: ""
      - key: "name"
        value: "Boolean"
        attributes: "c"

  - id: bi_boolean_prototype
    class: Boolean
    internal_prototype: bi_object_prototype
    bidx: true
    # Present even when DUK_USE_BOOLEAN_BUILTIN disabled.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_boolean_constructor
        attributes: "wc"
        present_if: DUK_USE_BOOLEAN_BUILTIN

      # Internal false boolean value.  Note that this value is not writable
      # which prevents a Boolean instance's internal value also from being
      # written with standard methods.  The internal code creating Boolean
      # instances has no such issues.
      - key:
          type: symbol
          variant: hidden
          string: "Value"
        value: false
        attributes: ""
        duktape: true

      - key: "toString"
        value:
          type: function
          native: duk_bi_boolean_prototype_tostring_shared
          length: 0
          magic: 1  # magic = coerce_tostring
        present_if: DUK_USE_BOOLEAN_BUILTIN
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_boolean_prototype_tostring_shared
          length: 0
          magic: 0  # magic = coerce_tostring
        present_if: DUK_USE_BOOLEAN_BUILTIN

  - id: bi_number_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_number_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_NUMBER_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_number_prototype
        attributes: ""
      - key: "name"
        value: "Number"
        attributes: "c"
      - key: "MAX_VALUE"
        value:
          type: double
          bytes: "7fefffffffffffff"  # DBL_MAX_DOUBLE
        attributes: ""
      - key: "MIN_VALUE"
        value:
          type: double
          bytes: "0000000000000001"  # DBL_MIN_DOUBLE
        attributes: ""
      - key: "NaN"
        value:
          type: double
          bytes: "7ff8000000000000"  # DBL_NAN
        attributes: ""
      - key: "POSITIVE_INFINITY"
        value:
          type: double
          bytes: "7ff0000000000000"  # DBL_POSITIVE_INFINITY
        attributes: ""
      - key: "NEGATIVE_INFINITY"
        value:
          type: double
          bytes: "fff0000000000000"  # DBL_NEGATIVE_INFINITY
        attributes: ""

  - id: bi_number_prototype
    class: Number
    internal_prototype: bi_object_prototype
    bidx: true
    # Present even when DUK_USE_NUMBER_BUILTIN disabled.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_number_constructor
        attributes: "wc"
        present_if: DUK_USE_NUMBER_BUILTIN

    # Internal 0.0 number value.  Note that this value is not writable
    # which prevents a Number instance's internal value also from being
    # written with standard methods.  The internal code creating Number
    # instances has no such issues.
      - key:
          type: symbol
          variant: hidden
          string: "Value"
        value: 0.0
        attributes: ""
        duktape: true

      - key: "toString"
        value:
          type: function
          native: duk_bi_number_prototype_to_string
          length: 1
        present_if: DUK_USE_NUMBER_BUILTIN
      - key: "toLocaleString"
        value:
          type: function
          native: duk_bi_number_prototype_to_locale_string
          length: 1
        present_if: DUK_USE_NUMBER_BUILTIN
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_number_prototype_value_of
          length: 0
        present_if: DUK_USE_NUMBER_BUILTIN
      - key: "toFixed"
        value:
          type: function
          native: duk_bi_number_prototype_to_fixed
          length: 1
        present_if: DUK_USE_NUMBER_BUILTIN
      - key: "toExponential"
        value:
          type: function
          native: duk_bi_number_prototype_to_exponential
          length: 1
        present_if: DUK_USE_NUMBER_BUILTIN
      - key: "toPrecision"
        value:
          type: function
          native: duk_bi_number_prototype_to_precision
          length: 1
        present_if: DUK_USE_NUMBER_BUILTIN

  - id: bi_date_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_date_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_DATE_BUILTIN

    properties:
      - key: "length"
        value: 7
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_date_prototype
        attributes: ""
      - key: "name"
        value: "Date"
        attributes: "c"

      - key: "parse"
        value:
          type: function
          native: duk_bi_date_constructor_parse
          length: 1
      - key: "UTC"
        value:
          type: function
          native: duk_bi_date_constructor_utc
          length: 7
          varargs: true
      - key: "now"
        value:
          type: function
          native: duk_bi_date_constructor_now
          length: 0

  - id: bi_date_prototype
    class: Date
    internal_prototype: bi_object_prototype
    bidx: true
    present_if: DUK_USE_DATE_BUILTIN

    # The Date prototype is an instance of Date with [[PrimitiveValue]] NaN.
    #
    # Setters with optional arguments must be varargs functions because
    # they must detect the number of parameters actually given (cannot
    # assume parameters not given are undefined).
    #
    # Date.prototype.valueOf() and Date.prototype.getTime() have identical
    # behavior so they share the same C function, but have different
    # function instances.
    #
    # Getters, setters, and string conversion functions use shared native
    # helpers and the function "magic" value is used to pass flags and
    # parameters to the helpers.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_date_constructor
        attributes: "wc"

      # Internal date value (E5 Section 15.9.5).
      #
      # Note: the value is writable, as you can e.g. do the following (V8):
      #  > Date.prototype.toString()
      #  "Invalid Date"
      #  > Date.prototype.setYear(2010)
      #  1262296800000
      #  > Date.prototype.toString()
      #  "Fri Jan 01 2010 00:00:00 GMT+0200 (EET)"

      - key:
          type: symbol
          variant: hidden
          string: "Value"
        value:
          type: double
          bytes: "7ff8000000000000"  # DBL_NAN
        attributes: "w"
        duktape: true

      # NOTE: The magic values for Date prototype are special.  The actual control
      # flags needed for the built-ins don't fit into LIGHTFUNC magic field, so
      # the values here are indices to duk__date_magics[] in duk_bi_date.c which
      # contains the actual control flags.  Magic values here must be kept in strict
      # sync with duk_bi_date.c!

      - key: "toString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 0
      - key: "toDateString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 1
      - key: "toTimeString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 2
      - key: "toLocaleString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 3
      - key: "toLocaleDateString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 4
      - key: "toLocaleTimeString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 5
      - key: "toUTCString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 6
      - key: "toISOString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 7
      - key: "toJSON"
        value:
          type: function
          native: duk_bi_date_prototype_to_json
          length: 1
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_date_prototype_value_of
          length: 0
      - key: "getTime"
        value:
          type: function
          native: duk_bi_date_prototype_value_of  # Native function shared on purpose
          length: 0
      - key: "getFullYear"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 8
      - key: "getUTCFullYear"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 9
      - key: "getMonth"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 10
      - key: "getUTCMonth"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 11
      - key: "getDate"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 12
      - key: "getUTCDate"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 13
      - key: "getDay"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 14
      - key: "getUTCDay"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 15
      - key: "getHours"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 16
      - key: "getUTCHours"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 17
      - key: "getMinutes"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 18
      - key: "getUTCMinutes"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 19
      - key: "getSeconds"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 20
      - key: "getUTCSeconds"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 21
      - key: "getMilliseconds"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 22
      - key: "getUTCMilliseconds"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 23
      - key: "getTimezoneOffset"
        value:
          type: function
          native: duk_bi_date_prototype_get_timezone_offset
          length: 0
      - key: "setTime"
        value:
          type: function
          native: duk_bi_date_prototype_set_time
          length: 1
      - key: "setMilliseconds"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 1
          magic: 24
      - key: "setUTCMilliseconds"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 1
          magic: 25
      - key: "setSeconds"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 2
          varargs: true
          magic: 26
      - key: "setUTCSeconds"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 2
          varargs: true
          magic: 27
      - key: "setMinutes"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 3
          varargs: true
          magic: 28
      - key: "setUTCMinutes"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 3
          varargs: true
          magic: 29
      - key: "setHours"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 4
          varargs: true
          magic: 30
      - key: "setUTCHours"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 4
          varargs: true
          magic: 31
      - key: "setDate"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 1
          magic: 32
      - key: "setUTCDate"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 1
          magic: 33
      - key: "setMonth"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 2
          varargs: true
          magic: 34
      - key: "setUTCMonth"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 2
          varargs: true
          magic: 35
      - key: "setFullYear"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 3
          varargs: true
          magic: 36
      - key: "setUTCFullYear"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 3
          varargs: true
          magic: 37
      # Note: toGMTString() is required to initially be the same Function
      # object as the initial Date.prototype.toUTCString.  In other words
      # the following must compare true:
      #
      #   Date.prototype.toGMTString === Date.prototype.toUTCString.
      #
      # This is currently handled using a small tweak in duk_hthread_builtins.c
      # (for RAM objects) and genbuiltins.py (for ROM objects).
      #
      # Note that while Smjs respects the requirement in E5 Section B.2.6,
      # V8 does not.
      - key: "toGMTString"
        value:
          type: function
          native: duk_bi_date_prototype_tostring_shared
          length: 0
          magic: 6
        section_b: true

      # Non-standard extensions: E5 Section B.2.4, B.2.5, B.2.6
      #
      # "length" values are not given explicitly but follows the general rule.
      # The lengths below agree with V8.

      - key: "getYear"
        value:
          type: function
          native: duk_bi_date_prototype_get_shared
          length: 0
          magic: 38
        section_b: true
      - key: "setYear"
        value:
          type: function
          native: duk_bi_date_prototype_set_shared
          length: 1
          magic: 39
        section_b: true

      #- key:  # @@toPrimitive
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.toPrimitive"
      #  value: XXX
      #  es6: true

  - id: bi_regexp_constructor
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_regexp_constructor
    callable: true
    constructable: true
    bidx: true
    present_if: DUK_USE_REGEXP_SUPPORT

    properties:
      - key: "length"
        value: 2
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_regexp_prototype
        attributes: ""
      - key: "name"
        value: "RegExp"
        attributes: "c"

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_regexp_prototype
    class: Object  # Object in ES2015; RegExp in ES5
    internal_prototype: bi_object_prototype
    bidx: true
    present_if: DUK_USE_REGEXP_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_regexp_constructor
        attributes: "wc"

      # In ES2015 RegExp.prototype is no longer a RegExp instance.

      # "lastIndex" is writable, even in the RegExp.prototype object.
      # This matches at least V8.
      - key: "lastIndex"
        value: 0
        attributes: "w"

      - key: "exec"
        value:
          type: function
          native: duk_bi_regexp_prototype_exec
          length: 1
      - key: "test"
        value:
          type: function
          native: duk_bi_regexp_prototype_test
          length: 1
      - key: "toString"
        value:
          type: function
          native: duk_bi_regexp_prototype_tostring
          length: 0

      # In ES2015 .source, .global, .ignoreCase, etc are accessors.
      # .flags is ES2015 but must be present because the constructor now
      # relies on its presence for e.g. new RegExp(/foo/gim).

      - key: "flags"
        value:
          type: accessor
          getter: duk_bi_regexp_prototype_flags
          getter_nargs: 0
          getter_magic: 0
          # setter undefined
        attributes: "c"
        es6: true

      - key: "source"
        value:
          type: accessor
          getter: duk_bi_regexp_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 16  # default case in shared getter (value quite arbitrary)
          # setter undefined
        attributes: "c"
      - key: "global"
        value:
          type: accessor
          getter: duk_bi_regexp_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 0
          # setter undefined
        attributes: "c"
      - key: "ignoreCase"
        value:
          type: accessor
          getter: duk_bi_regexp_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 1
          # setter undefined
        attributes: "c"
      - key: "multiline"
        value:
          type: accessor
          getter: duk_bi_regexp_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 2
          # setter undefined
        attributes: "c"
      # .sticky and .unicode commented out; don't provide until implemented
      # to avoid interfering with application feature detection code
      #- key: "sticky"
      #  value:
      #    type: accessor
      #    getter: duk_bi_regexp_prototype_shared_getter
      #    getter_nargs: 0
      #    getter_magic: 3
      #    # setter undefined
      #  attributes: "c"
      #  es6: true
      #  present_if: DUK_USE_ES6
      #- key: "unicode"
      #  value:
      #    type: accessor
      #    getter: duk_bi_regexp_prototype_shared_getter
      #    getter_nargs: 0
      #    getter_magic: 4
      #    # setter undefined
      #  attributes: "c"
      #  es6: true
      #  present_if: DUK_USE_ES6

      #- key:  # @@match
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.match"
      #  value: XXX
      #  es6: true
      #- key:  # @@replace
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.replace"
      #  value: XXX
      #  es6: true
      #- key:  # @@search
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.search"
      #  value: XXX
      #  es6: true
      #- key:  # @@split
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.split"
      #  value: XXX
      #  es6: true

  - id: bi_error_constructor
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_error_prototype
        attributes: ""
      - key: "name"
        value: "Error"
        attributes: "c"

  - id: bi_error_prototype
    class: Error
    internal_prototype: bi_object_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_error_constructor
        attributes: "wc"

      # Standard properties; property attributes:
      #
      # "message" is writable and deletable.  This matches the default
      # attributes of "wc".  V8 and Smjs both match this.
      #
      # "name" is writable and deletable.  This matches the default
      # attributes too.  Smjs behaves like this, but in V8 "name" is
      # non-writable:
      #
      #  > Object.getOwnPropertyDescriptor(Error.prototype, "name")
      #  { value: "Error",
      #    writable: false,
      #    enumerable: false,
      #    configurable: false }
      #
      # We go with the standard attributes ("wc").

      - key: "name"
        value: "Error"
      - key: "message"
        value: ""

      # Custom properties

      - key: "stack"
        value:
          type: accessor
          getter: duk_bi_error_prototype_stack_getter
          setter: duk_bi_error_prototype_stack_setter
          getter_nargs: 0
          setter_nargs: 1
          getter_magic: 0
          setter_magic: 0
        attributes: "c"
        duktape: true
      - key: "fileName"
        value:
          type: accessor
          getter: duk_bi_error_prototype_filename_getter
          setter: duk_bi_error_prototype_filename_setter
          getter_nargs: 0
          setter_nargs: 1
          getter_magic: 0
          setter_magic: 0
        attributes: "c"
        duktape: true
      - key: "lineNumber"
        value:
          type: accessor
          getter: duk_bi_error_prototype_linenumber_getter
          setter: duk_bi_error_prototype_linenumber_setter
          getter_nargs: 0
          setter_nargs: 1
          getter_magic: 0
          setter_magic: 0
        attributes: "c"
        duktape: true

      - key: "toString"
        value:
          type: function
          native: duk_bi_error_prototype_to_string
          length: 0

  # NOTE: Error subclass prototypes have an empty "message" property, even
  # though one is inherited already from Error prototype (E5 Section 15.11.7.10).
  #
  # V8 does not respect this: Error subclasses ("native Errors" in E5 spec)
  # do not have a "message" property at all.  Also, in V8 their "name" property
  # is not writable and configurable as E5 requires.

  - id: bi_eval_error_constructor
    class: Function
    internal_prototype: bi_error_constructor
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_eval_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_eval_error_prototype
        attributes: ""
      - key: "name"
        value: "EvalError"
        attributes: "c"

  - id: bi_eval_error_prototype
    class: Error
    internal_prototype: bi_error_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_eval_error_constructor
        attributes: "wc"
      - key: "name"
        value: "EvalError"
      - key: "message"
        value: ""

  - id: bi_range_error_constructor
    class: Function
    internal_prototype: bi_error_constructor
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_range_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_range_error_prototype
        attributes: ""
      - key: "name"
        value: "RangeError"
        attributes: "c"

  - id: bi_range_error_prototype
    class: Error
    internal_prototype: bi_error_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_range_error_constructor
        attributes: "wc"
      - key: "name"
        value: "RangeError"
      - key: "message"
        value: ""

  - id: bi_reference_error_constructor
    class: Function
    internal_prototype: bi_error_constructor
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_reference_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_reference_error_prototype
        attributes: ""
      - key: "name"
        value: "ReferenceError"
        attributes: "c"

  - id: bi_reference_error_prototype
    class: Error
    internal_prototype: bi_error_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_reference_error_constructor
        attributes: "wc"
      - key: "name"
        value: "ReferenceError"
      - key: "message"
        value: ""

  - id: bi_syntax_error_constructor
    class: Function
    internal_prototype: bi_error_constructor
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_syntax_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_syntax_error_prototype
        attributes: ""
      - key: "name"
        value: "SyntaxError"
        attributes: "c"

  - id: bi_syntax_error_prototype
    class: Error
    internal_prototype: bi_error_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_syntax_error_constructor
        attributes: "wc"
      - key: "name"
        value: "SyntaxError"
      - key: "message"
        value: ""

  - id: bi_type_error_constructor
    class: Function
    internal_prototype: bi_error_constructor
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_type_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_type_error_prototype
        attributes: ""
      - key: "name"
        value: "TypeError"
        attributes: "c"

  - id: bi_type_error_prototype
    class: Error
    internal_prototype: bi_error_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_type_error_constructor
        attributes: "wc"
      - key: "name"
        value: "TypeError"
      - key: "message"
        value: ""

  - id: bi_uri_error_constructor
    class: Function
    internal_prototype: bi_error_constructor
    native: duk_bi_error_constructor_shared
    callable: true
    constructable: true
    magic:
      type: bidx
      id: bi_uri_error_prototype
    bidx: true

    properties:
      - key: "length"
        value: 1
        attributes: "c"
      - key: "prototype"
        value:
          type: object
          id: bi_uri_error_prototype
        attributes: ""
      - key: "name"
        value: "URIError"
        attributes: "c"

  - id: bi_uri_error_prototype
    class: Error
    internal_prototype: bi_error_prototype
    bidx: true

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_uri_error_constructor
        attributes: "wc"
      - key: "name"
        value: "URIError"
      - key: "message"
        value: ""

  - id: bi_math
    class: Math
    internal_prototype: bi_object_prototype
    bidx: false
    present_if: DUK_USE_MATH_BUILTIN

    # apparently no external "prototype" property
    # apparently no external "constructor" property

    properties:
      - key: "E"
        value:
          type: double
          bytes: "4005bf0a8b145769"  # DBL_E
        attributes: ""
      - key: "LN10"
        value:
          type: double
          bytes: "40026bb1bbb55516"  # DBL_LN10
        attributes: ""
      - key: "LN2"
        value:
          type: double
          bytes: "3fe62e42fefa39ef"  # DBL_LN2
        attributes: ""
      - key: "LOG2E"
        value:
          type: double
          bytes: "3ff71547652b82fe"  # DBL_LOG2E
        attributes: ""
      - key: "LOG10E"
        value:
          type: double
          bytes: "3fdbcb7b1526e50e"  # DBL_LOG10E
        attributes: ""
      - key: "PI"
        value:
          type: double
          bytes: "400921fb54442d18"  # DBL_PI
        attributes: ""
      - key: "SQRT1_2"
        value:
          type: double
          bytes: "3fe6a09e667f3bcd"  # DBL_SQRT1_2
        attributes: ""
      - key: "SQRT2"
        value:
          type: double
          bytes: "3ff6a09e667f3bcd"  # DBL_SQRT2
        attributes: ""

      - key: "abs"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "fabs"
      - key: "acos"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "acos"
      - key: "asin"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "asin"
      - key: "atan"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "atan"
      - key: "atan2"
        value:
          type: function
          native: duk_bi_math_object_twoarg_shared
          length: 2
          magic:
            type: math_twoarg
            funcname: "atan2"
      - key: "cbrt"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "cbrt"
        es6: true
        present_if: DUK_USE_ES6
      - key: "ceil"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "ceil"
      - key: "clz32"
        value:
          type: function
          native: duk_bi_math_object_clz32
          length: 1
        es6: true
        present_if: DUK_USE_ES6
      - key: "cos"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "cos"
      - key: "exp"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "exp"
      - key: "floor"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "floor"
      - key: "hypot"
        value:
          type: function
          native: duk_bi_math_object_hypot
          length: 2
          varargs: true
        es6: true
        present_if: DUK_USE_ES6
      - key: "imul"
        value:
          type: function
          native: duk_bi_math_object_imul
          length: 2
        es6: true
        present_if: DUK_USE_ES6
      - key: "log"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "log"
      - key: "log2"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "log2"
        es6: true
        present_if: DUK_USE_ES6
      - key: "log10"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "log10"
        es6: true
        present_if: DUK_USE_ES6
      - key: "max"
        value:
          type: function
          native: duk_bi_math_object_max
          length: 2
          varargs: true
      - key: "min"
        value:
          type: function
          native: duk_bi_math_object_min
          length: 2
          varargs: true
      - key: "pow"
        value:
          type: function
          native: duk_bi_math_object_twoarg_shared
          length: 2
          magic:
            type: math_twoarg
            funcname: "pow"
      - key: "random"
        value:
          type: function
          native: duk_bi_math_object_random
          length: 0
      - key: "round"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "round"
      - key: "sign"
        value:
          type: function
          native: duk_bi_math_object_sign
          length: 1
        es6: true
        present_if: DUK_USE_ES6
      - key: "sin"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "sin"
      - key: "sqrt"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "sqrt"
      - key: "tan"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "tan"
      - key: "trunc"
        value:
          type: function
          native: duk_bi_math_object_onearg_shared
          length: 1
          magic:
            type: math_onearg
            funcname: "trunc"
        es6: true
        present_if: DUK_USE_ES6
      - key:
          type: symbol
          variant: wellknown
          string: "Symbol.toStringTag"
        value: "Math"
        attributes: "c"
        es6: true

  - id: bi_json
    class: JSON
    internal_prototype: bi_object_prototype
    bidx: false
    present_if:
      - DUK_USE_JSON_BUILTIN
      - DUK_USE_JSON_SUPPORT

    # apparently no external "prototype" property
    # apparently no external "constructor" property

    properties:
      - key: "parse"
        value:
          type: function
          native: duk_bi_json_object_parse
          length: 2
      - key: "stringify"
        value:
          type: function
          native: duk_bi_json_object_stringify
          length: 3

      #- key:  # @@toStringTag
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.toStringTag"
      #  value: XXX
      #  es6: true

  # E5 Section 13.2.3
  - id: bi_type_error_thrower
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_type_error_thrower
    callable: true
    constructable: false  # This is not clearly specified, but [[Construct]] is not set in E5 Section 13.2.3.
    bidx: true

    properties:
      - key: "length"
        value: 0
        attributes: "c"
      # Custom name, matches V8; ES2016 describes %ThrowTypeError% as being
      # anonymous.
      - key: "name"
        value: "ThrowTypeError"
        attributes: "c"
        duktape: true

  #
  #  Duktape-specific built-ins
  #

  - id: bi_duktape
    class: Object
    internal_prototype: bi_object_prototype
    duktape: true
    bidx: true
    #present_if: DUK_USE_DUKTAPE_BUILTIN  # Present even when properties disabled, error augmentation relies on it

    # There are a few properties not listed here:
    #   - "version" is added from parameter file automatically.
    #   - "env" is added dynamically at runtime.

    properties:
      - key: "Pointer"
        value:
          type: object
          id: bi_pointer_constructor
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "Thread"
        value:
          type: object
          id: bi_thread_constructor
        duktape: true
        present_if:
          - DUK_USE_COROUTINE_SUPPORT
          - DUK_USE_DUKTAPE_BUILTIN
      - key: "info"
        value:
          type: function
          native: duk_bi_duktape_object_info
          length: 1
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "act"
        value:
          type: function
          native: duk_bi_duktape_object_act
          length: 1
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "gc"
        value:
          type: function
          native: duk_bi_duktape_object_gc
          length: 1
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "fin"
        value:
          type: function
          native: duk_bi_duktape_object_fin
          length: 0
          varargs: true
        duktape: true
        present_if:
          - DUK_USE_FINALIZER_SUPPORT
          - DUK_USE_DUKTAPE_BUILTIN
      - key: "enc"
        value:
          type: function
          native: duk_bi_duktape_object_enc
          length: 0
          varargs: true
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "dec"
        value:
          type: function
          native: duk_bi_duktape_object_dec
          length: 0
          varargs: true
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "compact"
        value:
          type: function
          native: duk_bi_duktape_object_compact
          length: 1
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN

  - id: bi_thread_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_thread_constructor
    callable: true
    constructable: true
    duktape: true
    bidx: false
    present_if: DUK_USE_COROUTINE_SUPPORT

    properties:
      - key: "length"
        value: 1
        attributes: "c"
        duktape: true
      - key: "prototype"
        value:
          type: object
          id: bi_thread_prototype
        attributes: ""
        duktape: true
      - key: "name"
        value: "Thread"
        attributes: "c"
        duktape: true

      # "yield" is a reserved word but does not prevent its use as a property name
      - key: "yield"
        value:
          type: function
          native: duk_bi_thread_yield
          length: 2
        duktape: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        present_if: DUK_USE_COROUTINE_SUPPORT
      - key: "resume"
        value:
          type: function
          native: duk_bi_thread_resume
          length: 3
        duktape: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        present_if: DUK_USE_COROUTINE_SUPPORT
      - key: "current"
        value:
          type: function
          native: duk_bi_thread_current
          length: 0
        duktape: true
        present_if: DUK_USE_COROUTINE_SUPPORT

  - id: bi_thread_prototype
    class: Object
    internal_prototype: bi_object_prototype
    duktape: true
    bidx: true
    # Present even when DUK_USE_DUKTAPE_BUILTIN disabled.

    # Must be present even if coroutines are disabled for inheritance.
    # Because Duktape.Thread.prototype is missing, the only way to access
    # the prototype to e.g. add methods is to look it up from a thread
    # instance.

    # Note: we don't keep up with the E5 convention that prototype objects
    # are some faux instances of their type (e.g. Date.prototype is a Date
    # instance).
    #
    # Also, we don't currently have a "constructor" property because there is
    # no explicit constructor object.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_thread_constructor
        attributes: "wc"
        duktape: true
        present_if:
          - DUK_USE_COROUTINE_SUPPORT
          - DUK_USE_DUKTAPE_BUILTIN

      # toString() and valueOf() are inherited from Object.prototype

  - id: bi_pointer_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: true
    native: duk_bi_pointer_constructor
    callable: true
    constructable: true
    duktape: true
    bidx: false

    properties:
      - key: "length"
        value: 1
        attributes: "c"
        duktape: true
      - key: "prototype"
        value:
          type: object
          id: bi_pointer_prototype
        attributes: ""
        duktape: true
      - key: "name"
        value: "Pointer"
        attributes: "c"
        duktape: true

  - id: bi_pointer_prototype
    class: Pointer
    internal_prototype: bi_object_prototype
    duktape: true
    bidx: true
    # Present even when DUK_USE_DUKTAPE_BUILTIN disabled.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_pointer_constructor
        attributes: "wc"
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN

      - key: "toString"
        value:
          type: function
          native: duk_bi_pointer_prototype_tostring_shared
          length: 0
          magic: 1  # magic = to_string
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_pointer_prototype_tostring_shared
          length: 0
          magic: 0  # magic = to_string
        duktape: true
        present_if: DUK_USE_DUKTAPE_BUILTIN

  # This is an Error *instance* used to avoid allocation when a "double error" occurs.
  # The object is "frozen and sealed" to avoid code accidentally modifying the instance.
  # This is important because the error is rethrown as is.

  - id: bi_double_error
    class: Error
    internal_prototype: bi_error_prototype
    extensible: false
    duktape: true
    bidx: true

    # Note: this is the only non-extensible built-in, so there is special
    # post-tweak in duk_hthread_builtins.c to handle this.

    properties:
      - key: "name"
        value: "DoubleError"
        attributes: ""
        duktape: true
      - key: "message"
        value: "error in error handling"
        attributes: ""
        duktape: true

  #
  #  ES2015
  #

  - id: bi_proxy_constructor
    class: Function
    internal_prototype: bi_function_prototype
    # no external prototype
    native: duk_bi_proxy_constructor
    callable: true
    constructable: true
    es6: true
    bidx: false
    present_if: DUK_USE_ES6_PROXY

    properties:
      - key: "length"
        value: 2
        attributes: "c"
        es6: true
      - key: "name"
        value: "Proxy"
        attributes: "c"
        es6: true
      #- key: "revocable"
      #  value:
      #    type: function
      #    native: duk_bi_proxy_constructor_revocable
      #    length: 2
      #  es6: true

  - id: bi_reflect
    class: Object
    internal_prototype: bi_object_prototype
    bidx: false
    present_if: DUK_USE_REFLECT_BUILTIN

    properties:
      - key: "apply"
        value:
          type: function
          native: duk_bi_reflect_apply
          length: 3
          magic: 2  # see duk_js_call.c
          special_call: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        es6: true
      - key: "construct"
        value:
          type: function
          native: duk_bi_reflect_construct
          length: 2
          magic: 3  # see duk_js_call.c
          special_call: true
        auto_lightfunc: false  # automatic lightfunc conversion clashes with internal implementation
        es6: true
      - key: "defineProperty"
        value:
          type: function
          native: duk_bi_object_constructor_define_property
          length: 3
          magic: 1
        es6: true
      - key: "deleteProperty"
        value:
          type: function
          native: duk_bi_reflect_object_delete_property
          length: 2
        es6: true
      - key: "get"
        value:
          type: function
          native: duk_bi_reflect_object_get
          length: 2
          varargs: true
        es6: true
      - key: "getOwnPropertyDescriptor"
        value:
          type: function
          native: duk_bi_object_constructor_get_own_property_descriptor
          length: 2
          magic: 1
        es6: true
      - key: "getPrototypeOf"
        value:
          type: function
          native: duk_bi_object_getprototype_shared
          length: 1
          magic: 2
        es6: true
      - key: "has"
        value:
          type: function
          native: duk_bi_reflect_object_has
          length: 2
        es6: true
      - key: "isExtensible"
        value:
          type: function
          native: duk_bi_object_constructor_is_extensible
          length: 1
          magic: 1
        es6: true
      - key: "ownKeys"
        value:
          type: function
          native: duk_bi_object_constructor_keys_shared
          length: 1
          magic: 3
        es6: true
      - key: "preventExtensions"
        value:
          type: function
          native: duk_bi_object_constructor_prevent_extensions
          length: 1
          magic: 1
        es6: true
      - key: "set"
        value:
          type: function
          native: duk_bi_reflect_object_set
          length: 3
          varargs: true
        es6: true
      - key: "setPrototypeOf"
        value:
          type: function
          native: duk_bi_object_setprototype_shared
          length: 2
          magic: 2
        es6: true

  - id: bi_symbol_constructor
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_symbol_constructor_shared
    callable: true
    constructable: false  # new Symbol() not allowed
    es6: true
    nargs: 1
    magic: 0
    bidx: false
    present_if: DUK_USE_SYMBOL_BUILTIN

    properties:
      - key: "length"
        value: 0
        attributes: "c"
        es6: true
      - key: "name"
        value: "Symbol"
        attributes: "c"
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_symbol_prototype
        attributes: ""
        es6: true

      - key: "for"
        value:
          type: function
          native: duk_bi_symbol_constructor_shared
          magic: 1
          length: 1
          nargs: 1
        attributes: "wc"
        es6: true
      - key: "keyFor"
        value:
          type: function
          native: duk_bi_symbol_key_for
          length: 1
          nargs: 1
        attributes: "wc"
        es6: true

      #- key: "hasInstance"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.hasInstance"
      #  attributes: ""
      #  es6: true
      #- key: "isConcatSpreadable"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.isConcatSpreadable"
      #  attributes: ""
      #  es6: true
      - key: "iterator"
        value:
          type: symbol
          variant: wellknown
          string: "Symbol.iterator"
        attributes: ""
        es6: true
      #- key: "match"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.match"
      #  attributes: ""
      #  es6: true
      #- key: "replace"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.replace"
      #  attributes: ""
      #  es6: true
      #- key: "search"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.search"
      #  attributes: ""
      #  es6: true
      #- key: "species"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  attributes: ""
      #  es6: true
      #- key: "split"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.split"
      #  attributes: ""
      #  es6: true
      - key: "toPrimitive"
        value:
          type: symbol
          variant: wellknown
          string: "Symbol.toPrimitive"
        attributes: ""
        es6: true
      - key: "toStringTag"
        value:
          type: symbol
          variant: wellknown
          string: "Symbol.toStringTag"
        attributes: ""
        es6: true
      #- key: "unscopables"
      #  value:
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.unscopables"
      #  attributes: ""
      #  es6: true

  - id: bi_symbol_prototype
    class: Object
    internal_prototype: bi_object_prototype
    es6: true
    bidx: true
    # Present even when DUK_USE_SYMBOL_BUILTIN disabled so that symbol values
    # created from C code can inherit through the Symbol prototype.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_symbol_constructor
        attributes: "wc"
        es6: true
        present_if: DUK_USE_SYMBOL_BUILTIN

      - key: "toString"
        value:
          type: function
          native: duk_bi_symbol_tostring_shared
          nargs: 0
          magic: 0
        attributes: "wc"
        es6: true
        present_if: DUK_USE_SYMBOL_BUILTIN
      - key: "valueOf"
        value:
          type: function
          native: duk_bi_symbol_tostring_shared
          nargs: 0
          magic: 1
        attributes: "wc"
        es6: true
        present_if: DUK_USE_SYMBOL_BUILTIN
      - key:  # @@toPrimitive
          type: symbol
          variant: wellknown
          string: "Symbol.toPrimitive"
        value:
          type: function
          native: duk_bi_symbol_toprimitive
          nargs: 0  # hint is ignored
          length: 0
          name: "[Symbol.toPrimitive]"
        attributes: "c"
        es6: true
        present_if: DUK_USE_SYMBOL_BUILTIN
      - key:  # @@toStringTag
          type: symbol
          variant: wellknown
          string: "Symbol.toStringTag"
        value: "symbol"
        attributes: "c"
        es6: true
        present_if: DUK_USE_SYMBOL_BUILTIN

  - id: bi_promise_constructor
    class: Function
    internal_prototype: bi_function_prototype
    native: duk_bi_promise_constructor
    callable: true
    constructable: true
    es6: true
    nargs: 1
    magic: 0
    bidx: false
    present_if: DUK_USE_PROMISE_BUILTIN

    properties:
      - key: "length"
        value: 1
        attributes: "c"
        es6: true
      - key: "name"
        value: "Promise"
        attributes: "c"
        es6: true
      - key: 'prototype'
        value:
          type: object
          id: bi_promise_prototype
        attributes: ""
        es6: true
      - key: 'all'
        value:
          type: function
          native: duk_bi_promise_all
          length: 1
          varargs: false
        attributes: 'wc'
        es6: true
      - key: 'race'
        value:
          type: function
          native: duk_bi_promise_race
          length: 1
          varargs: false
        attributes: 'wc'
        es6: true
      - key: 'reject'
        value:
          type: function
          native: duk_bi_promise_reject
          length: 1
          varargs: false
        attributes: 'wc'
        es6: true
      - key: 'resolve'
        value:
          type: function
          native: duk_bi_promise_resolve
          length: 1
          varargs: false
        attributes: 'wc'
        es6: true
      # @@species
      # 'defer' is obsolete and not implemented:
      # https://developer.mozilla.org/en-US/docs/Mozilla/JavaScript_code_modules/Promise.jsm/Deferred.
      # 'accept' is obsolete and not implemented:
      #https://bugs.chromium.org/p/v8/issues/detail?id=3238

  - id: bi_promise_prototype
    class: Object
    internal_prototype: bi_object_prototype
    es6: true
    bidx: true
    present_if: DUK_USE_PROMISE_BUILTIN

    properties:
      - key: 'constructor'
        value:
          type: object
          id: bi_promise_constructor
        attributes: "wc"
        es6: true
      - key: 'catch'
        value:
          type: function
          native: duk_bi_promise_catch
          length: 1
          varargs: false
        attributes: 'wc'
        es6: true
      - key: 'then'
        value:
          type: function
          native: duk_bi_promise_then
          length: 2
          varargs: false
        attributes: 'wc'
        es6: true
      # @@toStringTag
      # 'chain' is an obsolete variant of .then and not implemented:
      # https://stackoverflow.com/questions/34713965/the-feature-of-method-promise-prototype-chain-in-chrome

  #
  #  TypedArray
  #

  - id: bi_arraybuffer_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: false
    native: duk_bi_arraybuffer_constructor
    callable: true
    constructable: true
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 1
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_arraybuffer_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "ArrayBuffer"
        attributes: "c"
        es6: true
      - key: "isView"
        value:
          type: function
          native: duk_bi_arraybuffer_isview
          length: 1
          varargs: false
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_arraybuffer_prototype
    class: Object
    internal_prototype: bi_object_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "byteLength"
        value:
          type: accessor
          getter: duk_bi_typedarray_bytelength_getter  # XXX: more lenient than required by spec now
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
      - key: "constructor"
        value:
          type: object
          id: bi_arraybuffer_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "slice"
        value:
          type: function
          native: duk_bi_buffer_slice_shared
          length: 2
          varargs: false
          magic: 2  # magic: 0x01=isView, 0x02=create copy, 0x04=Node.js Buffer special
        typedarray: true
        es6: true

      #- key:  # @@toStringTag
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.toStringTag"
      #  value: XXX
      #  es6: true

  - id: bi_dataview_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: false
    native: duk_bi_dataview_constructor
    callable: true
    constructable: true
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_dataview_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "DataView"
        attributes: "c"
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_dataview_prototype
    class: Object
    internal_prototype: bi_object_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "byteLength"
        value:
          type: accessor
          getter: duk_bi_typedarray_bytelength_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
      - key: "byteOffset"
        value:
          type: accessor
          getter: duk_bi_typedarray_byteoffset_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
      - key: "buffer"
        value:
          type: accessor
          getter: duk_bi_typedarray_buffer_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
      - key: "constructor"
        value:
          type: object
          id: bi_dataview_constructor
        attributes: "wc"
        typedarray: true
        es6: true

      # Int8/Uint8 get/set calls don't have a little endian argument
      # but length/nargs must provide it for the shared helper anyway.

      - key: "getInt8"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "8bit"
            signed: true
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getUint8"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "8bit"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getInt16"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "16bit"
            signed: true
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getUint16"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "16bit"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getInt32"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "32bit"
            signed: true
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getUint32"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "32bit"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getFloat32"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "float"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "getFloat64"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "double"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setInt8"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "8bit"
            signed: true
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setUint8"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "8bit"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setInt16"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "16bit"
            signed: true
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setUint16"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "16bit"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setInt32"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "32bit"
            signed: true
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setUint32"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "32bit"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setFloat32"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "float"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true
      - key: "setFloat64"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "double"
            signed: false
            bigendian: false
            typedarray: true
        typedarray: true
        es6: true

      #- key:  # @@toStringTag
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.toStringTag"
      #  value: XXX
      #  es6: true

  # %TypedArray% constructor
  # Prototype object providing properties shared by all TypedArray
  # constructors.  Callable, but duk_bi_typedarray_constructor()
  # rejects normal calls with TypeError; not constructable which
  # rejects constructor calls with TypeError.
  - id: bi_typedarray_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: false
    nargs: 0
    magic: 0
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 0
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_typedarray_prototype
        attributes: ""
        es6: true
      - key: "name"
        value: "TypedArray"
        attributes: "c"
        es6: true

      # .from
      # .of
      # @@species getter

  # %TypedArrayPrototype%
  # Custom prototype object providing properties shared by all TypedArray
  # instances (reduces built-in object count).  The view specific prototypes
  # (such as Uint8Array.prototype) are still needed so that e.g. instanceof
  # will work properly.

  - id: bi_typedarray_prototype
    class: Object
    internal_prototype: bi_object_prototype
    # no external_prototype (specific views provide it)
    typedarray: true
    es6: true
    bidx: false
    # Present even when DUK_USE_BUFFEROBJECT_SUPPORT is disabled
    # to support plain buffers.

    properties:
      - key: "byteLength"
        value:
          type: accessor
          getter: duk_bi_typedarray_bytelength_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
      - key: "byteOffset"
        value:
          type: accessor
          getter: duk_bi_typedarray_byteoffset_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
      - key: "buffer"
        value:
          type: accessor
          getter: duk_bi_typedarray_buffer_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: ""
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT  # missing without bufferobject support
      - key: "set"
        value:
          type: function
          native: duk_bi_typedarray_set
          length: 2
          varargs: false
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      - key: "subarray"
        value:
          type: function
          native: duk_bi_buffer_slice_shared
          length: 2
          varargs: false
          magic: 1  # magic: 0x01=isView, 0x02=create copy, 0x04=Node.js Buffer special
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT

      #- key:  # @@iterator
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.iterator"
      #  value: XXX
      #  es6: true
      #  present_if: DUK_USE_BUFFEROBJECT_SUPPORT
      #- key:  # @@toStringTag
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.toStringTag"
      #  value: XXX
      #  es6: true
      #  present_if: DUK_USE_BUFFEROBJECT_SUPPORT

  - id: bi_int8array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "int8"
      shift: 0
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_int8array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Int8Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 1
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_int8array_prototype
    internal_prototype: bi_typedarray_prototype
    class: Object
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_int8array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 1
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_uint8array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "uint8"
      shift: 0
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_uint8array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Uint8Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 1
        attributes: ""
        typedarray: true
        es6: true

      # Duktape custom: allocate a plain buffer, return value is always
      # a freshly allocated fixed plain buffer.
      - key: "allocPlain"
        value:
          type: function
          native: duk_bi_uint8array_allocplain
          length: 1
          varargs: false
        duktape: true

      # Duktape custom: get plain buffer underlying a buffer object.
      - key: "plainOf"
        value:
          type: function
          native: duk_bi_uint8array_plainof
          length: 1
          varargs: false
        duktape: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_uint8array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    # Present even when DUK_USE_BUFFEROBJECT_SUPPORT is disabled
    # to support plain buffers.

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_uint8array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
        present_if: DUK_USE_BUFFEROBJECT_SUPPORT  # missing without bufferobject support
      - key: "BYTES_PER_ELEMENT"
        value: 1
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_uint8clampedarray_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "uint8clamped"
      shift: 0
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_uint8clampedarray_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Uint8ClampedArray"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 1
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_uint8clampedarray_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_uint8clampedarray_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 1
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_int16array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "int16"
      shift: 1
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_int16array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Int16Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 2
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_int16array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_int16array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 2
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_uint16array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "uint16"
      shift: 1
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_uint16array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Uint16Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 2
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_uint16array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_uint16array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 2
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_int32array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "int32"
      shift: 2
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_int32array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Int32Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 4
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_int32array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_int32array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 4
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_uint32array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "uint32"
      shift: 2
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_uint32array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Uint32Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 4
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_uint32array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_uint32array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 4
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_float32array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "float32"
      shift: 2
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_float32array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Float32Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 4
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_float32array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_float32array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 4
        attributes: ""
        typedarray: true
        es6: true

  - id: bi_float64array_constructor
    class: Function
    internal_prototype: bi_typedarray_constructor
    varargs: false
    native: duk_bi_typedarray_constructor
    callable: true
    constructable: true
    magic:
      type: typedarray_constructor
      elem: "float64"
      shift: 3
    typedarray: true
    es6: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 3
        attributes: "c"
        typedarray: true
        es6: true
      - key: "prototype"
        value:
          type: object
          id: bi_float64array_prototype
        attributes: ""
        typedarray: true
        es6: true
      - key: "name"
        value: "Float64Array"
        attributes: "c"
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 8
        attributes: ""
        typedarray: true
        es6: true

      #- key:  # @@species
      #    type: symbol
      #    variant: wellknown
      #    string: "Symbol.species"
      #  value: XXX
      #  es6: true

  - id: bi_float64array_prototype
    class: Object
    internal_prototype: bi_typedarray_prototype
    typedarray: true
    es6: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_float64array_constructor
        attributes: "wc"
        typedarray: true
        es6: true
      - key: "BYTES_PER_ELEMENT"
        value: 8
        attributes: ""
        typedarray: true
        es6: true

  #
  #  Node.js Buffer
  #

  - id: bi_nodejs_buffer_constructor
    class: Function
    internal_prototype: bi_function_prototype
    varargs: false
    native: duk_bi_nodejs_buffer_constructor
    callable: true
    constructable: true
    nodejs_buffer: true
    bidx: false
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "length"
        value: 2
        attributes: "c"
        nodejs_buffer: true
      - key: "prototype"
        value:
          type: object
          id: bi_nodejs_buffer_prototype
        attributes: ""
        nodejs_buffer: true
      - key: "name"
        value: "Buffer"
        attributes: "c"
        nodejs_buffer: true

      - key: "concat"
        value:
          type: function
          native: duk_bi_nodejs_buffer_concat
          length: 2
          varargs: false
        nodejs_buffer: true
      - key: "isEncoding"
        value:
          type: function
          native: duk_bi_nodejs_buffer_is_encoding
          length: 1
          varargs:
        nodejs_buffer: true
      - key: "isBuffer"
        value:
          type: function
          native: duk_bi_nodejs_buffer_is_buffer
          length: 1
          varargs: false
        nodejs_buffer: true
      - key: "byteLength"
        value:
          type: function
          native: duk_bi_nodejs_buffer_byte_length
          length: 2
          varargs: false
        nodejs_buffer: true
      - key: "compare"
        value:
          type: function
          native: duk_bi_buffer_compare_shared
          length: 2
          varargs: false
          magic: 3  # magic: 0x02=static call + 0x01=compare = 0x03
        nodejs_buffer: true

  - id: bi_nodejs_buffer_prototype
    internal_prototype: bi_uint8array_prototype
    class: Object
    nodejs_buffer: true
    bidx: true
    present_if: DUK_USE_BUFFEROBJECT_SUPPORT

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_nodejs_buffer_constructor
        attributes: "wc"
        nodejs_buffer: true

      - key: "readUInt8"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "8bit"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readInt8"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "8bit"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readUInt16LE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "16bit"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readUInt16BE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "16bit"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readInt16LE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "16bit"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readInt16BE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "16bit"
            signed: true
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readUInt32LE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "32bit"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readUInt32BE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "32bit"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readInt32LE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "32bit"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readInt32BE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "32bit"
            signed: true
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readFloatLE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "float"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readFloatBE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "float"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readDoubleLE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "double"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readDoubleBE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 2
          varargs: false
          magic:
            type: buffer_readfield
            elem: "double"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readUIntLE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 3
          varargs: false
          magic:
            type: buffer_readfield
            elem: "varint"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readUIntBE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 3
          varargs: false
          magic:
            type: buffer_readfield
            elem: "varint"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "readIntLE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 3
          varargs: false
          magic:
            type: buffer_readfield
            elem: "varint"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "readIntBE"
        value:
          type: function
          native: duk_bi_buffer_readfield
          length: 3
          varargs: false
          magic:
            type: buffer_readfield
            elem: "varint"
            signed: true
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeUInt8"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "8bit"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeInt8"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "8bit"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeUInt16LE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "16bit"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeUInt16BE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "16bit"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeInt16LE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "16bit"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeInt16BE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "16bit"
            signed: true
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeUInt32LE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "32bit"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeUInt32BE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "32bit"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeInt32LE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "32bit"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeInt32BE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "32bit"
            signed: true
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeFloatLE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "float"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeFloatBE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "float"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeDoubleLE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "double"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeDoubleBE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 3
          varargs: false
          magic:
            type: buffer_writefield
            elem: "double"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeUIntLE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 4
          varargs: false
          magic:
            type: buffer_writefield
            elem: "varint"
            signed: false
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeUIntBE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 4
          varargs: false
          magic:
            type: buffer_writefield
            elem: "varint"
            signed: false
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "writeIntLE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 4
          varargs: false
          magic:
            type: buffer_writefield
            elem: "varint"
            signed: true
            bigendian: false
            typedarray: false
        nodejs_buffer: true
      - key: "writeIntBE"
        value:
          type: function
          native: duk_bi_buffer_writefield
          length: 4
          varargs: false
          magic:
            type: buffer_writefield
            elem: "varint"
            signed: true
            bigendian: true
            typedarray: false
        nodejs_buffer: true
      - key: "toString"
        value:
          type: function
          native: duk_bi_nodejs_buffer_tostring
          length: 3
          varargs: false
        nodejs_buffer: true
      - key: "toJSON"
        value:
          type: function
          native: duk_bi_nodejs_buffer_tojson
          length: 0
          varargs: false
        nodejs_buffer: true
      - key: "fill"
        value:
          type: function
          native: duk_bi_nodejs_buffer_fill
          length: 3
          varargs: false
        nodejs_buffer: true
      - key: "equals"
        value:
          type: function
          native: duk_bi_buffer_compare_shared
          length: 1
          varargs: false
          magic: 0  # magic = 0: equals
        nodejs_buffer: true
      - key: "compare"
        value:
          type: function
          native: duk_bi_buffer_compare_shared
          length: 1
          varargs: false
          magic: 1  # magic = 1: compare
        nodejs_buffer: true
      - key: "copy"
        value:
          type: function
          native: duk_bi_nodejs_buffer_copy
          length: 4
          varargs: false
        nodejs_buffer: true
      - key: "slice"
        value:
          type: function
          native: duk_bi_buffer_slice_shared
          length: 2
          varargs: false
          magic: 5  # magic: 0x01=isView, 0x02=create copy, 0x04=Node.js Buffer special
        nodejs_buffer: true
      - key: "write"
        value:
          type: function
          native: duk_bi_nodejs_buffer_write
          length: 4
          varargs: false
        nodejs_buffer: true

  #
  #  Encoding API
  #

  - id: bi_textencoder_constructor
    class: Function
    internal_prototype: bi_function_prototype
    nargs: 0
    native: duk_bi_textencoder_constructor
    callable: true
    constructable: true
    bidx: false
    encoding_api: true
    present_if: DUK_USE_ENCODING_BUILTINS

    properties:
      - key: "length"
        value: 0
        attributes: "c"
        encoding_api: true
      - key: "prototype"
        value:
          type: object
          id: bi_textencoder_prototype
        attributes: ""
        encoding_api: true
      - key: "name"
        value: "TextEncoder"
        attributes: "c"
        encoding_api: true

  - id: bi_textencoder_prototype
    internal_prototype: bi_object_prototype
    class: Object
    bidx: false
    encoding_api: true
    present_if: DUK_USE_ENCODING_BUILTINS

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_textencoder_constructor
        attributes: "wc"
        encoding_api: true
      - key: "encoding"
        value:
          type: accessor
          getter: duk_bi_textencoder_prototype_encoding_getter
          getter_nargs: 0
          getter_magic: 0
        attributes: "ec"
        encoding_api: true
      - key: "encode"
        value:
          type: function
          native: duk_bi_textencoder_prototype_encode
          length: 0
          nargs: 1
        attributes: "wec"
        encoding_api: true

  - id: bi_textdecoder_constructor
    class: Function
    internal_prototype: bi_function_prototype
    nargs: 2
    native: duk_bi_textdecoder_constructor
    callable: true
    constructable: true
    bidx: false
    encoding_api: true
    present_if: DUK_USE_ENCODING_BUILTINS

    properties:
      - key: "length"
        value: 0
        attributes: "c"
        encoding_api: true
      - key: "prototype"
        value:
          type: object
          id: bi_textdecoder_prototype
        attributes: ""
        encoding_api: true
      - key: "name"
        value: "TextDecoder"
        attributes: "c"
        encoding_api: true

  - id: bi_textdecoder_prototype
    internal_prototype: bi_object_prototype
    class: Object
    bidx: false
    encoding_api: true
    present_if: DUK_USE_ENCODING_BUILTINS

    properties:
      - key: "constructor"
        value:
          type: object
          id: bi_textdecoder_constructor
        attributes: "wc"
        encoding_api: true
      - key: "encoding"
        value:
          type: accessor
          getter: duk_bi_textdecoder_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 0  # 0=encoding
        attributes: "ec"
        encoding_api: true
      - key: "fatal"
        value:
          type: accessor
          getter: duk_bi_textdecoder_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 1  # 1=fatal
        attributes: "ec"
        encoding_api: true
      - key: "ignoreBOM"
        value:
          type: accessor
          getter: duk_bi_textdecoder_prototype_shared_getter
          getter_nargs: 0
          getter_magic: 2  # 2=ignoreBOM
        attributes: "ec"
        encoding_api: true
      - key: "decode"
        value:
          type: function
          native: duk_bi_textdecoder_prototype_decode
          length: 0
          nargs: 2
        attributes: "wec"
        encoding_api: true

  - id: bi_performance
    internal_prototype: bi_object_prototype
    class: Object
    bidx: false
    performance_api: true
    present_if: DUK_USE_PERFORMANCE_BUILTIN

    properties:
      # Firefox and Chrome: data property with 'wec' attributes,
      # inherited from PerformancePrototype.  Use own data property
      # for now.
      # XXX: we'd like to use 'wec' but current built-in init data doesn't
      # support it; use 'wc' for consistency so ROM built-ins have the same
      # behavior.
      - key: "now"
        value:
          type: function
          native: duk_bi_performance_now
          length: 0
          nargs: 0
        attributes: "wc"
        performance_api: true
      # Missing until semantics decided.
      #- key: "timeOrigin"
      #  value:
      #    type: accessor
      #    getter: duk_bi_performance_timeorigin_getter
      #    getter_nargs: 0
      #    getter_magic: 0
      #  attributes: "ec"  # check
      #  performance_api: true