Normative: Integrate Intl NumberFormat v3 into ECMA-402 (tc39#753)

spec/negotiation.html

@@ -85,7 +85,7 @@ <h1>BestAvailableLocale ( _availableLocales_, _locale_ )</h1>
       <emu-alg>
         1. Let _candidate_ be _locale_.
         1. Repeat,
-          1. If _availableLocales_ contains an element equal to _candidate_, return _candidate_.
+          1. If _availableLocales_ contains _candidate_, return _candidate_.
           1. Let _pos_ be the character index of the last occurrence of *"-"* (U+002D) within _candidate_. If that character does not occur, return *undefined*.
           1. If _pos_ &ge; 2 and the character *"-"* occurs at index _pos_ - 2 of candidate, decrease _pos_ by 2.
           1. Let _candidate_ be the substring of _candidate_ from position 0, inclusive, to position _pos_, exclusive.
@@ -353,7 +353,31 @@ <h1>
         1. Else,
           1. Assert: _type_ is ~string~.
           1. Set _value_ to ? ToString(_value_).
-        1. If _values_ is not ~empty~ and _values_ does not contain an element equal to _value_, throw a *RangeError* exception.
+        1. If _values_ is not ~empty~ and _values_ does not contain _value_, throw a *RangeError* exception.
+        1. Return _value_.
+      </emu-alg>
+    </emu-clause>
+
+    <emu-clause id="sec-getbooleanorstringnumberformatoption" type="abstract operation">
+      <h1>
+        GetBooleanOrStringNumberFormatOption (
+          _options_: an Object,
+          _property_: a property key,
+          _stringValues_: a List of Strings,
+          _fallback_: an ECMAScript language value,
+        ): either a normal completion containing either a Boolean, String, or _fallback_, or a throw completion
+      </h1>
+      <dl class="header">
+        <dt>description</dt>
+        <dd>It extracts the value of the property named _property_ from the provided _options_ object. It returns _fallback_ if that value is *undefined*, *true* if that value is *true*, *false* if that value coerces to *false*, and otherwise coerces it to a String and returns the result if it is allowed by _stringValues_.</dd>
+      </dl>
+      <emu-alg>
+        1. Let _value_ be ? Get(_options_, _property_).
+        1. If _value_ is *undefined*, return _fallback_.
+        1. If _value_ is *true*, return *true*.
+        1. If ToBoolean(_value_) is *false*, return *false*.
+        1. Let _value_ be ? ToString(_value_).
+        1. If _stringValues_ does not contain _value_, throw a *RangeError* exception.
         1. Return _value_.
       </emu-alg>
     </emu-clause>