LibJS: Update DurationFormat AO text to align with ECMA-402 and Temporal

These are editorial changes in the Intl.DurationFormat proposal. See:
71b291b
d0cc6fa
d4b35bb

Userland/Libraries/LibJS/Runtime/Intl/DurationFormat.cpp

@@ -145,7 +145,7 @@ ThrowCompletionOr<Temporal::DurationRecord> to_duration_record(VM& vm, Value inp
     // 3. Let any be false.
     auto any = false;
 
-    // 4. For each row in Table 1, except the header row, in table order, do
+    // 4. For each row of Table 1, except the header row, in table order, do
     for (auto const& duration_instances_component : duration_instances_components) {
         // a. Let valueSlot be the Value Slot value of the current row.
         auto value_slot = duration_instances_component.value_slot;
@@ -180,12 +180,12 @@ ThrowCompletionOr<Temporal::DurationRecord> to_duration_record(VM& vm, Value inp
 // 1.1.4 DurationRecordSign ( record ), https://tc39.es/proposal-intl-duration-format/#sec-durationrecordsign
 i8 duration_record_sign(Temporal::DurationRecord const& record)
 {
-    // 1. For each row in Table 1, except the header row, in table order, do
+    // 1. For each row of Table 1, except the header row, in table order, do
     for (auto const& duration_instances_component : duration_instances_components) {
-        // a. Let valueSlot be the Value Slot value.
+        // a. Let valueSlot be the Value Slot value of the current row.
         auto value_slot = duration_instances_component.value_slot;
 
-        // b. Let v be value of the valueSlot slot of record.
+        // b. Let v be record.[[<valueSlot>]].
         auto value = record.*value_slot;
 
         // c. If v < 0, return -1.
@@ -207,17 +207,16 @@ bool is_valid_duration_record(Temporal::DurationRecord const& record)
     // 1. Let sign be ! DurationRecordSign(record).
     auto sign = duration_record_sign(record);
 
-    // 2. For each row in Table 1, except the header row, in table order, do
+    // 2. For each row of Table 1, except the header row, in table order, do
     for (auto const& duration_instances_component : duration_instances_components) {
-        // a. Let valueSlot be the Value Slot value.
+        // a. Let valueSlot be the Value Slot value of the current row.
         auto value_slot = duration_instances_component.value_slot;
 
-        // b. Let v be value of the valueSlot slot of record.
+        // b. Let v be record.[[<valueSlot>]].
         auto value = record.*value_slot;
 
-        // c. If 𝔽(v) is not finite, return false.
-        if (!isfinite(value))
-            return false;
+        // c. Assert: 𝔽(v) is finite.
+        VERIFY(isfinite(value));
 
         // d. If v < 0 and sign > 0, return false.
         if (value < 0 && sign > 0)

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatConstructor.cpp

@@ -101,12 +101,12 @@ ThrowCompletionOr<Object*> DurationFormatConstructor::construct(FunctionObject&
     // 16. Let prevStyle be the empty String.
     auto previous_style = String::empty();
 
-    // 17. For each row in Table 1, except the header row, in table order, do
+    // 17. For each row of Table 1, except the header row, in table order, do
     for (auto const& duration_instances_component : duration_instances_components) {
-        // a. Let styleSlot be the Style Slot value.
+        // a. Let styleSlot be the Style Slot value of the current row.
         auto style_slot = duration_instances_component.set_style_slot;
 
-        // b. Let displaySlot be the Display Slot value.
+        // b. Let displaySlot be the Display Slot value of the current row.
         auto display_slot = duration_instances_component.set_display_slot;
 
         // c. Let unit be the Unit value.

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatPrototype.cpp

@@ -46,14 +46,14 @@ JS_DEFINE_NATIVE_FUNCTION(DurationFormatPrototype::format)
     if (!is_valid_duration_record(record))
         return vm.throw_completion<RangeError>(ErrorType::TemporalInvalidDurationLikeObject);
 
-    // 5. Let formatted be ! PartitionDurationFormatPattern(df, record).
-    auto formatted = partition_duration_format_pattern(vm, *duration_format, record);
+    // 5. Let parts be ! PartitionDurationFormatPattern(df, record).
+    auto parts = partition_duration_format_pattern(vm, *duration_format, record);
 
     // 6. Let result be a new empty String.
     StringBuilder result;
 
-    // 7. For each element part in formatted, in List order, do
-    for (auto const& part : formatted) {
+    // 7. For each Record { [[Type]], [[Value]] } part in parts, do
+    for (auto const& part : parts) {
         // a. Set result to the string-concatenation of result and part.[[Value]].
         result.append(part.value);
     }
@@ -78,16 +78,16 @@ JS_DEFINE_NATIVE_FUNCTION(DurationFormatPrototype::format_to_parts)
     if (!is_valid_duration_record(record))
         return vm.throw_completion<RangeError>(ErrorType::TemporalInvalidDurationLikeObject);
 
-    // 5. Let formatted be ! PartitionDurationFormatPattern(df, record).
-    auto formatted = partition_duration_format_pattern(vm, *duration_format, record);
+    // 5. Let parts be ! PartitionDurationFormatPattern(df, record).
+    auto parts = partition_duration_format_pattern(vm, *duration_format, record);
 
     // 6. Let result be ! ArrayCreate(0).
     auto* result = MUST(Array::create(realm, 0));
 
     // 7. Let n be 0.
-    // 8. For each element part in formatted, in List order, do
-    for (size_t n = 0; n < formatted.size(); ++n) {
-        auto const& part = formatted[n];
+    // 8. For each { [[Type]], [[Value]] } part in parts, do
+    for (size_t n = 0; n < parts.size(); ++n) {
+        auto const& part = parts[n];
 
         // a. Let obj be ! OrdinaryObjectCreate(%ObjectPrototype%).
         auto* object = Object::create(realm, realm.intrinsics().object_prototype());