LibJS: Update spec comments to use ToZeroPaddedDecimalString AO

This is an editorial change in the ECMA-262 and Temporal specs.

See:
- https://github.com/tc39/ecma262/commit/843d8b8
- https://github.com/tc39/proposal-temporal/commit/f9211d9

Note that we don't actually need to implement the AO as we already have
String::formatted() for this, and use unified format strings instead of
zero-padding in individual steps in many cases anyway.

Userland/Libraries/LibJS/Runtime/DatePrototype.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2020-2022, Linus Groh <linusg@serenityos.org>
  * Copyright (c) 2021, Petróczi Zoltán <petroczizoltan@tutanota.com>
  * Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
  * Copyright (c) 2022, Tim Flynn <trflynn89@serenityos.org>
@@ -1084,13 +1084,13 @@ JS_DEFINE_NATIVE_FUNCTION(DatePrototype::to_string)
 // 21.4.4.41.1 TimeString ( tv ), https://tc39.es/ecma262/#sec-timestring
 String time_string(double time)
 {
-    // 1. Let hour be the String representation of HourFromTime(tv), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 1. Let hour be ToZeroPaddedDecimalString(ℝ(HourFromTime(tv)), 2).
     auto hour = hour_from_time(time);
 
-    // 2. Let minute be the String representation of MinFromTime(tv), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 2. Let minute be ToZeroPaddedDecimalString(ℝ(MinFromTime(tv)), 2).
     auto minute = min_from_time(time);
 
-    // 3. Let second be the String representation of SecFromTime(tv), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 3. Let second be ToZeroPaddedDecimalString(ℝ(SecFromTime(tv)), 2).
     auto second = sec_from_time(time);
 
     // 4. Return the string-concatenation of hour, ":", minute, ":", second, the code unit 0x0020 (SPACE), and "GMT".
@@ -1106,7 +1106,7 @@ String date_string(double time)
     // 2. Let month be the Name of the entry in Table 63 with the Number MonthFromTime(tv).
     auto month = short_month_names[month_from_time(time)];
 
-    // 3. Let day be the String representation of DateFromTime(tv), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 3. Let day be ToZeroPaddedDecimalString(ℝ(DateFromTime(tv)), 2).
     auto day = date_from_time(time);
 
     // 4. Let yv be YearFromTime(tv).
@@ -1115,12 +1115,9 @@ String date_string(double time)
     // 5. If yv ≥ +0𝔽, let yearSign be the empty String; otherwise, let yearSign be "-".
     auto year_sign = year >= 0 ? ""sv : "-"sv;
 
-    // 6. Let year be the String representation of abs(ℝ(yv)), formatted as a decimal number.
-    year = abs(year);
-
-    // 7. Let paddedYear be ! StringPad(year, 4𝔽, "0", start).
-    // 8. Return the string-concatenation of weekday, the code unit 0x0020 (SPACE), month, the code unit 0x0020 (SPACE), day, the code unit 0x0020 (SPACE), yearSign, and paddedYear.
-    return String::formatted("{} {} {:02} {}{:04}", weekday, month, day, year_sign, year);
+    // 6. Let paddedYear be ToZeroPaddedDecimalString(abs(ℝ(yv)), 4).
+    // 7. Return the string-concatenation of weekday, the code unit 0x0020 (SPACE), month, the code unit 0x0020 (SPACE), day, the code unit 0x0020 (SPACE), yearSign, and paddedYear.
+    return String::formatted("{} {} {:02} {}{:04}", weekday, month, day, year_sign, abs(year));
 }
 
 // 21.4.4.41.3 TimeZoneString ( tv ), https://tc39.es/ecma262/#sec-timezoneestring
@@ -1145,10 +1142,10 @@ String time_zone_string(double time)
         offset *= -1;
     }
 
-    // 4. Let offsetMin be the String representation of MinFromTime(absOffset), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 4. Let offsetMin be ToZeroPaddedDecimalString(ℝ(MinFromTime(absOffset)), 2).
     auto offset_min = min_from_time(offset);
 
-    // 5. Let offsetHour be the String representation of HourFromTime(absOffset), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 5. Let offsetHour be ToZeroPaddedDecimalString(ℝ(HourFromTime(absOffset)), 2).
     auto offset_hour = hour_from_time(offset);
 
     // 6. Let tzName be an implementation-defined string that is either the empty String or the string-concatenation of the code unit 0x0020 (SPACE), the code unit 0x0028 (LEFT PARENTHESIS), an implementation-defined timezone name, and the code unit 0x0029 (RIGHT PARENTHESIS).
@@ -1226,7 +1223,7 @@ JS_DEFINE_NATIVE_FUNCTION(DatePrototype::to_utc_string)
     // 5. Let month be the Name of the entry in Table 63 with the Number MonthFromTime(tv).
     auto month = short_month_names[month_from_time(time.as_double())];
 
-    // 6. Let day be the String representation of DateFromTime(tv), formatted as a two-digit decimal number, padded to the left with the code unit 0x0030 (DIGIT ZERO) if necessary.
+    // 6. Let day be ToZeroPaddedDecimalString(ℝ(DateFromTime(tv)), 2).
     auto day = date_from_time(time.as_double());
 
     // 7. Let yv be YearFromTime(tv).
@@ -1235,12 +1232,9 @@ JS_DEFINE_NATIVE_FUNCTION(DatePrototype::to_utc_string)
     // 8. If yv ≥ +0𝔽, let yearSign be the empty String; otherwise, let yearSign be "-".
     auto year_sign = year >= 0 ? ""sv : "-"sv;
 
-    // 9. Let year be the String representation of abs(ℝ(yv)), formatted as a decimal number.
-    year = abs(year);
-
-    // 10. Let paddedYear be ! StringPad(year, 4𝔽, "0", start).
-    // 11. Return the string-concatenation of weekday, ",", the code unit 0x0020 (SPACE), day, the code unit 0x0020 (SPACE), month, the code unit 0x0020 (SPACE), yearSign, paddedYear, the code unit 0x0020 (SPACE), and TimeString(tv).
-    auto string = String::formatted("{}, {:02} {} {}{:04} {}", weekday, day, month, year_sign, year, time_string(time.as_double()));
+    // 9. Let paddedYear be ToZeroPaddedDecimalString(abs(ℝ(yv)), 4).
+    // 10. Return the string-concatenation of weekday, ",", the code unit 0x0020 (SPACE), day, the code unit 0x0020 (SPACE), month, the code unit 0x0020 (SPACE), yearSign, paddedYear, the code unit 0x0020 (SPACE), and TimeString(tv).
+    auto string = String::formatted("{}, {:02} {} {}{:04} {}", weekday, day, month, year_sign, abs(year), time_string(time.as_double()));
     return js_string(vm, move(string));
 }
 

Userland/Libraries/LibJS/Runtime/Temporal/AbstractOperations.cpp

@@ -941,7 +941,7 @@ String format_seconds_string_part(u8 second, u16 millisecond, u16 microsecond, u
     if (precision.has<StringView>() && precision.get<StringView>() == "minute"sv)
         return String::empty();
 
-    // 3. Let secondsString be the string-concatenation of the code unit 0x003A (COLON) and second formatted as a two-digit decimal number, padded to the left with zeroes if necessary.
+    // 3. Let secondsString be the string-concatenation of the code unit 0x003A (COLON) and ToZeroPaddedDecimalString(second, 2).
     auto seconds_string = String::formatted(":{:02}", second);
 
     // 4. Let fraction be millisecond × 10^6 + microsecond × 10^3 + nanosecond.
@@ -955,7 +955,7 @@ String format_seconds_string_part(u8 second, u16 millisecond, u16 microsecond, u
         if (fraction == 0)
             return seconds_string;
 
-        // b. Set fraction to fraction formatted as a nine-digit decimal number, padded to the left with zeroes if necessary.
+        // b. Set fraction to ToZeroPaddedDecimalString(fraction, 9).
         fraction_string = String::formatted("{:09}", fraction);
 
         // c. Set fraction to the longest possible substring of fraction starting at position 0 and not ending with the code unit 0x0030 (DIGIT ZERO).
@@ -967,7 +967,7 @@ String format_seconds_string_part(u8 second, u16 millisecond, u16 microsecond, u
         if (precision.get<u8>() == 0)
             return seconds_string;
 
-        // b. Set fraction to fraction formatted as a nine-digit decimal number, padded to the left with zeroes if necessary.
+        // b. Set fraction to ToZeroPaddedDecimalString(fraction, 9)
         fraction_string = String::formatted("{:09}", fraction);
 
         // c. Set fraction to the substring of fraction from 0 to precision.

Userland/Libraries/LibJS/Runtime/Temporal/Calendar.cpp

@@ -723,6 +723,8 @@ u8 to_iso_week_of_year(i32 year, u8 month, u8 day)
 // 12.1.36 BuildISOMonthCode ( month ), https://tc39.es/proposal-temporal/#sec-buildisomonthcode
 String build_iso_month_code(u8 month)
 {
+    // 1. Let numberPart be ToZeroPaddedDecimalString(month, 2).
+    // 2. Return the string-concatenation of "M" and numberPart.
     return String::formatted("M{:02}", month);
 }
 

Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp

@@ -1661,7 +1661,7 @@ String temporal_duration_to_string(double years, double months, double weeks, do
         // a. Let fraction be abs(milliseconds) × 10^6 + abs(microseconds) × 10^3 + abs(nanoseconds).
         auto fraction = fabs(milliseconds) * 1'000'000 + fabs(microseconds) * 1'000 + fabs(nanoseconds);
 
-        // b. Let decimalPart be fraction formatted as a nine-digit decimal number, padded to the left with zeroes if necessary.
+        // b. Let decimalPart be ToZeroPaddedDecimalString(fraction, 9).
         // NOTE: padding with zeros leads to weird results when applied to a double. Not sure if that's a bug in AK/Format.h or if I'm doing this wrong.
         auto decimal_part = String::formatted("{:09}", (u64)fraction);
 

Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.cpp

@@ -498,14 +498,14 @@ String pad_iso_year(i32 y)
 
     // 2. If y ≥ 0 and y ≤ 9999, then
     if (y >= 0 && y <= 9999) {
-        // a. Return y formatted as a four-digit decimal number, padded to the left with zeroes as necessary.
+        // a. Return ToZeroPaddedDecimalString(y, 4).
         return String::formatted("{:04}", y);
     }
 
     // 3. If y > 0, let yearSign be "+"; otherwise, let yearSign be "-".
     auto year_sign = y > 0 ? '+' : '-';
 
-    // 4. Let year be abs(y), formatted as a six-digit decimal number, padded to the left with zeroes as necessary.
+    // 4. Let year be ToZeroPaddedDecimalString(abs(y), 6).
     // 5. Return the string-concatenation of yearSign and year.
     return String::formatted("{}{:06}", year_sign, abs(y));
 }
@@ -519,10 +519,10 @@ ThrowCompletionOr<String> temporal_date_to_string(GlobalObject& global_object, P
     // 3. Let year be ! PadISOYear(temporalDate.[[ISOYear]]).
     auto year = pad_iso_year(temporal_date.iso_year());
 
-    // 4. Let month be temporalDate.[[ISOMonth]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 4. Let month be ToZeroPaddedDecimalString(monthDay.[[ISOMonth]], 2).
     auto month = String::formatted("{:02}", temporal_date.iso_month());
 
-    // 5. Let day be temporalDate.[[ISODay]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 5. Let day be ToZeroPaddedDecimalString(monthDay.[[ISODay]], 2).
     auto day = String::formatted("{:02}", temporal_date.iso_day());
 
     // 6. Let calendarID be ? ToString(temporalDate.[[Calendar]]).

Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp

@@ -275,10 +275,10 @@ ThrowCompletionOr<String> temporal_date_time_to_string(GlobalObject& global_obje
     // 1. Assert: isoYear, isoMonth, isoDay, hour, minute, second, millisecond, microsecond, and nanosecond are integers.
 
     // 2. Let year be ! PadISOYear(isoYear).
-    // 3. Let month be isoMonth formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // 4. Let day be isoDay formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // 5. Let hour be hour formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // 6. Let minute be minute formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 3. Let month be ToZeroPaddedDecimalString(isoMonth, 2).
+    // 4. Let day be ToZeroPaddedDecimalString(isoDay, 2).
+    // 5. Let hour be ToZeroPaddedDecimalString(hour, 2).
+    // 6. Let minute be ToZeroPaddedDecimalString(minute, 2).
 
     // 7. Let seconds be ! FormatSecondsStringPart(second, millisecond, microsecond, nanosecond, precision).
     auto seconds = format_seconds_string_part(second, millisecond, microsecond, nanosecond, precision);

Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp

@@ -176,8 +176,8 @@ ThrowCompletionOr<String> temporal_month_day_to_string(GlobalObject& global_obje
     // 1. Assert: Type(monthDay) is Object.
     // 2. Assert: monthDay has an [[InitializedTemporalMonthDay]] internal slot.
 
-    // 3. Let month be monthDay.[[ISOMonth]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // 4. Let day be monthDay.[[ISODay]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 3. Let month be ToZeroPaddedDecimalString(temporalDate.[[ISOMonth]], 2).
+    // 4. Let day be ToZeroPaddedDecimalString(temporalDate.[[ISODay]], 2).
     // 5. Let result be the string-concatenation of month, the code unit 0x002D (HYPHEN-MINUS), and day.
     auto result = String::formatted("{:02}-{:02}", month_day.iso_month(), month_day.iso_day());
 

Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.cpp

@@ -427,8 +427,8 @@ String temporal_time_to_string(u8 hour, u8 minute, u8 second, u16 millisecond, u
 {
     // 1. Assert: hour, minute, second, millisecond, microsecond and nanosecond are integers.
 
-    // 2. Let hour be hour formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // 3. Let minute be minute formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 2. Let hour be ToZeroPaddedDecimalString(hour, 2).
+    // 3. Let minute be ToZeroPaddedDecimalString(minute, 2).
 
     // 4. Let seconds be ! FormatSecondsStringPart(second, millisecond, microsecond, nanosecond, precision).
     auto seconds = format_seconds_string_part(second, millisecond, microsecond, nanosecond, precision);

Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonth.cpp

@@ -233,7 +233,7 @@ ThrowCompletionOr<String> temporal_year_month_to_string(GlobalObject& global_obj
     // 2. Assert: yearMonth has an [[InitializedTemporalYearMonth]] internal slot.
 
     // 3. Let year be ! PadISOYear(yearMonth.[[ISOYear]]).
-    // 4. Let month be yearMonth.[[ISOMonth]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 4. Let month be ToZeroPaddedDecimalString(yearMonth.[[ISOMonth]], 2).
     // 5. Let result be the string-concatenation of year, the code unit 0x002D (HYPHEN-MINUS), and month.
     auto result = String::formatted("{}-{:02}", pad_iso_year(year_month.iso_year()), year_month.iso_month());
 
@@ -242,7 +242,7 @@ ThrowCompletionOr<String> temporal_year_month_to_string(GlobalObject& global_obj
 
     // 7. If showCalendar is "always" or if calendarID is not "iso8601", then
     if (show_calendar == "always"sv || calendar_id != "iso8601") {
-        // a. Let day be yearMonth.[[ISODay]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+        // a. Let day be ToZeroPaddedDecimalString(yearMonth.[[ISODay]], 2).
         // b. Set result to the string-concatenation of result, the code unit 0x002D (HYPHEN-MINUS), and day.
         result = String::formatted("{}-{:02}", result, year_month.iso_day());
     }

Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp

@@ -344,16 +344,16 @@ String format_time_zone_offset_string(double offset_nanoseconds)
     // 7. Let hours be floor(offsetNanoseconds / (3.6 × 10^12)).
     auto hours = offset / 3600000000000;
 
-    // 8. Let h be hours, formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 8. Let h be ToZeroPaddedDecimalString(hours, 2).
     builder.appendff("{:02}", hours);
-    // 9. Let m be minutes, formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 9. Let m be ToZeroPaddedDecimalString(minutes, 2).
     builder.appendff(":{:02}", minutes);
-    // 10. Let s be seconds, formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // Handled by steps 10 & 11
+    // 10. Let s be ToZeroPaddedDecimalString(seconds, 2).
+    // NOTE: Handled by steps 11 & 12
 
     // 11. If nanoseconds ≠ 0, then
     if (nanoseconds != 0) {
-        // a. Let fraction be nanoseconds, formatted as a nine-digit decimal number, padded to the left with zeroes if necessary.
+        // a. Let fraction be ToZeroPaddedDecimalString(nanoseconds, 9).
         // b. Set fraction to the longest possible substring of fraction starting at position 0 and not ending with the code unit 0x0030 (DIGIT ZERO).
         // c. Let post be the string-concatenation of the code unit 0x003A (COLON), s, the code unit 0x002E (FULL STOP), and fraction.
         builder.appendff(":{:02}.{}", seconds, String::formatted("{:09}", nanoseconds).trim("0"sv, TrimMode::Right));
@@ -391,8 +391,8 @@ String format_iso_time_zone_offset_string(double offset_nanoseconds)
     // 6. Let hours be floor(offsetNanoseconds / (3600 × 10^9)).
     auto hours = floor(offset_nanoseconds / 3600000000000);
 
-    // 7. Let h be hours, formatted as a two-digit decimal number, padded to the left with a zero if necessary.
-    // 8. Let m be minutes, formatted as a two-digit decimal number, padded to the left with a zero if necessary.
+    // 7. Let h be ToZeroPaddedDecimalString(hours, 2).
+    // 8. Let m be ToZeroPaddedDecimalString(minutes, 2).
     // 9. Return the string-concatenation of sign, h, the code unit 0x003A (COLON), and m.
     return String::formatted("{}{:02}:{:02}", sign, (u32)hours, (u32)minutes);
 }