Tidy up macToQtFormat() in Darwin system locale backend

Impose standard Qt indent.
Within each set of cases grouped together, impose alphabetic order.
Made formatting of ranges in comments terser, for two-value ranges.
Fix errors:
* the 'j' field should not arise and has a 'J' partner
* The 'c', 'e' and 'E' forms' numeric variants are still day of the
  week, so should not be mapped to 'd' or 'dd', which are day of the
  month. Qt date formats only actually support long and short, not
  narrow, despite the QLocale::Format having a NarrowFormat.

Other errors and infelicities shall be addressed in later work, in
tandem with changes to dateconverter.py that are coming.

Task-number: QTBUG-123872
Change-Id: I61bf363d2598502f8bfc0d67245eae1b41858147
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 86 insertions, 89 deletions

diff --git a/src/corelib/text/qlocale_mac.mm b/src/corelib/text/qlocale_mac.mm
index ed4399e6a3..a1a19b5f33 100644
--- a/src/corelib/text/qlocale_mac.mm
+++ b/src/corelib/text/qlocale_mac.mm
@@ -323,99 +323,96 @@ static QVariant macToQtFormat(QStringView sys_fmt)
         }
 
         QChar c = sys_fmt.at(i);
-        qsizetype repeat = qt_repeatCount(sys_fmt.mid(i));
+        qsizetype repeat = qt_repeatCount(sys_fmt.sliced(i));
 
         switch (c.unicode()) {
             // Qt does not support the following options
-            case 'G': // Era (1..5): 4 = long, 1..3 = short, 5 = narrow
-            case 'Y': // Year of Week (1..n): 1..n = padded number
-            case 'U': // Cyclic Year Name (1..5): 4 = long, 1..3 = short, 5 = narrow
-            case 'Q': // Quarter (1..4): 4 = long, 3 = short, 1..2 = padded number
-            case 'q': // Standalone Quarter (1..4): 4 = long, 3 = short, 1..2 = padded number
-            case 'w': // Week of Year (1..2): 1..2 = padded number
-            case 'W': // Week of Month (1): 1 = number
-            case 'D': // Day of Year (1..3): 1..3 = padded number
-            case 'F': // Day of Week in Month (1): 1 = number
-            case 'g': // Modified Julian Day (1..n): 1..n = padded number
-            case 'A': // Milliseconds in Day (1..n): 1..n = padded number
-                break;
-
-            case 'y': // Year (1..n): 2 = short year, 1 & 3..n = padded number
-            case 'u': // Extended Year (1..n): 2 = short year, 1 & 3..n = padded number
-                // Qt only supports long (4) or short (2) year, use long for all others
-                if (repeat == 2)
-                    result += "yy"_L1;
-                else
-                    result += "yyyy"_L1;
-                break;
-            case 'M': // Month (1..5): 4 = long, 3 = short, 1..2 = number, 5 = narrow
-            case 'L': // Standalone Month (1..5): 4 = long, 3 = short, 1..2 = number, 5 = narrow
-                // Qt only supports long, short and number, use short for narrow
-                if (repeat == 5)
-                    result += "MMM"_L1;
-                else
-                    result += QString(repeat, u'M');
-                break;
-            case 'd': // Day of Month (1..2): 1..2 padded number
-                result += QString(repeat, c);
-                break;
-            case 'E': // Day of Week (1..6): 4 = long, 1..3 = short, 5..6 = narrow
-                // Qt only supports long, short and padded number, use short for narrow
-                if (repeat == 4)
-                    result += "dddd"_L1;
-                else
-                    result += "ddd"_L1;
-                break;
-            case 'e': // Local Day of Week (1..6): 4 = long, 3 = short, 5..6 = narrow, 1..2 padded number
-            case 'c': // Standalone Local Day of Week (1..6): 4 = long, 3 = short, 5..6 = narrow, 1..2 padded number
-                // Qt only supports long, short and padded number, use short for narrow
-                if (repeat >= 5)
-                    result += "ddd"_L1;
-                else
-                    result += QString(repeat, 'd'_L1);
-                break;
-            case 'a': // AM/PM (1): 1 = short
-                // Translate to Qt uppercase AM/PM
-                result += "AP"_L1;
-                break;
-            case 'h': // Hour [1..12] (1..2): 1..2 = padded number
-            case 'K': // Hour [0..11] (1..2): 1..2 = padded number
-            case 'j': // Local Hour [12 or 24] (1..2): 1..2 = padded number
-                // Qt h is local hour
-                result += QString(repeat, 'h'_L1);
-                break;
-            case 'H': // Hour [0..23] (1..2): 1..2 = padded number
-            case 'k': // Hour [1..24] (1..2): 1..2 = padded number
-                // Qt H is 0..23 hour
-                result += QString(repeat, 'H'_L1);
-                break;
-            case 'm': // Minutes (1..2): 1..2 = padded number
-            case 's': // Seconds (1..2): 1..2 = padded number
+        case 'A': // Milliseconds in Day (1..n): 1..n = padded number
+        case 'C': // Input skeleton symbol.
+        case 'D': // Day of Year (1..3): 1..3 = padded number
+        case 'F': // Day of Week in Month (1): 1 = number
+        case 'g': // Modified Julian Day (1..n): 1..n = padded number
+        case 'G': // Era (1..5): 4 = long, 1..3 = short, 5 = narrow
+        case 'j': // Input skeleton symbol.
+        case 'J': // Input skeleton symbol.
+        case 'l': // Deprecated Chinese leap month indicator.
+        case 'q': // Standalone Quarter (1..4): 4 = long, 3 = short, 1,2 = padded number
+        case 'Q': // Quarter (1..4): 4 = long, 3 = short, 1,2 = padded number
+        case 'U': // Cyclic Year Name (1..5): 4 = long, 1..3 = short, 5 = narrow
+        case 'w': // Week of Year (1,2): 1,2 = padded number
+        case 'W': // Week of Month (1): 1 = number
+        case 'Y': // Year for Week-of-year calendars (1..n): 1..n = padded number
+            break;
+
+        case 'u': // Extended Year (1..n): 2 = short year, 1 & 3..n = padded number
+        case 'y': // Year (1..n): 2 = short year, 1 & 3..n = padded number
+            // Qt only supports long (4) or short (2) year, use long for all others
+            if (repeat == 2)
+                result += "yy"_L1;
+            else
+                result += "yyyy"_L1;
+            break;
+        case 'L': // Standalone Month (1..5): 4 = long, 3 = short, 1,2 = number, 5 = narrow
+        case 'M': // Month (1..5): 4 = long, 3 = short, 1,2 = number, 5 = narrow
+            // Qt only supports long, short and number, use short for narrow
+            if (repeat == 5)
+                result += "MMM"_L1;
+            else
+                result += QString(repeat, u'M');
+            break;
+        case 'd': // Day of Month (1,2): 1,2 padded number
+            result += QString(repeat, c);
+            break;
+        case 'c': // Standalone version of 'e'
+        case 'e': // Local Day of Week (1..6): 4 = long, 3 = short, 5,6 = narrow, 1,2 padded number
+            // "Local" only affects numeric form: depends on locale's start-day of the week.
+        case 'E': // Day of Week (1..6): 4 = long, 1..3 = short, 5,6 = narrow
+            // Qt only supports long, short: use short for narrow and padded number.
+            if (repeat == 4)
+                result += "dddd"_L1;
+            else
+                result += "ddd"_L1;
+            break;
+        case 'a': // AM/PM (1): 1 = short
+            // Translate to Qt uppercase AM/PM
+            result += "AP"_L1;
+            break;
+        case 'h': // Hour [1..12] (1,2): 1,2 = padded number
+        case 'K': // Hour [0..11] (1,2): 1,2 = padded number
+            result += QString(repeat, 'h'_L1);
+            break;
+        case 'H': // Hour [0..23] (1,2): 1,2 = padded number
+        case 'k': // Hour [1..24] (1,2): 1,2 = padded number
+            // Qt H is 0..23 hour
+            result += QString(repeat, 'H'_L1);
+            break;
+        case 'm': // Minutes (1,2): 1,2 = padded number
+        case 's': // Seconds (1,2): 1,2 = padded number
+            result += QString(repeat, c);
+            break;
+        case 'S': // Fractional second (1..n): 1..n = truncates to decimal places
+            // Qt uses msecs either unpadded or padded to 3 places
+            if (repeat < 3)
+                result += u'z';
+            else
+                result += "zzz"_L1;
+            break;
+        case 'O': // Time Zone (1, 4)
+        case 'v': // Time Zone (1, 4)
+        case 'V': // Time Zone (1..4)
+        case 'x': // Time Zone (1..5)
+        case 'X': // Time Zone (1..5)
+        case 'z': // Time Zone (1..4)
+        case 'Z': // Time Zone (1..5)
+            result += u't';
+            break;
+        default:
+            // a..z and A..Z are reserved for format codes, so any occurrence of these not
+            // already processed are not known and so unsupported formats to be ignored.
+            // All other chars are allowed as literals.
+            if (c < u'A' || c > u'z' || (c > u'Z' && c < u'a'))
                 result += QString(repeat, c);
-                break;
-            case 'S': // Fractional second (1..n): 1..n = truncates to decimal places
-                // Qt uses msecs either unpadded or padded to 3 places
-                if (repeat < 3)
-                    result += u'z';
-                else
-                    result += "zzz"_L1;
-                break;
-            case 'z': // Time Zone (1..4)
-            case 'Z': // Time Zone (1..5)
-            case 'O': // Time Zone (1, 4)
-            case 'v': // Time Zone (1, 4)
-            case 'V': // Time Zone (1..4)
-            case 'X': // Time Zone (1..5)
-            case 'x': // Time Zone (1..5)
-                result += u't';
-                break;
-            default:
-                // a..z and A..Z are reserved for format codes, so any occurrence of these not
-                // already processed are not known and so unsupported formats to be ignored.
-                // All other chars are allowed as literals.
-                if (c < u'A' || c > u'z' || (c > u'Z' && c < u'a'))
-                    result += QString(repeat, c);
-                break;
+            break;
         }
 
         i += repeat;