feat: drop the neutral kind behavior

Author: hejsztynx

ios/inputAttributesManager/InputAttributesManager.mm

@@ -114,8 +114,9 @@ - (void)handleDirtyRangesStyling {
                      [self stylingOrderFor:_input->stylesDict[a]];
                  NSInteger bOrder =
                      [self stylingOrderFor:_input->stylesDict[b]];
-                 if (aOrder == bOrder)
-                   return NSOrderedSame;
+                 if (aOrder == bOrder) {
+                   return [a compare:b];
+                 }
                  return aOrder < bOrder ? NSOrderedAscending
                                         : NSOrderedDescending;
                }];

ios/interfaces/StyleBase.mm

@@ -45,7 +45,7 @@ - (BOOL)appliesStylingToTyping {
   return NO;
 }
 
-// determines the order of which the styles are applied
+// determines the order in which the styles are applied
 - (NSInteger)stylingPriority {
   return 0;
 }

ios/utils/ItalicUtils.mm

@@ -6,10 +6,8 @@
 static const CGFloat kObliquenessFallback = 0.2;
 
 typedef NS_ENUM(NSInteger, ItalicKind) {
-  // whitespace and other invisible characters - takes over the kind of its
-  // neighbours
-  ItalicKindNeutral,
-  // character must not be slanted at all (text attachments)
+  // character must not be slanted at all (whitespace, control characters,
+  // text attachments)
   ItalicKindNone,
   // font has a real italic glyph for the character
   ItalicKindFont,
@@ -97,8 +95,6 @@ + (void)applyItalicForFont:(UIFont *)font
                                                hasItalicFace:hasItalicFace])];
                       }];
 
-  [self resolveNeutralKinds:clusterKinds];
-
   // merge neighbouring clusters of the same kind and apply the style
   NSUInteger index = 0;
   while (index < clusterKinds.count) {
@@ -129,7 +125,7 @@ + (ItalicKind)kindForCluster:(NSString *)cluster
                hasItalicFace:(BOOL)hasItalicFace {
   if ([cluster rangeOfCharacterFromSet:[NeutralCharacters() invertedSet]]
           .location == NSNotFound) {
-    return ItalicKindNeutral;
+    return ItalicKindNone;
   }
 
   // we just need to analyze the first unicode character to classify the whole
@@ -154,23 +150,10 @@ + (ItalicKind)kindForCluster:(NSString *)cluster
     return ItalicKindFont;
   }
 
-  // italic is not supported, we use the slate instead
+  // italic is not supported, we use the slant instead
   return ItalicKindOblique;
 }
 
-// neutral clusters take over the preceding kind
-+ (void)resolveNeutralKinds:(NSMutableArray<NSNumber *> *)kinds {
-  ItalicKind previous = ItalicKindNeutral;
-  for (NSUInteger i = 0; i < kinds.count; i += 1) {
-    ItalicKind kind = (ItalicKind)[kinds[i] integerValue];
-    if (kind == ItalicKindNeutral) {
-      kinds[i] = @(previous);
-    } else {
-      previous = kind;
-    }
-  }
-}
-
 + (void)applyKind:(ItalicKind)kind
          toSegment:(NSRange)segment
      inTextStorage:(NSTextStorage *)textStorage
@@ -188,7 +171,6 @@ + (void)applyKind:(ItalicKind)kind
                         range:segment];
     break;
   case ItalicKindNone:
-  case ItalicKindNeutral:
     [textStorage removeAttribute:NSObliquenessAttributeName range:segment];
     break;
   }