[ios, macos] Added debug descriptions for runtime styling classes

platform/darwin/src/MGLForegroundStyleLayer.m

@@ -10,4 +10,11 @@
     return self;
 }
 
+- (NSString *)description {
+    return [NSString stringWithFormat:
+            @"<%@: %p; identifier = %@; sourceIdentifier = %@; visible = %@>",
+            NSStringFromClass([self class]), (void *)self, self.identifier,
+            self.sourceIdentifier, self.visible ? @"YES" : @"NO"];
+}
+
 @end

platform/darwin/src/MGLGeoJSONSource.mm

@@ -192,4 +192,10 @@ const MGLGeoJSONSourceOption MGLGeoJSONSourceOptionSimplificationTolerance = @"M
     _features = MGLFeaturesFromMBGLFeatures(featureCollection);
 }
 
+- (NSString *)description
+{
+    return [NSString stringWithFormat:@"<%@: %p; identifier = %@; URL = %@; geoJSONData = %@; features = %@>",
+            NSStringFromClass([self class]), (void *)self, self.identifier, self.URL, self.geoJSONData, self.features];
+}
+
 @end

platform/darwin/src/MGLRasterSource.mm

@@ -73,4 +73,12 @@
     self.rawSource = _pendingSource.get();
 }
 
+- (NSString *)description
+{
+    return [NSString stringWithFormat:
+            @"<%@: %p; identifier = %@; URL = %@; tileSet = %@; tileSize = %lu>",
+            NSStringFromClass([self class]), (void *)self, self.identifier, self.URL,
+            self.tileSet, (unsigned long)self.tileSize];
+}
+
 @end

platform/darwin/src/MGLSource.mm

@@ -12,4 +12,9 @@
     return self;
 }
 
+- (NSString *)description {
+    return [NSString stringWithFormat:@"<%@: %p; identifier = %@>",
+            NSStringFromClass([self class]), (void *)self, self.identifier];
+}
+
 @end

platform/darwin/src/MGLStyleLayer.mm

@@ -51,4 +51,11 @@
     return self.rawLayer->getMinZoom();
 }
 
+- (NSString *)description
+{
+    return [NSString stringWithFormat:@"<%@: %p; identifier = %@; visible = %@>",
+            NSStringFromClass([self class]), (void *)self, self.identifier,
+            self.visible ? @"YES" : @"NO"];
+}
+
 @end

platform/darwin/src/MGLTileSet.mm

@@ -84,4 +84,10 @@
     return tileset;
 }
 
+- (NSString *)description
+{
+    return [NSString stringWithFormat:@"<%@: %p; tileURLTemplates = %@>",
+            NSStringFromClass([self class]), (void *)self, self.tileURLTemplates];
+}
+
 @end

platform/darwin/src/MGLVectorSource.mm

@@ -72,4 +72,10 @@ static NSString *MGLVectorSourceType   = @"vector";
     self.rawSource = _pendingSource.get();
 }
 
+- (NSString *)description
+{
+    return [NSString stringWithFormat:@"<%@: %p; identifier = %@; URL = %@; tileSet = %@>",
+            NSStringFromClass([self class]), (void *)self, self.identifier, self.URL, self.tileSet];
+}
+
 @end

platform/darwin/src/MGLVectorStyleLayer.m

@@ -13,4 +13,13 @@
     return nil;
 }
 
+- (NSString *)description {
+    return [NSString stringWithFormat:
+            @"<%@: %p; identifier = %@; sourceIdentifier = %@; "
+            @"sourceLayerIdentifier = %@; predicate = %@; visible = %@>",
+            NSStringFromClass([self class]), (void *)self, self.identifier,
+            self.sourceIdentifier, self.sourceLayerIdentifier, self.predicate,
+            self.visible ? @"YES" : @"NO"];
+}
+
 @end