1 files changed, 144 insertions, 0 deletions
diff --git a/Firestore/third_party/Immutable/FSTImmutableSortedSet.m b/Firestore/third_party/Immutable/FSTImmutableSortedSet.m
new file mode 100644
index 0000000..a13a79e
--- /dev/null
+++ b/Firestore/third_party/Immutable/FSTImmutableSortedSet.m
@@ -0,0 +1,144 @@
+#import "FSTImmutableSortedSet.h"
+
+#import "FSTImmutableSortedDictionary.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FSTImmutableSortedSet ()
+@property(nonatomic, strong) FSTImmutableSortedDictionary *dictionary;
+@end
+
+@implementation FSTImmutableSortedSet
+
++ (FSTImmutableSortedSet *)setWithComparator:(NSComparator)comparator {
+  return [FSTImmutableSortedSet setWithKeysFromDictionary:@{} comparator:comparator];
+}
+
++ (FSTImmutableSortedSet *)setWithKeysFromDictionary:(NSDictionary *)dictionary
+                                          comparator:(NSComparator)comparator {
+  FSTImmutableSortedDictionary *setDict =
+      [FSTImmutableSortedDictionary dictionaryWithDictionary:dictionary comparator:comparator];
+  return [[FSTImmutableSortedSet alloc] initWithDictionary:setDict];
+}
+
+// Designated initializer.
+- (id)initWithDictionary:(FSTImmutableSortedDictionary *)dictionary {
+  self = [super init];
+  if (self != nil) {
+    _dictionary = dictionary;
+  }
+  return self;
+}
+
+- (BOOL)isEqual:(id)object {
+  if (![object isKindOfClass:[FSTImmutableSortedSet class]]) {
+    return NO;
+  }
+
+  FSTImmutableSortedSet *other = (FSTImmutableSortedSet *)object;
+
+  return [self.dictionary isEqual:other.dictionary];
+}
+
+- (NSUInteger)hash {
+  return [self.dictionary hash];
+}
+
+- (BOOL)containsObject:(id)object {
+  return [self.dictionary containsKey:object];
+}
+
+- (FSTImmutableSortedSet *)setByAddingObject:(id)object {
+  FSTImmutableSortedDictionary *newDictionary =
+      [self.dictionary dictionaryBySettingObject:[NSNull null] forKey:object];
+  if (newDictionary != self.dictionary) {
+    return [[FSTImmutableSortedSet alloc] initWithDictionary:newDictionary];
+  } else {
+    return self;
+  }
+}
+
+- (FSTImmutableSortedSet *)setByRemovingObject:(id)object {
+  FSTImmutableSortedDictionary *newDictionary =
+      [self.dictionary dictionaryByRemovingObjectForKey:object];
+  if (newDictionary != self.dictionary) {
+    return [[FSTImmutableSortedSet alloc] initWithDictionary:newDictionary];
+  } else {
+    return self;
+  }
+}
+
+- (id)firstObject {
+  return [self.dictionary minKey];
+}
+
+- (id)lastObject {
+  return [self.dictionary maxKey];
+}
+
+- (id)predecessorObject:(id)entry {
+  return [self.dictionary predecessorKey:entry];
+}
+
+- (NSUInteger)indexOfObject:(id)object {
+  return [self.dictionary indexOfKey:object];
+}
+
+- (NSUInteger)count {
+  return [self.dictionary count];
+}
+
+- (BOOL)isEmpty {
+  return [self.dictionary isEmpty];
+}
+
+- (void)enumerateObjectsUsingBlock:(void (^)(id, BOOL *))block {
+  [self enumerateObjectsReverse:NO usingBlock:block];
+}
+
+- (void)enumerateObjectsFrom:(id)start to:(_Nullable id)end usingBlock:(void (^)(id, BOOL *))block {
+  NSEnumerator *enumerator = [self.dictionary keyEnumeratorFrom:start to:end];
+  id item = [enumerator nextObject];
+  while (item) {
+    BOOL stop = NO;
+    block(item, &stop);
+    if (stop) {
+      return;
+    }
+    item = [enumerator nextObject];
+  }
+}
+
+- (void)enumerateObjectsReverse:(BOOL)reverse usingBlock:(void (^)(id, BOOL *))block {
+  [self.dictionary enumerateKeysAndObjectsReverse:reverse
+                                       usingBlock:^(id key, id value, BOOL *stop) {
+                                         block(key, stop);
+                                       }];
+}
+
+- (NSEnumerator *)objectEnumerator {
+  return [self.dictionary keyEnumerator];
+}
+
+- (NSEnumerator *)objectEnumeratorFrom:(id)startKey {
+  return [self.dictionary keyEnumeratorFrom:startKey];
+}
+
+- (NSString *)description {
+  NSMutableString *str = [[NSMutableString alloc] init];
+  __block BOOL first = YES;
+  [str appendString:@"FSTImmutableSortedSet ( "];
+  [self enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
+    if (!first) {
+      [str appendString:@", "];
+    }
+    first = NO;
+    [str appendString:[NSString stringWithFormat:@"%@", obj]];
+  }];
+  [str appendString:@" )"];
+  return str;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END