Update to the latest API Spec.

Database
* getDocument(id) will return null if document is deleted or doesn’t exists.
* contains(id) will return false if document is deleted or doesn’t exist
* No Predicate Query
* No allDocuments()

Document
* Change edit() to toMutable().
* MutableDocument.toMutable() should also copy the MutableDocument.

Dictionary and Array
* Add Dictionary.toMutable() and Array.toMutable().
* Rename Dictionary.setObject(key, value) to Dictionary.setValue(key, value) for all platforms. Currently Objective-C has both setObject() and setValue() as we need to review if it’s appropriate to override setValue() as it is a part of KVO.
* Rename Array.set/add/insertObject(index) to Array.set/add/insertValue(index) for all platforms.
* Dictionary.setValue(key, null) will set null value in all platforms.
* Dictionary.getBoolean(key) and Array.getBoolean(index) will have the following behavior for all platform (I understand that LiteCore implements this behavior):
	if (value == null || value == NSNull)
		return false
	else if (value is number)
		return number != 0
	else
		return true

MutableFragment
* Add type setters

Query
* Change run() to execute()
* Meta
    * Removed Expression.meta(). Use Meta.id and Meta.sequence directly to inline with Function.
    * Removed Expression.notLessThan, notLessThanOrEqualTo, not GreaterThan, notGreaterThanOrEqualTo, notLike, notRegex, notMatch, notBetween, notIn
    * Make sure to not Remove IS and ISNOT
* ArrayExpression
    * Move Array related expressions (Any, Every, AnyAndEvery) into its own class: ArrayExpression + ArrayExpressionIn + ArrayExpressionSatisfies.
* Array Functions
    * Moved array related functions from Function to ArrayFunction.
    * See: couchbaselabs/couchbase-lite-api-spec@7e1174a
* PropertyExpression
    * Extract into its own file instead of having it nested in Expression class.
* Function
    * Not extends Expression. Each function method returns Expression.
* FullText:
    * Have FullTextExpression and FullTextFunction.
    * FullTextExpression has a static index(indexName) method for creating FullTextExpression object with the given index name.
    * Moved Expression.match(object) to FullTextExpression.match(text). Support only match string now.
    * Moved Function.rank(object) to FullTextFunction.rank(indexName)
    * See: couchbaselabs/couchbase-lite-api-spec@7e1174a
* SelectResult
    * Add SelectResult.property(property)
* Query now supports add/remove change listener. When a new listener is added, the listener will get first notified with the current query result.
* Query.setParameters() and getParameters() now have copy behavior. When setting a new Parameters, if there is a change listener added, re-run the query and notify.
* Change Parameters.setObject(name, value) to setValue(name, value).

Index
* Change Index.ValueIndexOn() and Index.FTSIndexOn() to  Index.valueIndex(items) and Index.fullTextIndex(items).
* Index.fullTextIndex(items) allows to set multiple items. Rename FTSIndex to FullTextIndex and FTSIndexItem to FullTextIndexItem.
* Add FullTextIndexItem.property(name) and remove FullTextIndexItem.expression().
* Add ValueIndexItem.property(name).

LiveQuery
* No LiveQuery. Query itself can add/remove change listeners.

ChangeListener
* addChangeListener(listener) returns ListenerToken. ListenerToken is an opaque interface with no methods.
* removeChangeListener(token) takes listener token.
* Rename Database.addChangeListener(documentID, listener) to Database.addDocumentChangeListener(id, listener).
* Add {Database, Query, Replicator}.add{Document}ChangeListener(id}, queue, listener) in all platforms.
    * Java: Executor
    * .NET: TaskFactory
    * iOS: DispatchQueue
* DatabaseChange doesn’t have .external property. We could add this later based on demand in 2.x.

ReplicatorConfiguration
* Flatten Filter
    * Move Filter.channels and Filter.documentIDs to the top level of ReplicatorConfiguration
    * couchbaselabs/couchbase-lite-api-spec@6b2795e

SessionAuthenticator
* Make expires type safe
    * Have two constructors instead of one, one for expires Date and one for expires string.
    * couchbaselabs/couchbase-lite-api-spec@f45d318

Default Conflict Resolver Algorithm
* Delete always wins.
* Longest generation wins or Max RevID wins if the generations are the same.

Document Equality (Pending, not included in this commit)
* Two documents are equals when they are from the same database, they have the same ID, and they have the same content.

#1960

Objective-C/CBLArray.h

@@ -11,6 +11,8 @@
 @class CBLBlob;
 @class CBLDictionary;
 @class CBLArray;
+@class CBLMutableArray;
+
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -21,55 +23,62 @@ NS_ASSUME_NONNULL_BEGIN
 @property (readonly) NSUInteger count;
 
 /**
- Gets value as a CBLArray, which is a mapping object of an array value.
- Returns nil if the value doesn't exists, or its value is not an array.
+ Gets value at the given index as an object. The object types are CBLBlob,
+ CBLArray, CBLDictionary, NSNumber, or NSString based on the underlying
+ data type; or nil if the value is nil.
  
  @param index The index.
- @return The CBLArray object or nil.
+ @return The object or nil.
  */
-- (nullable CBLArray*) arrayAtIndex: (NSUInteger)index;
+- (nullable id) objectAtIndex: (NSUInteger)index;
 
-/**
- Get value at the given index as a CBLBlob.
- Returns nil if the value doesn't exist, or its value is not a CBLBlob.
+/*
+ Gets value at the given index. The object types are CBLBlob,
+ CBLArray, CBLDictionary, NSNumber, or NSString based on the underlying
+ data type; or nil if the value is nil.
  
  @param index The index.
- @return The CBLBlob object or nil.
+ @return The object or nil.
  */
-- (nullable CBLBlob*) blobAtIndex: (NSUInteger)index;
+- (nullable id) valueAtIndex: (NSUInteger)index;
 
-/** 
- Gets value at the given index as a boolean.
- Returns YES if the value exists, and is either `true` or a nonzero number.
+/**
+ Gets value at the given index as a string.
+ Returns nil if the value doesn't exist, or its value is not a string.
  
  @param index The index.
- @return The boolean value.
+ @return The NSString object or nil.
  */
-- (BOOL) booleanAtIndex: (NSUInteger)index;
+- (nullable NSString*) stringAtIndex: (NSUInteger)index;
 
 /**
- Gets value at the given index as an NSDate.
- JSON does not directly support dates, so the actual property value must be a string, which is
- then parsed according to the ISO-8601 date format (the default used in JSON.)
- Returns nil if the value doesn't exist, is not a string, or is not parseable as a date.
- NOTE: This is not a generic date parser! It only recognizes the ISO-8601 format, with or
- without milliseconds.
+ Gets value at the given index as a number.
+ Returns nil if the value doesn't exist, or its value is not a number.
  
  @param index The index.
- @return The NSDate object or nil.
+ @return The NSNumber object or nil.
  */
-- (nullable NSDate*) dateAtIndex: (NSUInteger)index;
+- (nullable NSNumber*) numberAtIndex: (NSUInteger)index;
 
 /**
- Get value at the given index as a CBLDictionary, which is a mapping object of
- a dictionary value.
- Returns nil if the value doesn't exists, or its value is not a dictionary.
+ Gets value at the given index as an integer value.
+ Floating point values will be rounded. The value `true` is returned as 1, `false` as 0.
+ Returns 0 if the value doesn't exist or does not have a numeric value.
  
  @param index The index.
- @return The CBLDictionary object or nil.
+ @return The integer value.
  */
-- (nullable CBLDictionary*) dictionaryAtIndex: (NSUInteger)index;
+- (NSInteger) integerAtIndex: (NSUInteger)index;
 
+/**
+ Gets value at the given index as a long long value.
+ Floating point values will be rounded. The value `true` is returned as 1, `false` as 0.
+ Returns 0 if the value doesn't exist or does not have a numeric value.
+ 
+ @param index The index.
+ @return The long long value.
+ */
+- (long long) longLongAtIndex: (NSUInteger)index;
 
 /**
  Gets value at the given index as a float value.
@@ -81,7 +90,7 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (float) floatAtIndex: (NSUInteger)index;
 
-/** 
+/**
  Gets value at the given index as a double value.
  Integers will be converted to double. The value `true` is returned as 1.0, `false` as 0.0.
  Returns 0.0 if the property doesn't exist or does not have a numeric value.
@@ -91,55 +100,59 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (double) doubleAtIndex: (NSUInteger)index;
 
-/**
- Gets value at the given index as an integer value.
- Floating point values will be rounded. The value `true` is returned as 1, `false` as 0.
- Returns 0 if the value doesn't exist or does not have a numeric value.
+/** 
+ Gets value at the given index as a boolean.
+ Returns YES if the value exists, and is either `true` or a nonzero number.
  
  @param index The index.
- @return The integer value.
+ @return The boolean value.
  */
-- (NSInteger) integerAtIndex: (NSUInteger)index;
+- (BOOL) booleanAtIndex: (NSUInteger)index;
 
 /**
- Gets value at the given index as a long long value.
- Floating point values will be rounded. The value `true` is returned as 1, `false` as 0.
- Returns 0 if the value doesn't exist or does not have a numeric value.
+ Gets value at the given index as an NSDate.
+ JSON does not directly support dates, so the actual property value must be a string, which is
+ then parsed according to the ISO-8601 date format (the default used in JSON.)
+ Returns nil if the value doesn't exist, is not a string, or is not parseable as a date.
+ NOTE: This is not a generic date parser! It only recognizes the ISO-8601 format, with or
+ without milliseconds.
  
  @param index The index.
- @return The long long value.
+ @return The NSDate object or nil.
  */
-- (long long) longLongAtIndex: (NSUInteger)index;
+- (nullable NSDate*) dateAtIndex: (NSUInteger)index;
 
-/** 
- Gets value at the given index as a number.
- Returns nil if the value doesn't exist, or its value is not a number.
+/**
+ Get value at the given index as a CBLBlob.
+ Returns nil if the value doesn't exist, or its value is not a CBLBlob.
  
  @param index The index.
- @return The NSNumber object or nil.
+ @return The CBLBlob object or nil.
  */
-- (nullable NSNumber*) numberAtIndex: (NSUInteger)index;
+- (nullable CBLBlob*) blobAtIndex: (NSUInteger)index;
 
 /**
- Gets value at the given index as an object. The object types are CBLBlob,
- CBLArray, CBLDictionary, NSNumber, or NSString based on the underlying
- data type; or nil if the value is nil.
+ Gets value as a CBLArray, which is a mapping object of an array value.
+ Returns nil if the value doesn't exists, or its value is not an array.
  
  @param index The index.
- @return The object or nil.
+ @return The CBLArray object or nil.
  */
-- (nullable id) objectAtIndex: (NSUInteger)index;
+- (nullable CBLArray*) arrayAtIndex: (NSUInteger)index;
 
 /**
- Gets value at the given index as a string.
- Returns nil if the value doesn't exist, or its value is not a string.
+ Get value at the given index as a CBLDictionary, which is a mapping object of
+ a dictionary value.
+ Returns nil if the value doesn't exists, or its value is not a dictionary.
  
  @param index The index.
- @return The NSString object or nil.
+ @return The CBLDictionary object or nil.
  */
-- (nullable NSString*) stringAtIndex: (NSUInteger)index;
+- (nullable CBLDictionary*) dictionaryAtIndex: (NSUInteger)index;
 
-/** 
+#pragma mark - Data
+
+/**
  Gets content of the current object as an NSArray. The values contained in the returned
  NSArray object are all JSON based values.
  
@@ -154,6 +167,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype) init NS_UNAVAILABLE;
 
+- (CBLMutableArray*) toMutable;
+
 @end
 
 NS_ASSUME_NONNULL_END

Objective-C/CBLArray.mm

@@ -101,34 +101,33 @@ static id _getObject(MArray<id> &array, NSUInteger index, Class asClass =nil) {
     return obj;
 }
 
-
-- (nullable CBLArray*) arrayAtIndex: (NSUInteger)index {
-    return _getObject(_array, index, [CBLArray class]);
+- (nullable id) objectAtIndex: (NSUInteger)index {
+    return _getObject(_array, index);
 }
 
 
-- (nullable CBLBlob*) blobAtIndex: (NSUInteger)index {
-    return _getObject(_array, index, [CBLBlob class]);
+- (nullable id) valueAtIndex: (NSUInteger)index {
+    return _getObject(_array, index);
 }
 
 
-- (BOOL) booleanAtIndex: (NSUInteger)index {
-    return asBool(_get(_array, index), _array);
+- (nullable NSString*) stringAtIndex: (NSUInteger)index {
+    return _getObject(_array, index, [NSString class]);
 }
 
 
-- (nullable NSDate*) dateAtIndex: (NSUInteger)index {
-    return asDate(_getObject(_array, index));
+- (nullable NSNumber*) numberAtIndex: (NSUInteger)index {
+    return _getObject(_array, index, [NSNumber class]);
 }
 
 
-- (nullable CBLDictionary*) dictionaryAtIndex: (NSUInteger)index {
-    return _getObject(_array, index, [CBLDictionary class]);
+- (NSInteger) integerAtIndex: (NSUInteger)index {
+    return asInteger(_get(_array, index), _array);
 }
 
 
-- (double) doubleAtIndex: (NSUInteger)index {
-    return asDouble(_get(_array, index), _array);
+- (long long) longLongAtIndex: (NSUInteger)index {
+    return asLongLong(_get(_array, index), _array);
 }
 
 
@@ -137,28 +136,33 @@ - (float) floatAtIndex: (NSUInteger)index {
 }
 
 
-- (NSInteger) integerAtIndex: (NSUInteger)index {
-    return asInteger(_get(_array, index), _array);
+- (double) doubleAtIndex: (NSUInteger)index {
+    return asDouble(_get(_array, index), _array);
 }
 
 
-- (long long) longLongAtIndex: (NSUInteger)index {
-    return asLongLong(_get(_array, index), _array);
+- (BOOL) booleanAtIndex: (NSUInteger)index {
+    return asBool(_get(_array, index), _array);
 }
 
 
-- (nullable NSNumber*) numberAtIndex: (NSUInteger)index {
-    return _getObject(_array, index, [NSNumber class]);
+- (nullable NSDate*) dateAtIndex: (NSUInteger)index {
+    return asDate(_getObject(_array, index));
 }
 
 
-- (nullable NSString*) stringAtIndex: (NSUInteger)index {
-    return _getObject(_array, index, [NSString class]);
+- (nullable CBLBlob*) blobAtIndex: (NSUInteger)index {
+    return _getObject(_array, index, [CBLBlob class]);
 }
 
 
-- (nullable id) objectAtIndex: (NSUInteger)index {
-    return _getObject(_array, index);
+- (nullable CBLArray*) arrayAtIndex: (NSUInteger)index {
+    return _getObject(_array, index, [CBLArray class]);
+}
+
+
+- (nullable CBLDictionary*) dictionaryAtIndex: (NSUInteger)index {
+    return _getObject(_array, index, [CBLDictionary class]);
 }
 
 
@@ -167,6 +171,9 @@ - (NSUInteger) count {
 }
 
 
+#pragma mark - Data
+
+
 - (NSArray*) toArray {
     auto count = _array.count();
     NSMutableArray* result = [NSMutableArray arrayWithCapacity: count];
@@ -176,6 +183,14 @@ - (NSArray*) toArray {
 }
 
 
+#pragma mark - Mutable
+
+
+- (CBLMutableArray*) toMutable {
+    return [self mutableCopy];
+}
+
+
 - (id) cbl_toPlainObject {
     return [self toArray];
 }

Objective-C/CBLConflictResolver.m

@@ -15,9 +15,18 @@
 @implementation CBLDefaultConflictResolver
 
 - (nullable CBLDocument*) resolve: (CBLConflict*)conflict {
-    // Default resolution algorithm is "most active wins", i.e. higher generation number.
+    // Default resolution algorithm:
+    // 1. DELETE always wins.
+    // 2. Most active wins (Higher generation number).
+    // 3. Higher RevID wins.
     CBLDocument *mine = conflict.mine, *theirs = conflict.theirs;
-    if (mine.generation >= theirs.generation)       // hope I die before I get old
+    if (theirs.isDeleted)
+        return theirs;
+    else if (mine.isDeleted)
+        return mine;
+    else if (mine.generation >= theirs.generation) // hope I die before I get old
+        return mine;
+    else if ([mine.revID compare: theirs.revID] > 0)
         return mine;
     else
         return theirs;
@@ -26,14 +35,10 @@ - (nullable CBLDocument*) resolve: (CBLConflict*)conflict {
 @end
 
 
-
-
 @implementation CBLConflict
 
-
 @synthesize mine=_mine, theirs=_theirs, base=_base;
 
-
 - (instancetype) initWithMine: (CBLDocument*)mine
                        theirs: (CBLDocument*)theirs
                          base: (CBLDocument*)base
@@ -47,5 +52,4 @@ - (instancetype) initWithMine: (CBLDocument*)mine
     return self;
 }
 
-
 @end