Type out the ctx.fetchObjects methods

Bind them to a specific DatabaseObject type,
makes sense.
There is still some `Any` in the stack that
should be removed, but this is a better starting
point.
Also rename the now-outdated method name.

Sources/ZeeQL/Access/DatabaseChannel.swift

@@ -3,7 +3,7 @@
 //  ZeeQL
 //
 //  Created by Helge Hess on 27/02/17.
-//  Copyright © 2017-2020 ZeeZide GmbH. All rights reserved.
+//  Copyright © 2017-2024 ZeeZide GmbH. All rights reserved.
 //
 
 open class DatabaseChannelBase {
@@ -722,7 +722,7 @@ open class DatabaseChannelBase {
    *
    * - returns: null if there are no more objects, or the fetched object/record
    */
-  func fetchObject() -> DatabaseObject? {
+  public func fetchObject() -> DatabaseObject? {
     /* use iterator if the objects are already fetched in total */
     // TODO: make the function throws
 
@@ -1116,11 +1116,12 @@ open class DatabaseChannelBase {
 
 // MARK: - Typed Concrete Class
 
-open class TypedDatabaseChannel<ObjectType: DatabaseObject> : DatabaseChannelBase,
-                                                              IteratorProtocol
+open class TypedDatabaseChannel<ObjectType> : DatabaseChannelBase,
+                                              IteratorProtocol
+  where ObjectType: DatabaseObject
 {
 
-  public var objects : IndexingIterator<[ObjectType]>?
+  public var objects : IndexingIterator<[ ObjectType ]>?
 
   override var hasObjectIterator : Bool { return objects != nil }
 
@@ -1166,15 +1167,15 @@ open class TypedDatabaseChannel<ObjectType: DatabaseObject> : DatabaseChannelBas
    * This is the primary method for fetches and has additional handling for
    * prefetched relationships.
    * 
-   * - parameters:
+   * - Parameters:
    *   - fs: The FetchSpecification which outlines how objects are being
    *         fetched.
    *   - ec: TODO
    */
-  override func selectObjectsWithFetchSpecification(_ fs: FetchSpecification,
-                                                    _ ec: ObjectTrackingContext?
-                                                              = nil)
-                throws
+  override public func selectObjectsWithFetchSpecification(
+    _ fs: FetchSpecification,
+    _ ec: ObjectTrackingContext? = nil
+  ) throws
   {
     guard let prefetchRelPathes = fs.prefetchingRelationshipKeyPathes,
           !prefetchRelPathes.isEmpty

Sources/ZeeQL/Access/DatabaseContext.swift

@@ -3,7 +3,7 @@
 //  ZeeQL
 //
 //  Created by Helge Hess on 03/03/2017.
-//  Copyright © 2017-2019 ZeeZide GmbH. All rights reserved.
+//  Copyright © 2017-2024 ZeeZide GmbH. All rights reserved.
 //
 
 /**
@@ -50,21 +50,28 @@ public class DatabaseContext : ObjectStore, SmartDescription {
     }
   }
 
-  public func objectsWith(fetchSpecification fs : FetchSpecification,
-                          in tc                 : ObjectTrackingContext,
-                          _ cb                  : ( Any ) -> Void) throws
+  @inlinable
+  public func objectsWithFetchSpecification<O>(
+    _  fetchSpecification : FetchSpecification,
+    in    trackingContext : ObjectTrackingContext,
+    _               yield : ( O ) throws -> Void
+  ) throws
+    where O: DatabaseObject
   {
-    if fs.requiresAllQualifierBindingVariables {
-      if let keys = fs.qualifier?.bindingKeys, !keys.isEmpty {
-        throw Error.FetchSpecificationHasUnresolvedBindings(fs)
+    if fetchSpecification.requiresAllQualifierBindingVariables {
+      if let keys = fetchSpecification.qualifier?.bindingKeys, !keys.isEmpty {
+        throw Error.FetchSpecificationHasUnresolvedBindings(fetchSpecification)
       }
     }
 
-    let ch = DatabaseChannel(database: database)
-    try ch.selectObjectsWithFetchSpecification(fs, tc)
+    let ch = TypedDatabaseChannel<O>(database: database)
+    try ch
+      .selectObjectsWithFetchSpecification(fetchSpecification, trackingContext)
 
     while let o = ch.fetchObject() {
-      cb(o)
+      assert(o is O)
+      guard let typed = o as? O else { continue }
+      try yield(typed)
     }
   }
 

Sources/ZeeQL/Access/DatabaseDataSource.swift

@@ -72,11 +72,6 @@ open class DatabaseDataSource<Object: DatabaseObject>
                                           yield: ( Object ) throws -> Void)
     throws
   {
-    let results = try objectContext.objectsWith(fetchSpecification: fs)
-    for result in results {
-      assert(result is Object)
-      guard let object = result as? Object else { continue }
-      try yield(object)
-    }
+    try objectContext.objectsWithFetchSpecification(fs, yield)
   }
 }

Sources/ZeeQL/Control/ObjectStore.swift

@@ -3,7 +3,7 @@
 //  ZeeQL
 //
 //  Created by Helge Hess on 17/02/17.
-//  Copyright © 2017-2019 ZeeZide GmbH. All rights reserved.
+//  Copyright © 2017-2024 ZeeZide GmbH. All rights reserved.
 //
 
 public protocol ObjectWithGlobalID {
@@ -15,14 +15,16 @@ public protocol ObjectWithGlobalID {
  * A store which stores objects :-)
  *
  * Current subclasses:
- * - `ObjectTrackingContext` (an object uniquer)
- * - `DatabaseContext` (a store on top of `Database`)
+ * - ``ObjectTrackingContext`` (an object uniquer)
+ * - ``DatabaseContext`` (a store on top of `Database`)
  */
 public protocol ObjectStore {
 
-  // TBD: add throws?
-  func objectsWith(fetchSpecification : FetchSpecification,
-                   in tc              : ObjectTrackingContext,
-                   _ cb               : ( Any ) -> Void) throws
+  func objectsWithFetchSpecification<O>(
+    _ fetchSpecification : FetchSpecification,
+    in   trackingContext : ObjectTrackingContext,
+    _            yield   : ( O ) throws -> Void
+  ) throws
+    where O: DatabaseObject
 
 }

Sources/ZeeQL/Control/ObjectTrackingContext.swift

@@ -46,28 +46,47 @@ open class ObjectTrackingContext : ObjectStore {
 
   /**
    * Fetches the objects for the given specification. This works by calling
-   * `objectsWith(fetchSpecification:in:)` with the tracking context itself.
+   * ``objectsWithFetchSpecification(_:in:_:)`` with the tracking context
+   * itself.
    */
   @inlinable
-  open func objectsWith(fetchSpecification fs: FetchSpecification) throws
-            -> [ Any ]
+  open func objectsWithFetchSpecification<O>(_ type: O.Type = O.self,
+                                             _ fs: FetchSpecification) throws
+            -> [ O ]
+    where O: DatabaseObject
   {
-    var objects = [ Any ]()
-    try objectsWith(fetchSpecification: fs, in: self) {
-      objects.append($0)
-    }
+    var objects = [ O ]()
+    try objectsWithFetchSpecification(fs) { objects.append($0) }
     return objects
   }
 
   /**
-   * This method asks the `rootObjectStore` to fetch the objects specified
-   * in the _fs.
-   * Objects will get registered in the given tracking context.
+   * Fetches the objects for the given specification. This works by calling
+   * ``objectsWithFetchSpecification(_:in:_:)`` with the tracking context
+   * itself.
+   */
+  @inlinable
+  open func objectsWithFetchSpecification<O>(_ fs: FetchSpecification,
+                                             _ cb: ( O ) throws -> Void) throws
+    where O: DatabaseObject
+  {
+    return try objectsWithFetchSpecification(fs, in: self, cb)
+  }
+
+  /**
+   * This method asks the ``rootObjectStore`` to fetch the objects specified
+   * in the _fs (usually a ``DatabaseContext``).
+   *
+   * Objects will get registered in the given tracking context (usually `self`
+   * for ``ObjectTrackingContext``)
+   *
+   * This is the primitve method of ``ObjectStore``.
    */
   @inlinable
-  open func objectsWith(fetchSpecification fs: FetchSpecification,
-                        in tc: ObjectTrackingContext,
-                        _ cb: ( Any ) -> Void) throws
+  open func objectsWithFetchSpecification<O>(_ fs: FetchSpecification,
+                                             in tc: ObjectTrackingContext,
+                                             _ cb: ( O ) throws -> Void) throws
+    where O: DatabaseObject
   {
     if fs.requiresAllQualifierBindingVariables {
       if let q = fs.qualifier {
@@ -77,7 +96,7 @@ open class ObjectTrackingContext : ObjectStore {
       }
     }
 
-    return try rootObjectStore.objectsWith(fetchSpecification: fs, in: tc, cb)
+    return try rootObjectStore.objectsWithFetchSpecification(fs, in: tc, cb)
   }