add a synthetic See Also section containing other modules in the same package to module pages

Author: tayloraswift

Sources/UnidocLinker/Linker/DynamicLinker.swift

@@ -79,6 +79,7 @@ extension DynamicLinker
             diagnostics: diagnostics,
             extensions: extensions)
 
+        self.synthesizeTopics()
         self.link(clients: clients)
 
         //  Create file records.
@@ -107,9 +108,34 @@ extension DynamicLinker
 }
 extension DynamicLinker
 {
+    private mutating
+    func synthesizeTopics()
+    {
+
+    }
     private mutating
     func link(clients:[DynamicClientGroup])
     {
+        //  Create a synthetic topic containing all the cultures. This will become a “See Also”
+        //  for their module pages, unless they belong to a custom topic group.
+        let cultures:Record.Group.Topic = .init(id: self.topic.id(),
+            members: self.current.graph.cultures.indices.sorted
+            {
+                self.current.graph.namespaces[$0] <
+                self.current.graph.namespaces[$1]
+            }
+            .map
+            {
+                .scalar(self.current.zone + $0 * .module)
+            })
+
+        self.groups.append(.topic(cultures))
+
+        for c:Int in self.current.graph.cultures.indices
+        {
+            self.topics[c * .module] = cultures.id
+        }
+
         //  First pass to create the topic records, which also populates topic memberships.
         for ((culture, input), clients):
             ((Int, SymbolGraph.Culture), DynamicClientGroup) in zip(zip(
@@ -191,7 +217,7 @@ extension DynamicLinker
 
             for case .scalar(let master) in record.members
             {
-                //  TODO: diagnose overlapping topics
+                //  This may replace a synthesized topic.
                 if  let local:Int32 = master - self.current.zone
                 {
                     self.topics[local] = record.id

Sources/UnidocPages/WideQuery.Output (ext).swift

@@ -16,8 +16,7 @@ extension WideQuery.Output:ServerResponseFactory
                 type: .text(.plain, charset: .utf8)))
         }
 
-        if  let master:Record.Master = principal.master,
-            let tree:Record.NounTree = principal.tree
+        if  let master:Record.Master = principal.master
         {
             let resource:ServerResource
             let inliner:Inliner = .init(principal: master.id, zone: principal.zone)
@@ -33,27 +32,31 @@ extension WideQuery.Output:ServerResponseFactory
                 inliner.outlines += $0.outlines
             }
 
+            /// Tree won’t exist if the module contains no declarations. (For example,
+            /// an `@_exported` shim.)
+            let nouns:[Record.Noun] = principal.tree?.rows ?? []
+
             switch master
             {
             case .article(let master):
                 let page:Site.Docs.Article = .init(inliner,
                     master: master,
                     groups: principal.groups,
-                    nouns: tree.rows)
+                    nouns: nouns)
                 resource = page.rendered()
 
             case .culture(let master):
                 let page:Site.Docs.Culture = .init(inliner,
                     master: master,
                     groups: principal.groups,
-                    nouns: tree.rows)
+                    nouns: nouns)
                 resource = page.rendered()
 
             case .decl(let master):
                 let page:Site.Docs.Decl = .init(inliner,
                     master: master,
                     groups: principal.groups,
-                    nouns: tree.rows)
+                    nouns: nouns)
                 resource = page.rendered()
 
             case .file:

Sources/UnidocRecords/Groups/Record.Group.Topic.swift

@@ -9,9 +9,9 @@ extension Record.Group
         let id:Unidoc.Scalar
 
         public
-        let culture:Unidoc.Scalar
+        let culture:Unidoc.Scalar?
         public
-        let scope:Unidoc.Scalar
+        let scope:Unidoc.Scalar?
 
         /// Additional scalars to prefetch when this extension is loaded.
         /// This is used to obtain the masters for passage referents in the
@@ -27,8 +27,8 @@ extension Record.Group
 
         @inlinable public
         init(id:Unidoc.Scalar,
-            culture:Unidoc.Scalar,
-            scope:Unidoc.Scalar,
+            culture:Unidoc.Scalar? = nil,
+            scope:Unidoc.Scalar? = nil,
             prefetch:[Unidoc.Scalar] = [],
             overview:Record.Passage? = nil,
             members:[Record.Link] = [])

Sources/UnidocRecords/Groups/Record.Group.swift

@@ -26,9 +26,10 @@ extension Record.Group
         /// constraints, which contain scalars.
         case conditions = "g"
 
-        /// Always present, contains a scalar.
+        /// Always present in ``Extension``, optional in ``Topic``, and contains a scalar.
         case culture = "c"
-        /// Always present, contains a scalar (but usually doesn’t need a secondary lookup).
+        /// Always present in ``Extension``, optional in ``Topic``, and contains a scalar.
+        /// Usually doesn’t need a secondary lookup.
         case scope = "X"
 
         /// Optional and appears in ``Extension`` only.
@@ -133,7 +134,7 @@ extension Record.Group:BSONDocumentEncodable
             bson[.overview] = self.overview
             bson[.members] = self.members.isEmpty ? nil : self.members
 
-            zones.update(with: self.culture.zone)
+            zones.update(with: self.culture?.zone)
             zones.update(with: self.prefetch)
         }
 
@@ -149,8 +150,8 @@ extension Record.Group:BSONDocumentDecodable
         if  case .topic? = id.plane
         {
             self = .topic(.init(id: id,
-                culture: try bson[.culture].decode(),
-                scope: try bson[.scope].decode(),
+                culture: try bson[.culture]?.decode(),
+                scope: try bson[.scope]?.decode(),
                 prefetch: try bson[.prefetch]?.decode() ?? [],
                 overview: try bson[.overview]?.decode(),
                 members: try bson[.members]?.decode() ?? []))