Improved API to allow better manipulation using only Cursors

1 files changed, 281 insertions, 63 deletions

diff --git a/src/directed_graphs.adb b/src/directed_graphs.adb
index 3b4caee..4acf0fa 100644
--- a/src/directed_graphs.adb
+++ b/src/directed_graphs.adb
@@ -163,6 +163,31 @@ package body Directed_Graphs is
         Container.Edge_Labels.Insert (Edge, Label);
     end Append_Label;
 
+    procedure Append_Label
+           (Parent, Child : in out Cursor;
+            Label         : in     Edge_Label_Type) is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Edge (Parent, Child) then
+                raise Constraint_Error with "Graph does not contain edge";
+            end if;
+            if Has_Label (Parent, Child) then
+                raise Constraint_Error with "Edge already has label";
+            end if;
+        end if;
+        Parent.Container.Edge_Labels.Insert
+            ((From => Element (Parent), To => Element (Child)), Label);
+    end Append_Label;
+
 
 
 
@@ -321,6 +346,41 @@ package body Directed_Graphs is
         end;
     end Constant_Label_Reference;
 
+    function Constant_Label_Reference
+           (Parent, Child : in Cursor)
+        return Edge_Label_Constant_Reference is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Edge (Parent, Child) then
+                raise Constraint_Error with "Graph does not contain edge";
+            end if;
+            if not Has_Label (Parent, Child) then
+                raise Constraint_Error with "Edge does not have a label";
+            end if;
+        end if;
+        declare
+            Tamper : constant Help.Tamper_Counts_Access :=
+                Parent.Container.Tamper_Info'Unrestricted_Access;
+            Edge : Edge_Type := ((From => Element (Parent), To => Element (Child)));
+        begin
+            return Ref : constant Edge_Label_Constant_Reference :=
+               (Element => Parent.Container.Edge_Labels.Constant_Reference (Edge).Element,
+                Control => (Ada.Finalization.Controlled with Tamper))
+            do
+                Impl.Lock (Tamper.all);
+            end return;
+        end;
+    end Constant_Label_Reference;
+
 
 
 
@@ -533,39 +593,6 @@ package body Directed_Graphs is
 
 
 
-    -------------
-    -- Context --
-    -------------
-
-    procedure Context
-           (Container : in     Graph;
-            Node      : in     Node_Type;
-            Parents   :    out Node_Array;
-            Children  :    out Node_Array) is
-    begin
-        Parents := Container.Parents (Node);
-        Children := Container.Children (Node);
-    end Context;
-
-    procedure Context
-           (Position : in     Cursor;
-            Parents  :    out Node_Array;
-            Children :    out Node_Array) is
-    begin
-        if Impl.Checks then
-            if Position.Container = null then
-                raise Constraint_Error with "Graph does not exist";
-            end if;
-            if not Has_Element (Position) then
-                raise Constraint_Error with "Cursor points to nothing";
-            end if;
-        end if;
-        Position.Container.Context (Element (Position), Parents, Children);
-    end Context;
-
-
-
-
     ----------
     -- Copy --
     ----------
@@ -582,6 +609,29 @@ package body Directed_Graphs is
 
 
 
+    ---------------
+    -- Cursor_To --
+    ---------------
+
+    function Cursor_To
+           (Position : in Cursor;
+            Node     : in Node_Type)
+        return Cursor is
+    begin
+        if Impl.Checks then
+            if Position.Container = null then
+                raise Constraint_Error with "Graph does not exist";
+            end if;
+            if not Position.Container.Contains (Node) then
+                raise Constraint_Error with "Target node does not exist";
+            end if;
+        end if;
+        return Position.Container.To_Cursor (Node);
+    end Cursor_To;
+
+
+
+
     ------------
     -- Degree --
     ------------
@@ -685,6 +735,27 @@ package body Directed_Graphs is
     end Delete;
 
     procedure Delete
+           (Parent, Child : in out Cursor) is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+        end if;
+        declare
+            Edge : Edge_Type := (From => Element (Parent), To => Element (Child));
+        begin
+            Parent.Container.Delete (Edge);
+        end;
+    end Delete;
+
+    procedure Delete
            (Container : in out Graph;
             Edges     : in     Edge_Array) is
     begin
@@ -734,6 +805,27 @@ package body Directed_Graphs is
         Container.Edge_Labels.Delete (Edge);
     end Delete_Label;
 
+    procedure Delete_Label
+           (Parent, Child : in out Cursor) is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Edge (Parent, Child) then
+                raise Constraint_Error with "Graph does not contain edge";
+            end if;
+        end if;
+        Parent.Container.Delete_Label
+            ((From => Element (Parent), To => Element (Child)));
+    end Delete_Label;
+
 
 
 
@@ -1041,6 +1133,32 @@ package body Directed_Graphs is
 
 
 
+    ------------
+    -- Follow --
+    ------------
+
+    function Follow
+           (Position : in Cursor;
+            Edge     : in Edge_Type)
+        return Cursor is
+    begin
+        if Impl.Checks then
+            if Position.Container = null then
+                raise Constraint_Error with "Graph does not exist";
+            end if;
+            if not Has_Element (Position) then
+                raise Constraint_Error with "Cursor points to nothing";
+            end if;
+            if Element (Position) /= Edge.From then
+                raise Constraint_Error with "Cursor is not at tail of edge";
+            end if;
+        end if;
+        return Position.Container.To_Cursor (Edge.To);
+    end Follow;
+
+
+
+
     --------------
     -- Has_Edge --
     --------------
@@ -1137,6 +1255,31 @@ package body Directed_Graphs is
         return Container.Edge_Labels.Contains (Edge);
     end Has_Label;
 
+    function Has_Label
+           (Parent, Child : in Cursor)
+        return Boolean is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Element (Parent) then
+                raise Constraint_Error with "Parent cursor points to nothing";
+            end if;
+            if not Has_Element (Child) then
+                raise Constraint_Error with "Child cursor points to nothing";
+            end if;
+        end if;
+        return Parent.Container.Edge_Labels.Contains
+            ((From => Element (Parent), To => Element (Child)));
+    end Has_Label;
+
 
 
 
@@ -1361,6 +1504,38 @@ package body Directed_Graphs is
     end Insert;
 
     procedure Insert
+           (Parent, Child : in out Cursor) is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Element (Parent) then
+                raise Constraint_Error with "Parent cursor points to nothing";
+            end if;
+            if not Has_Element (Child) then
+                raise Constraint_Error with "Child cursor points to nothing";
+            end if;
+        end if;
+        Parent.Container.Connections.Reference (Element (Parent)).Append (Element (Child));
+    end Insert;
+
+    procedure Insert
+           (Parent, Child : in out Cursor;
+            Label         : in     Edge_Label_Type) is
+    begin
+        Insert (Parent, Child);
+        Parent.Container.Edge_Labels.Insert
+            ((From => Element (Parent), To => Element (Child)), Label);
+    end Insert;
+
+    procedure Insert
            (Container : in out Graph;
             Edges     : in     Edge_Array) is
     begin
@@ -1499,6 +1674,28 @@ package body Directed_Graphs is
         return Container.Edge_Labels.Element (Edge);
     end Label;
 
+    function Label
+           (Parent, Child : in Cursor)
+        return Edge_Label_Type is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Edge (Parent, Child) then
+                raise Constraint_Error with "Graph does not contain edge";
+            end if;
+        end if;
+        return Parent.Container.Edge_Labels.Element
+            ((From => Element (Parent), To => Element (Child)));
+    end Label;
+
 
 
 
@@ -1571,41 +1768,40 @@ package body Directed_Graphs is
         end;
     end Label_Reference;
 
-
-
-
-    ---------------------
-    -- Labeled_Context --
-    ---------------------
-
-    procedure Labeled_Context
-           (Container : in     Graph;
-            Node      : in     Node_Type;
-            Parents   :    out Node_Array;
-            Children  :    out Node_Array;
-            Label     :    out Node_Label_Type) is
-    begin
-        Parents := Container.Parents (Node);
-        Children := Container.Children (Node);
-        Label := Container.Label (Node);
-    end Labeled_Context;
-
-    procedure Labeled_Context
-           (Position : in     Cursor;
-            Parents  :    out Node_Array;
-            Children :    out Node_Array;
-            Label    :    out Node_Label_Type) is
+    function Label_Reference
+           (Parent, Child : in Cursor)
+        return Edge_Label_Reference is
     begin
         if Impl.Checks then
-            if Position.Container = null then
-                raise Constraint_Error with "Graph does not exist";
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
             end if;
-            if not Has_Element (Position) then
-                raise Constraint_Error with "Cursor points to nothing";
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors are for different graphs";
+            end if;
+            if not Has_Edge (Parent, Child) then
+                raise Constraint_Error with "Graph does not contain edge";
+            end if;
+            if not Has_Label (Parent, Child) then
+                raise Constraint_Error with "Edge does not have a label";
             end if;
         end if;
-        Position.Container.Labeled_Context (Element (Position), Parents, Children, Label);
-    end Labeled_Context;
+        declare
+            Tamper : constant Help.Tamper_Counts_Access :=
+                Parent.Container.Tamper_Info'Unrestricted_Access;
+            Edge : Edge_Type := ((From => Element (Parent), To => Element (Child)));
+        begin
+            return Ref : constant Edge_Label_Reference :=
+               (Element => Parent.Container.Edge_Labels.Reference (Edge).Element,
+                Control => (Ada.Finalization.Controlled with Tamper))
+            do
+                Impl.Lock (Tamper.all);
+            end return;
+        end;
+    end Label_Reference;
 
 
 
@@ -2176,6 +2372,28 @@ package body Directed_Graphs is
         Container.Edge_Labels.Replace (Edge, Label);
     end Replace_Label;
 
+    procedure Replace_Label
+           (Parent, Child : in out Cursor;
+            Label         : in     Edge_Label_Type) is
+    begin
+        if Impl.Checks then
+            if Parent.Container = null then
+                raise Constraint_Error with "Graph for parent cursor does not exist";
+            end if;
+            if Child.Container = null then
+                raise Constraint_Error with "Graph for child cursor does not exist";
+            end if;
+            if Parent.Container /= Child.Container then
+                raise Constraint_Error with "Cursors belong to different graphs";
+            end if;
+            if not Has_Edge (Parent, Child) then
+                raise Constraint_Error with "Graph does not contain edge";
+            end if;
+        end if;
+        Parent.Container.Edge_Labels.Replace
+            ((From => Element (Parent), To => Element (Child)), Label);
+    end Replace_Label;
+