Misc

2 files changed, 104 insertions, 65 deletions

diff --git a/src/packrat-graphs.adb b/src/packrat-graphs.adb
index f32c628..10e130f 100644
--- a/src/packrat-graphs.adb
+++ b/src/packrat-graphs.adb
@@ -1012,55 +1012,61 @@ package body Packrat.Graphs is
 
 
 
-    function Iterate
-           (This : in Graph)
-        return Graph_Iterators.Reversible_Iterator'Class is
-    begin
-        return Result : Reversible_Iterator do
-            Result.Position := No_Position;
-        end return;
-    end Iterate;
-
-
-    function Iterate_Subtree
-           (This     : in Graph;
-            Position : in Cursor)
-        return Graph_Iterators.Reversible_Iterator'Class is
+    function Default_Choices
+           (Container : in Graph;
+            Position  : in Cursor)
+        return Natural is
     begin
-        return Result : Reversible_Iterator do
-            Result.Position := No_Position;
-        end return;
-    end Iterate_Subtree;
+        if Is_Nothing (Position) then
+            return Container.Root_Count;
+        else
+            return Choices (Position);
+        end if;
+    end Default_Choices;
 
 
-    function Iterate_Choice
-           (This : in Graph;
-            Func : in Choosing_Function)
-        return Graph_Iterators.Forward_Iterator'Class is
+    function Accept_All
+           (Position : in Cursor)
+        return Boolean is
     begin
-        return Result : Forward_Iterator do
-            Result.Position := No_Position;
-        end return;
-    end Iterate_Choice;
+        return not Is_Nothing (Position);
+    end Accept_All;
 
 
 
 
 
-    function First
-           (Object : in Forward_Iterator)
-        return Cursor is
+    function Iterate
+           (Container : in Graph;
+            Start_At  : in Cursor := No_Position;
+            Choose    : in Choosing_Function := Default_Choices'Access;
+            Filter    : in Filter_Function := Accept_All'Access)
+        return Graph_Iterators.Reversible_Iterator'Class is
     begin
-        return No_Position;
-    end First;
+        return This : Reversible_Iterator do
+            This.My_Graph := Container'Unrestricted_Access;
+            This.Start_Pos := Start_At;
+            This.Rule := Specific_Branch;
+            This.Choose_Func := Choose;
+            This.Filter_Func := Filter;
+        end return;
+    end Iterate;
 
-    function Next
-           (Object : in Forward_Iterator;
-            Place  : in Cursor)
-        return Cursor is
+
+    function Iterate_All
+           (Container : in Graph;
+            Start_At  : in Cursor := No_Position;
+            Filter    : in Filter_Function := Accept_All'Access)
+        return Graph_Iterators.Reversible_Iterator'Class is
     begin
-        return No_Position;
-    end Next;
+        return This : Reversible_Iterator do
+            This.My_Graph := Container'Unrestricted_Access;
+            This.Start_Pos := Start_At;
+            This.Rule := All_Nodes;
+            This.Choose_Func := null;
+            This.Filter_Func := Filter;
+        end return;
+    end Iterate_All;
 
 
 
@@ -1070,7 +1076,18 @@ package body Packrat.Graphs is
            (Object : in Reversible_Iterator)
         return Cursor is
     begin
-        return No_Position;
+        if Object.My_Graph = null or else Object.My_Graph.all.Is_Empty then
+            return No_Position;
+        elsif Is_Nothing (Object.Start_Pos) then
+            if Object.Rule = All_Nodes then
+                return Object.My_Graph.all.Root (1);
+            else
+                return Object.My_Graph.all.Root
+                   (Object.Choose_Func (Object.My_Graph.all, No_Position));
+            end if;
+        else
+            return Object.Start_Pos;
+        end if;
     end First;
 
 
@@ -1079,6 +1096,12 @@ package body Packrat.Graphs is
             Place  : in Cursor)
         return Cursor is
     begin
+        if  Object.My_Graph = null or else
+            Object.My_Graph.all.Is_Empty or else
+            Is_Nothing (Place)
+        then
+            return No_Position;
+        end if;  --  elsif
         return No_Position;
     end Next;
 
diff --git a/src/packrat-graphs.ads b/src/packrat-graphs.ads
index 5074485..6bceaaf 100644
--- a/src/packrat-graphs.ads
+++ b/src/packrat-graphs.ads
@@ -387,26 +387,52 @@ package Packrat.Graphs is
     package Graph_Iterators is
         new Ada.Iterator_Interfaces (Cursor, Is_Node);
 
+    --  Note that if the given Cursor doesn't point to any position,
+    --  then the function should assume that the choice is of what root to
+    --  select and return that value.
     type Choosing_Function is access function
+           (Container : in Graph;
+            Position  : in Cursor)
+        return Natural;
+
+    --  This function returns True if a Node pointed to by a Cursor should
+    --  be returned, and False if it should be ignored. An example of a
+    --  filter that will probably see a decent amount of use would be Is_Leaf.
+    type Filter_Function is access function
            (Position : in Cursor)
+        return Boolean;
+
+
+
+
+    function Default_Choices
+           (Container : in Graph;
+            Position  : in Cursor)
         return Natural;
 
+    function Accept_All
+           (Position : in Cursor)
+        return Boolean;
 
 
 
-    function Iterate
-           (This : in Graph)
-        return Graph_Iterators.Reversible_Iterator'Class;
 
-    function Iterate_Subtree
-           (This     : in Graph;
-            Position : in Cursor)
-        return Graph_Iterators.Reversible_Iterator'Class;
+    function Iterate
+           (Container : in Graph;
+            Start_At  : in Cursor := No_Position;
+            Choose    : in Choosing_Function := Default_Choices'Access;
+            Filter    : in Filter_Function := Accept_All'Access)
+        return Graph_Iterators.Reversible_Iterator'Class
+    with Pre =>
+            Container.Contains (Start_At) or Is_Nothing (Start_At);
 
-    function Iterate_Choice
-           (This : in Graph;
-            Func : in Choosing_Function)
-        return Graph_Iterators.Forward_Iterator'Class;
+    function Iterate_All
+           (Container : in Graph;
+            Start_At  : in Cursor := No_Position;
+            Filter    : in Filter_Function := Accept_All'Access)
+        return Graph_Iterators.Reversible_Iterator'Class
+    with Pre =>
+            Container.Contains (Start_At) or Is_Nothing (Start_At);
 
 
 
@@ -597,24 +623,14 @@ private
 
 
 
-    type Forward_Iterator is new Graph_Iterators.Forward_Iterator with record
-        Position : Cursor;
-    end record;
-
-    overriding function First
-           (Object : in Forward_Iterator)
-        return Cursor;
-
-    overriding function Next
-           (Object : in Forward_Iterator;
-            Place  : in Cursor)
-        return Cursor;
-
-
-
+    type Iterate_Kind is (Specific_Branch, All_Nodes);
 
     type Reversible_Iterator is new Graph_Iterators.Reversible_Iterator with record
-        Position : Cursor;
+        My_Graph    : access Graph;
+        Start_Pos   : Cursor;
+        Rule        : Iterate_Kind;
+        Choose_Func : Choosing_Function;
+        Filter_Func : Filter_Function;
     end record;
 
     overriding function First