From 4c4a3b44a93c526aab44f1d1b3100e347b233acb Mon Sep 17 00:00:00 2001
From: Jed Barber <jjbarber@y7mail.com>
Date: Sun, 29 Nov 2020 21:10:36 +1100
Subject: Non-curtailing parser combinators implemented

---
 src/packrat-parsers.ads | 89 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 70 insertions(+), 19 deletions(-)

(limited to 'src/packrat-parsers.ads')

diff --git a/src/packrat-parsers.ads b/src/packrat-parsers.ads
index 8a0f39c..55cb12a 100644
--- a/src/packrat-parsers.ads
+++ b/src/packrat-parsers.ads
@@ -289,17 +289,7 @@ package Packrat.Parsers is
 
 
 
-    generic
-        EOL_Item : in Traits.Element_Type;
-    function Line_End
-           (Input   : in     Traits.Element_Array;
-            Context : in out Parser_Context;
-            Start   : in     Positive)
-        return Combinator_Result;
-
-    generic
-        EOF_Item : in Traits.Element_Type;
-    function Input_End
+    function Empty
            (Input   : in     Traits.Element_Array;
             Context : in out Parser_Context;
             Start   : in     Positive)
@@ -325,20 +315,20 @@ private
     --  for a given combinator/position
 
 
-    package Elem_Array_Holders is new Ada.Containers.Indefinite_Holders
+    package Elem_Holds is new Ada.Containers.Indefinite_Holders
        (Element_Type => Traits.Element_Array,
         "="          => Traits."=");
 
-    package Token_Array_Holders is new Ada.Containers.Indefinite_Holders
+    package Tok_Holds is new Ada.Containers.Indefinite_Holders
        (Element_Type => Traits.Tokens.Token_Array,
         "="          => Traits.Tokens."=");
 
     function "<"
-           (Left, Right : in Elem_Array_Holders.Holder)
+           (Left, Right : in Elem_Holds.Holder)
         return Boolean;
 
     function "<"
-           (Left, Right : in Token_Array_Holders.Holder)
+           (Left, Right : in Tok_Holds.Holder)
         return Boolean;
 
 
@@ -353,13 +343,24 @@ private
            (Left, Right : in Combo_Key)
         return Boolean;
 
+    --  This is needed to avoid some issues with using non-anonymous
+    --  access values in a generic subprogram instantiation.
+    function To_Key
+           (Start : in Positive;
+            Func  : access function
+                   (Input   : in     Traits.Element_Array;
+                    Context : in out Parser_Context;
+                    Start   : in     Positive)
+                return Combinator_Result)
+        return Combo_Key;
+
 
 
 
     type Combo_Result_Part is record
         Finish : Natural;
-        Value  : Elem_Array_Holders.Holder;
-        Tokens : Token_Array_Holders.Holder;
+        Value  : Elem_Holds.Holder;
+        Tokens : Tok_Holds.Holder;
     end record;
 
     function "<"
@@ -395,6 +396,11 @@ private
         Status : Result_Status;
     end record;
 
+    Empty_Fail : constant Combinator_Result :=
+       (Results  => Result_Sets.Empty_Set,
+        Curtails => Curtail_Maps.Empty_Map,
+        Status   => Failure);
+
 
 
 
@@ -414,7 +420,7 @@ private
         Position         : Positive := 1;
         Offset           : Natural := 0;
         Status           : Result_Status := Success;
-        Pass_Forward     : Elem_Array_Holders.Holder;
+        Pass_Forward     : Elem_Holds.Holder;
         Memotable        : Memotables.Map;
         Leftrectable     : Leftrectables.Map;
         Allow_Incomplete : Boolean := True;
@@ -425,12 +431,57 @@ private
         Position         => 1,
         Offset           => 0,
         Status           => Success,
-        Pass_Forward     => Elem_Array_Holders.Empty_Holder,
+        Pass_Forward     => Elem_Holds.Empty_Holder,
         Memotable        => Memotables.Empty_Map,
         Leftrectable     => Leftrectables.Empty_Map,
         Allow_Incomplete => True);
 
 
+
+
+    function Reusable
+           (Result   : in Combinator_Result;
+            Position : in Positive;
+            Leftrecs : in Leftrectables.Map)
+        return Boolean;
+
+    generic
+        My_Key : in Combo_Key;
+        with function Actual
+               (Context : in out Parser_Context)
+            return Combinator_Result;
+    function Memoize
+           (Context : in out Parser_Context)
+        return Combinator_Result;
+
+
+
+
+    procedure Inc_Leftrec
+           (Key     : in     Combo_Key;
+            Context : in out Parser_Context);
+
+    procedure Dec_Leftrec
+           (Key     : in     Combo_Key;
+            Context : in out Parser_Context);
+
+    function Exceeds_Curtail
+           (Key     : in Combo_Key;
+            Context : in Parser_Context;
+            Input   : in Traits.Element_Array)
+        return Boolean;
+
+    generic
+        My_Key : in Combo_Key;
+        Input  : in Traits.Element_Array;
+        with function Actual
+               (Context : in out Parser_Context)
+            return Combinator_Result;
+    function Curtailment
+           (Context : in out Parser_Context)
+        return Combinator_Result;
+
+
 end Packrat.Parsers;
 
 
-- 
cgit