Stamp/Ignore now Stamp/Discard/Ignore

4 files changed, 56 insertions, 3 deletions

diff --git a/src/packrat-lexers.adb b/src/packrat-lexers.adb
index 3a51e1a..bf5d109 100644
--- a/src/packrat-lexers.adb
+++ b/src/packrat-lexers.adb
@@ -363,7 +363,7 @@ package body Packrat.Lexers is
     end Stamp;
 
 
-    function Ignore
+    function Discard
            (Input   : in     Traits.Element_Array;
             Context : in out Lexer_Context)
         return Component_Result
@@ -402,7 +402,7 @@ package body Packrat.Lexers is
 
         Context.Error_Labels.Clear;
         return Component_Success;
-    end Ignore;
+    end Discard;
 
 
 
diff --git a/src/packrat-lexers.ads b/src/packrat-lexers.ads
index 9fd61e2..ac0ba2b 100644
--- a/src/packrat-lexers.ads
+++ b/src/packrat-lexers.ads
@@ -143,7 +143,7 @@ package Packrat.Lexers is
                (Input : in Traits.Element_Array;
                 Start : in Positive)
             return Combinator_Result;
-    function Ignore
+    function Discard
            (Input   : in     Traits.Element_Array;
             Context : in out Lexer_Context)
         return Component_Result;
diff --git a/src/packrat-parsers.adb b/src/packrat-parsers.adb
index e4fa97d..0ddd864 100644
--- a/src/packrat-parsers.adb
+++ b/src/packrat-parsers.adb
@@ -622,6 +622,46 @@ package body Packrat.Parsers is
     end Stamp;
 
 
+    function Discard
+           (Input   : in     Traits.Element_Array;
+            Context : in out Parser_Context;
+            Start   : in     Positive)
+        return Combinator_Result
+    is
+        function Actual
+               (Context : in out Parser_Context)
+            return Combinator_Result
+        is
+            Salt : Combinator_Result := Combo (Input, Context, Start);
+            Processed : Result_Sets.Set;
+        begin
+            if Salt.Status = Failure then
+                declare
+                    Error : String := Packrat.Errors.Encode
+                        (Traits.Label_Enum'Image (Label), Start);
+                begin
+                    if Ada.Strings.Unbounded.Index (Context.Error_String, Error) = 0 then
+                        Ada.Strings.Unbounded.Append (Context.Error_String, Error);
+                    end if;
+                end;
+                return Salt;
+            end if;
+            for R of Salt.Results loop
+                Processed.Include
+                   ((Finish => R.Finish,
+                     Value  => Elem_Holds.Empty_Holder,
+                     Tokens => Tok_Holds.Empty_Holder));
+            end loop;
+            Salt.Results := Processed;
+            return Salt;
+        end Actual;
+        function Memo is new Memoize (To_Key (Start, Discard'Access), Actual);
+        function Curt is new Curtailment (To_Key (Start, Discard'Access), Input, Memo);
+    begin
+        return Curt (Context);
+    end Discard;
+
+
     function Ignore
            (Input   : in     Traits.Element_Array;
             Context : in out Parser_Context;
diff --git a/src/packrat-parsers.ads b/src/packrat-parsers.ads
index e11d623..1e058dc 100644
--- a/src/packrat-parsers.ads
+++ b/src/packrat-parsers.ads
@@ -116,6 +116,19 @@ package Packrat.Parsers is
         return Combinator_Result;
 
     generic
+        Label : in Traits.Label_Enum;
+        with function Combo
+               (Input   : in     Traits.Element_Array;
+                Context : in out Parser_Context;
+                Start   : in     Positive)
+            return Combinator_Result;
+    function Discard
+           (Input   : in     Traits.Element_Array;
+            Context : in out Parser_Context;
+            Start   : in     Positive)
+        return Combinator_Result;
+
+    generic
         with function Combo
                (Input   : in     Traits.Element_Array;
                 Context : in out Parser_Context;