Keywords

ASTPlayground/ASTPlayground.dpr

@@ -20,7 +20,8 @@ uses
     Myc.Fmx.AstEditor.Text in 'Myc.Fmx.AstEditor.Text.pas',
     Myc.Utils in '..\Src\Myc.Utils.pas',
     Myc.Ast.Script in '..\Src\AST\Myc.Ast.Script.pas',
-    Myc.Ast.Types in '..\Src\AST\Myc.Ast.Types.pas';
+    Myc.Ast.Types in '..\Src\AST\Myc.Ast.Types.pas',
+    Myc.Data.Keyword in '..\Src\Data\Myc.Data.Keyword.pas';
 
 {$R *.res}
 

ASTPlayground/ASTPlayground.dproj

@@ -151,6 +151,7 @@
         <DCCReference Include="..\Src\Myc.Utils.pas"/>
         <DCCReference Include="..\Src\AST\Myc.Ast.Script.pas"/>
         <DCCReference Include="..\Src\AST\Myc.Ast.Types.pas"/>
+        <DCCReference Include="..\Src\Data\Myc.Data.Keyword.pas"/>
         <BuildConfiguration Include="Base">
             <Key>Base</Key>
         </BuildConfiguration>

Src/AST/Myc.Ast.RTL.Core.pas

@@ -297,7 +297,7 @@ begin
 
             key := argScalar.Value.AsInt64;
 
-            var cache := cCache.AsObject as TDictionary<Int64, TDataValue>;
+            var cache := TDictionary<Int64, TDataValue>(cCache.AsObject);
 
             if cache.TryGetValue(key, Result) then
                 exit;

Src/Data/Myc.Data.Keyword.pas

@@ -0,0 +1,83 @@
+unit Myc.Data.Keyword;
+
+interface
+
+uses
+    System.SysUtils,
+    System.Classes,
+    System.Generics.Collections,
+    System.SyncObjs;
+
+type
+    // The runtime representation of an interned keyword
+    IKeyword = interface(IInterface)
+        function GetName: string;
+        property Name: string read GetName;
+    end;
+
+    // Factory and registry for all keywords (Flyweight Pattern)
+    TKeywordRegistry = record
+    strict private
+        type
+            TKeyword = class(TInterfacedObject, IKeyword)
+            private
+                FName: string;
+                function GetName: string;
+            public
+                constructor Create(const AName: string);
+            end;
+    strict private
+        class var
+            FLock: TSpinLock;
+        class var
+            FRegistry: TDictionary<string, IKeyword>;
+        class constructor Create;
+        class destructor Destroy;
+    public
+        // Gets or creates the interned keyword for the given name.
+        class function Intern(const AName: string): IKeyword; static;
+    end;
+
+implementation
+
+{ TKeywordRegistry.TKeyword }
+
+constructor TKeywordRegistry.TKeyword.Create(const AName: string);
+begin
+    inherited Create;
+    FName := AName;
+end;
+
+function TKeywordRegistry.TKeyword.GetName: string;
+begin
+    Result := FName;
+end;
+
+{ TKeywordRegistry }
+
+class constructor TKeywordRegistry.Create;
+begin
+    FLock := TSpinLock.Create(false);
+    FRegistry := TDictionary<string, IKeyword>.Create;
+end;
+
+class destructor TKeywordRegistry.Destroy;
+begin
+    FRegistry.Free;
+end;
+
+class function TKeywordRegistry.Intern(const AName: string): IKeyword;
+begin
+    FLock.Enter;
+    try
+        if not FRegistry.TryGetValue(AName, Result) then
+        begin
+            Result := TKeyword.Create(AName);
+            FRegistry.Add(AName, Result);
+        end;
+    finally
+        FLock.Exit;
+    end;
+end;
+
+end.

Src/Data/Myc.Data.Value.pas

@@ -7,11 +7,24 @@ uses
     System.SyncObjs,
     Myc.Utils,
     Myc.Data.Scalar,
-    Myc.Data.Series;
+    Myc.Data.Series,
+    Myc.Data.Keyword;
 
 type
-    TDataValueKind =
+    TDataValueKind = (
-        (vkVoid, vkScalar, vkText, vkSeries, vkRecordSeries, vkRecord, vkManagedObject, vkMethod, vkInterface, vkPointer, vkGeneric);
+        vkVoid,
+        vkScalar,
+        vkText,
+        vkKeyword,
+        vkSeries,
+        vkRecordSeries,
+        vkRecord,
+        vkManagedObject,
+        vkMethod,
+        vkInterface,
+        vkPointer,
+        vkGeneric
+    );
 
     TDataValue = record
         type
@@ -47,6 +60,7 @@ type
         class operator Implicit(const AValue: TScalar): TDataValue; overload; inline;
         class operator Implicit(const AValue: TDataValue): TScalar; overload; inline;
         class operator Implicit(const AValue: String): TDataValue; overload; inline;
+        class operator Implicit(const AValue: IKeyword): TDataValue; overload; inline;
         class operator Implicit(const AValue: TDataValue.TFunc): TDataValue; overload; inline;
         class operator Implicit(const AValue: TObject): TDataValue; overload; inline;
 
@@ -68,10 +82,12 @@ type
         class function FromRecordSeries(const AValue: IRecordSeries): TDataValue; static; inline;
         class function FromRecord(const [ref] AValue: TScalarRecord): TDataValue; static; inline;
         class function FromSeries(const AValue: ISeries): TDataValue; static; inline;
+        class function FromKeyword(const AValue: IKeyword): TDataValue; static; inline; // Added
 
         function AsScalar: TScalar; inline;
         function AsMethod: TFunc; inline;
         function AsText: String; inline;
+        function AsKeyword: IKeyword; inline; // Added
         function AsRecordSeries: IRecordSeries; inline;
         function AsRecord: TScalarRecord; inline;
         function AsSeries: ISeries; inline;
@@ -171,6 +187,13 @@ begin
     Result := Pointer(FScalar.Value.AsInt64);
 end;
 
+function TDataValue.AsKeyword: IKeyword;
+begin
+    if (FKind <> vkKeyword) then
+        raise EInvalidCast.Create('Cannot read value as Keyword.');
+    Result := IKeyword(FInterface);
+end;
+
 function TDataValue.AsRecord: TScalarRecord;
 begin
     if (FKind <> vkRecord) then
@@ -241,7 +264,7 @@ begin
                 TInterlocked.CompareExchange(FScalar.Value.AsInt64, NewValue.AsScalar.Value.AsInt64, Expected.AsScalar.Value.AsInt64)
                     = Expected.AsScalar.Value.AsInt64;
 
-        vkText, vkSeries, vkRecordSeries, vkRecord, vkManagedObject, vkMethod, vkInterface, vkGeneric:
+        vkText, vkKeyword, vkSeries, vkRecordSeries, vkRecord, vkManagedObject, vkMethod, vkInterface, vkGeneric: // Added vkKeyword
             Result := IntfCompareExchange(FInterface, NewValue.FInterface, Expected.FInterface) = Expected.FInterface;
     end;
 end;
@@ -258,6 +281,12 @@ begin
     Result.FInterface := TVal<T>.Create(AValue);
 end;
 
+class function TDataValue.FromKeyword(const AValue: IKeyword): TDataValue;
+begin
+    Result.FKind := vkKeyword;
+    Result.FInterface := AValue;
+end;
+
 class function TDataValue.FromPtr(const AValue: Pointer): TDataValue;
 begin
     Assert(sizeof(Pointer) <= sizeof(Int64));
@@ -296,6 +325,12 @@ begin
     Result.FInterface := TVal<String>.Create(AValue);
 end;
 
+class operator TDataValue.Implicit(const AValue: IKeyword): TDataValue;
+begin
+    Result.FKind := vkKeyword;
+    Result.FInterface := AValue;
+end;
+
 function TDataValue.GetIsVoid: Boolean;
 begin
     Result := FKind = vkVoid;
@@ -334,7 +369,7 @@ begin
             end;
         vkPointer: Result := TInterlocked.Exchange(FScalar.Value.AsInt64, NewValue.AsScalar.Value.AsInt64);
 
-        vkText, vkSeries, vkRecordSeries, vkRecord, vkManagedObject, vkMethod, vkInterface, vkGeneric:
+        vkText, vkKeyword, vkSeries, vkRecordSeries, vkRecord, vkManagedObject, vkMethod, vkInterface, vkGeneric: // Added vkKeyword
         begin
             Result.FKind := FKind;
             Result.FInterface := IntfExchange(FInterface, NewValue.FInterface);
@@ -351,6 +386,7 @@ begin
     case FKind of
         vkScalar: Result := FScalar.ToString;
         vkText: Result := '"' + AsText + '"';
+        vkKeyword: Result := ':' + AsKeyword.Name; // Added
         vkSeries:
         begin
             var series := AsSeries;
@@ -454,6 +490,7 @@ begin
         vkVoid: Result := 'Void';
         vkScalar: Result := 'Scalar';
         vkText: Result := 'Text';
+        vkKeyword: Result := 'Keyword'; // Added
         vkSeries: Result := 'Series';
         vkRecordSeries: Result := 'RecordSeries';
         vkRecord: Result := 'Record';