AST refactoring

ASTPlayground/ASTPlayground.dpr

@@ -5,7 +5,10 @@ uses
     FMX.Forms,
     MainForm in 'MainForm.pas' {Form1},
     Myc.Ast.Evaluator in '..\Src\AST\Myc.Ast.Evaluator.pas',
-    Myc.Ast.Printer in '..\Src\AST\Myc.Ast.Printer.pas';
+    Myc.Ast.Printer in '..\Src\AST\Myc.Ast.Printer.pas',
+    Myc.Ast.Types in '..\Src\AST\Myc.Ast.Types.pas',
+    Myc.Ast.Scope in '..\Src\AST\Myc.Ast.Scope.pas',
+    Myc.Ast.Closure in '..\Src\AST\Myc.Ast.Closure.pas';
 
 {$R *.res}
 

ASTPlayground/ASTPlayground.dproj

@@ -70,7 +70,7 @@
         <Icon_MainIcon>$(BDS)\bin\delphi_PROJECTICON.ico</Icon_MainIcon>
         <Icns_MainIcns>$(BDS)\bin\delphi_PROJECTICNS.icns</Icns_MainIcns>
         <SanitizedProjectName>ASTPlayground</SanitizedProjectName>
-        <DCC_UnitSearchPath>T:\Myc\Src\Data;T:\Myc\Src\AST;$(DCC_UnitSearchPath)</DCC_UnitSearchPath>
+        <DCC_UnitSearchPath>T:\Myc\Src\Data;T:\Myc\Src\AST;T:\Myc\Src;$(DCC_UnitSearchPath)</DCC_UnitSearchPath>
         <VerInfo_Locale>1031</VerInfo_Locale>
         <VerInfo_Keys>CompanyName=;FileDescription=$(MSBuildProjectName);FileVersion=1.0.0.0;InternalName=;LegalCopyright=;LegalTrademarks=;OriginalFilename=;ProgramID=com.embarcadero.$(MSBuildProjectName);ProductName=$(MSBuildProjectName);ProductVersion=1.0.0.0;Comments=</VerInfo_Keys>
     </PropertyGroup>
@@ -137,6 +137,9 @@
         </DCCReference>
         <DCCReference Include="..\Src\AST\Myc.Ast.Evaluator.pas"/>
         <DCCReference Include="..\Src\AST\Myc.Ast.Printer.pas"/>
+        <DCCReference Include="..\Src\AST\Myc.Ast.Types.pas"/>
+        <DCCReference Include="..\Src\AST\Myc.Ast.Scope.pas"/>
+        <DCCReference Include="..\Src\AST\Myc.Ast.Closure.pas"/>
         <BuildConfiguration Include="Base">
             <Key>Base</Key>
         </BuildConfiguration>

ASTPlayground/MainForm.pas

@@ -20,6 +20,7 @@ uses
     FMX.Controls.Presentation,
     Myc.Data.Types,
     Myc.Ast,
+    Myc.Ast.Scope,
     Myc.Ast.Evaluator,
     Myc.Ast.Printer;
 

Src/AST/Myc.Ast.Closure.pas

@@ -0,0 +1,124 @@
+unit Myc.Ast.Closure;
+
+interface
+
+uses
+    System.Classes,
+    System.Generics.Collections,
+    Myc.Data.Types,
+    Myc.Ast,
+    Myc.Ast.Scope;
+
+type
+    // A closure is a specific kind of method value that is defined by the evaluator.
+    // It holds the AST body and its captured scope.
+    IDataClosureValue = interface(IDataMethodValue)
+        ['{2704586B-E4BD-47AA-B05D-FD441AE6D818}']
+        {$region 'private'}
+        function GetBody: IExpressionNode;
+        function GetParameters: TList<IIdentifierNode>;
+        function GetClosureScope: TExecutionScope;
+        {$endregion}
+        property Body: IExpressionNode read GetBody;
+        property Parameters: TList<IIdentifierNode> read GetParameters;
+        property ClosureScope: TExecutionScope read GetClosureScope;
+    end;
+
+// Factory function to create a new closure value.
+function CreateDataClosureValue(
+    AMethodType: IDataMethodType;
+    ABody: IExpressionNode;
+    AParameters: TList<IIdentifierNode>;
+    AClosureScope: TExecutionScope
+): IDataClosureValue;
+
+implementation
+
+uses
+    System.SysUtils;
+
+type
+    { TDataClosureValueImpl }
+    // Concrete implementation of the IDataClosureValue interface.
+    TDataClosureValueImpl = class(TInterfacedObject, IDataValue, IDataClosureValue)
+    private
+        FMethodType: IDataMethodType;
+        FBody: IExpressionNode;
+        FParameters: TList<IIdentifierNode>;
+        FClosureScope: TExecutionScope;
+        // IDataValue
+        function GetDataType: IDataType;
+        function GetAsString: string;
+        // IDataMethodValue
+        function GetValue: TDataMethodProc;
+        // IDataClosureValue
+        function GetBody: IExpressionNode;
+        function GetParameters: TList<IIdentifierNode>;
+        function GetClosureScope: TExecutionScope;
+    public
+        constructor Create(
+            AMethodType: IDataMethodType;
+            ABody: IExpressionNode;
+            AParameters: TList<IIdentifierNode>;
+            ACClosureScope: TExecutionScope
+        );
+    end;
+
+function CreateDataClosureValue(
+    AMethodType: IDataMethodType;
+    ABody: IExpressionNode;
+    AParameters: TList<IIdentifierNode>;
+    AClosureScope: TExecutionScope
+): IDataClosureValue;
+begin
+    Result := TDataClosureValueImpl.Create(AMethodType, ABody, AParameters, AClosureScope);
+end;
+
+{ TDataClosureValueImpl }
+
+constructor TDataClosureValueImpl.Create(
+    AMethodType: IDataMethodType;
+    ABody: IExpressionNode;
+    AParameters: TList<IIdentifierNode>;
+    ACClosureScope: TExecutionScope
+);
+begin
+    inherited Create;
+    FMethodType := AMethodType;
+    FBody := ABody;
+    FParameters := AParameters; // Note: We are taking ownership of the list reference
+    FClosureScope := ACClosureScope;
+end;
+
+function TDataClosureValueImpl.GetAsString: string;
+begin
+    Result := '<CLOSURE>';
+end;
+
+function TDataClosureValueImpl.GetBody: IExpressionNode;
+begin
+    Result := FBody;
+end;
+
+function TDataClosureValueImpl.GetClosureScope: TExecutionScope;
+begin
+    Result := FClosureScope;
+end;
+
+function TDataClosureValueImpl.GetDataType: IDataType;
+begin
+    Result := FMethodType;
+end;
+
+function TDataClosureValueImpl.GetParameters: TList<IIdentifierNode>;
+begin
+    Result := FParameters;
+end;
+
+function TDataClosureValueImpl.GetValue: TDataMethodProc;
+begin
+    // This direct execution path is no longer used for closures.
+    raise ENotSupportedException.Create('Cannot get raw method proc from a closure object.');
+end;
+
+end.

Src/AST/Myc.Ast.Evaluator.pas

@@ -1,5 +1,3 @@
-// https://g.co/gemini/share/f8965e72f968
-
 unit Myc.Ast.Evaluator;
 
 interface
@@ -9,39 +7,11 @@ uses
     System.Classes, // For TStrings
     System.Generics.Collections,
     Myc.Data.Types,
-    Myc.Ast;
+    Myc.Ast,
+    Myc.Ast.Scope,
+    Myc.Ast.Closure;
 
 type
-    // Manages the scope of execution, holding variables and their values.
-    TExecutionScope = class
-    private
-        FParent: TExecutionScope;
-        FVariables: TDictionary<string, IDataValue>;
-        // Added for recursive dumping
-        procedure DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
-    public
-        constructor Create(AParent: TExecutionScope = nil);
-        destructor Destroy; override;
-        function FindValue(const Name: string; out Value: IDataValue): Boolean;
-        procedure SetValue(const Name: string; const Value: IDataValue);
-        // Dumps the content of this scope and all parent scopes to a string.
-        function Dump: string;
-    end;
-
-    // A closure is a specific kind of method value that is defined by the evaluator.
-    // It holds the AST body and its captured scope.
-    IDataClosureValue = interface(IDataMethodValue)
-        ['{2704586B-E4BD-47AA-B05D-FD441AE6D818}']
-        {$region 'private'}
-        function GetBody: IExpressionNode;
-        function GetParameters: TList<IIdentifierNode>;
-        function GetClosureScope: TExecutionScope;
-        {$endregion}
-        property Body: IExpressionNode read GetBody;
-        property Parameters: TList<IIdentifierNode> read GetParameters;
-        property ClosureScope: TExecutionScope read GetClosureScope;
-    end;
-
     // TEvaluatorVisitor is the base implementation for evaluating an AST.
     TEvaluatorVisitor = class(TInterfacedObject, IAstVisitor)
     protected // Changed to protected to be accessible by descendants
@@ -91,145 +61,6 @@ type
 
 implementation
 
-type
-    { TDataClosureValueImpl }
-    // Concrete implementation of the IDataClosureValue interface.
-    TDataClosureValueImpl = class(TInterfacedObject, IDataValue, IDataClosureValue)
-    private
-        FMethodType: IDataMethodType;
-        FBody: IExpressionNode;
-        FParameters: TList<IIdentifierNode>;
-        FClosureScope: TExecutionScope;
-        // IDataValue
-        function GetDataType: IDataType;
-        function GetAsString: string;
-        // IDataMethodValue
-        function GetValue: TDataMethodProc;
-        // IDataClosureValue
-        function GetBody: IExpressionNode;
-        function GetParameters: TList<IIdentifierNode>;
-        function GetClosureScope: TExecutionScope;
-    public
-        constructor Create(
-            AMethodType: IDataMethodType;
-            ABody: IExpressionNode;
-            AParameters: TList<IIdentifierNode>;
-            ACClosureScope: TExecutionScope
-        );
-    end;
-
-constructor TDataClosureValueImpl.Create(
-    AMethodType: IDataMethodType;
-    ABody: IExpressionNode;
-    AParameters: TList<IIdentifierNode>;
-    ACClosureScope: TExecutionScope
-);
-begin
-    inherited Create;
-    FMethodType := AMethodType;
-    FBody := ABody;
-    FParameters := AParameters; // Note: We are taking ownership of the list reference
-    FClosureScope := ACClosureScope;
-end;
-
-function TDataClosureValueImpl.GetAsString: string;
-begin
-    Result := '<CLOSURE>';
-end;
-
-function TDataClosureValueImpl.GetBody: IExpressionNode;
-begin
-    Result := FBody;
-end;
-
-function TDataClosureValueImpl.GetClosureScope: TExecutionScope;
-begin
-    Result := FClosureScope;
-end;
-
-function TDataClosureValueImpl.GetDataType: IDataType;
-begin
-    Result := FMethodType;
-end;
-
-function TDataClosureValueImpl.GetParameters: TList<IIdentifierNode>;
-begin
-    Result := FParameters;
-end;
-
-function TDataClosureValueImpl.GetValue: TDataMethodProc;
-begin
-    // This direct execution path is no longer used for closures.
-    raise ENotSupportedException.Create('Cannot get raw method proc from a closure object.');
-end;
-
-{ TExecutionScope }
-
-constructor TExecutionScope.Create(AParent: TExecutionScope = nil);
-begin
-    inherited Create;
-    FParent := AParent;
-    FVariables := TDictionary<string, IDataValue>.Create;
-end;
-
-destructor TExecutionScope.Destroy;
-begin
-    FVariables.Free;
-    inherited Destroy;
-end;
-
-procedure TExecutionScope.DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
-var
-    pair: TPair<string, IDataValue>;
-    indentStr: string;
-begin
-    indentStr := ''.PadLeft(AIndent);
-    if FVariables.Count > 0 then
-    begin
-        for pair in FVariables do
-            ABuilder.AppendLine(indentStr + Format('  %s: %s', [pair.Key, pair.Value.AsString]));
-    end
-    else
-    begin
-        ABuilder.AppendLine(indentStr + '  (empty)');
-    end;
-
-    if Assigned(FParent) then
-    begin
-        ABuilder.AppendLine(indentStr + '[Parent Scope]');
-        FParent.DumpScope(ABuilder, AIndent + 2);
-    end;
-end;
-
-function TExecutionScope.Dump: string;
-var
-    builder: TStringBuilder;
-begin
-    builder := TStringBuilder.Create;
-    try
-        builder.AppendLine('[Current Scope]');
-        DumpScope(builder, 0);
-        Result := builder.ToString.TrimRight;
-    finally
-        builder.Free;
-    end;
-end;
-
-function TExecutionScope.FindValue(const Name: string; out Value: IDataValue): Boolean;
-begin
-    Result := FVariables.TryGetValue(Name, Value);
-    if not Result and Assigned(FParent) then
-    begin
-        Result := FParent.FindValue(Name, Value);
-    end;
-end;
-
-procedure TExecutionScope.SetValue(const Name: string; const Value: IDataValue);
-begin
-    // This defines a variable in the current scope. It can shadow a parent variable.
-    FVariables.AddOrSetValue(Name, Value);
-end;
-
 { TEvaluatorVisitor }
 
 constructor TEvaluatorVisitor.Create(AScope: TExecutionScope);
@@ -252,7 +83,8 @@ begin
     // Instead of creating an anonymous method, we now create a data object
     // that holds all information required to execute the lambda later.
     methodType := TDataType.MethodOf(TDataType.Ordinal, TDataType.Ordinal); // TODO: Infer this
-    Result := TDataClosureValueImpl.Create(methodType, Node.Body, Node.Parameters, FScope);
+    // Use the factory function from the Myc.Ast.Closure unit.
+    Result := CreateDataClosureValue(methodType, Node.Body, Node.Parameters, FScope);
 end;
 
 function TEvaluatorVisitor.VisitFunctionCall(const Node: IFunctionCallNode): IDataValue;

Src/AST/Myc.Ast.Scope.pas

@@ -0,0 +1,97 @@
+unit Myc.Ast.Scope;
+
+interface
+
+uses
+    System.SysUtils,
+    System.Classes,
+    System.Generics.Collections,
+    Myc.Data.Types;
+
+type
+    // Manages the scope of execution, holding variables and their values.
+    TExecutionScope = class
+    private
+        FParent: TExecutionScope;
+        FVariables: TDictionary<string, IDataValue>;
+        // Added for recursive dumping
+        procedure DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
+    public
+        constructor Create(AParent: TExecutionScope = nil);
+        destructor Destroy; override;
+        function FindValue(const Name: string; out Value: IDataValue): Boolean;
+        procedure SetValue(const Name: string; const Value: IDataValue);
+        // Dumps the content of this scope and all parent scopes to a string.
+        function Dump: string;
+    end;
+
+implementation
+
+{ TExecutionScope }
+
+constructor TExecutionScope.Create(AParent: TExecutionScope = nil);
+begin
+    inherited Create;
+    FParent := AParent;
+    FVariables := TDictionary<string, IDataValue>.Create;
+end;
+
+destructor TExecutionScope.Destroy;
+begin
+    FVariables.Free;
+    inherited Destroy;
+end;
+
+procedure TExecutionScope.DumpScope(const ABuilder: TStringBuilder; AIndent: Integer);
+var
+    pair: TPair<string, IDataValue>;
+    indentStr: string;
+begin
+    indentStr := ''.PadLeft(AIndent);
+    if (FVariables.Count > 0) then
+    begin
+        for pair in FVariables do
+            ABuilder.AppendLine(indentStr + Format('  %s: %s', [pair.Key, pair.Value.AsString]));
+    end
+    else
+    begin
+        ABuilder.AppendLine(indentStr + '  (empty)');
+    end;
+
+    if Assigned(FParent) then
+    begin
+        ABuilder.AppendLine(indentStr + '[Parent Scope]');
+        FParent.DumpScope(ABuilder, AIndent + 2);
+    end;
+end;
+
+function TExecutionScope.Dump: string;
+var
+    builder: TStringBuilder;
+begin
+    builder := TStringBuilder.Create;
+    try
+        builder.AppendLine('[Current Scope]');
+        DumpScope(builder, 0);
+        Result := builder.ToString.TrimRight;
+    finally
+        builder.Free;
+    end;
+end;
+
+function TExecutionScope.FindValue(const Name: string; out Value: IDataValue): Boolean;
+begin
+    Result := FVariables.TryGetValue(Name, Value);
+    if not Result and Assigned(FParent) then
+    begin
+        Result := FParent.FindValue(Name, Value);
+    end;
+end;
+
+procedure TExecutionScope.SetValue(const Name: string; const Value: IDataValue);
+begin
+    // This defines a variable in the current scope. It can shadow a parent variable.
+    FVariables.AddOrSetValue(Name, Value);
+end;
+
+end.