Keywords

Src/AST/Myc.Ast.Script.pas

@@ -24,6 +24,7 @@ uses
     System.Math,
     Myc.Data.Scalar,
     Myc.Data.Value,
+    Myc.Data.Keyword,
     Myc.Ast;
 
 type
@@ -35,11 +36,14 @@ type
         tkRightParen, // )
         tkLeftBracket, // [
         tkRightBracket, // ]
+        tkLeftBrace, // {
+        tkRightBrace, // }
         tkQuote, // '
         tkBacktick, // `
         tkTilde, // ~
         tkAt, // @
         tkIdentifier,
+        tkKeyword,
         tkNumber,
         tkString,
         tkEOF,
@@ -82,6 +86,7 @@ type
         procedure Consume(AExpectedKind: TTokenKind);
         procedure NextToken;
         function ParseList: IAstNode;
+        function ParseRecordLiteral: IAstNode;
         function ParseParameterList: TArray<IIdentifierNode>;
         function ParseExpression: TExpr;
     public
@@ -108,6 +113,7 @@ type
         function Execute(const RootNode: IAstNode): TDataValue;
         function VisitConstant(const Node: IConstantNode): TDataValue; override;
         function VisitIdentifier(const Node: IIdentifierNode): TDataValue; override;
+        function VisitKeyword(const Node: IKeywordNode): TDataValue; override;
         function VisitBinaryExpression(const Node: IBinaryExpressionNode): TDataValue; override;
         function VisitUnaryExpression(const Node: IUnaryExpressionNode): TDataValue; override;
         function VisitIfExpression(const Node: IIfExpressionNode): TDataValue; override;
@@ -124,6 +130,7 @@ type
         function VisitAssignment(const Node: IAssignmentNode): TDataValue; override;
         function VisitIndexer(const Node: IIndexerNode): TDataValue; override;
         function VisitMemberAccess(const Node: IMemberAccessNode): TDataValue; override;
+        function VisitRecordLiteral(const Node: IRecordLiteralNode): TDataValue; override;
         function VisitCreateSeries(const Node: ICreateSeriesNode): TDataValue; override;
         function VisitAddSeriesItem(const Node: IAddSeriesItemNode): TDataValue; override;
         function VisitSeriesLength(const Node: ISeriesLengthNode): TDataValue; override;
@@ -158,7 +165,7 @@ var
 begin
     startPos := FCurrentPos;
     // Reader macro characters are now also delimiters for identifiers.
-    while (Peek <> #0) and (not (Peek.IsWhiteSpace or CharInSet(Peek, ['(', ')', '[', ']', '''', '`', '~']))) do
+    while (Peek <> #0) and (not (Peek.IsWhiteSpace or CharInSet(Peek, ['(', ')', '[', ']', '{', '}', '''', '`', '~']))) do
         Advance;
     Result := Copy(FSource, startPos, FCurrentPos - startPos);
 end;
@@ -237,6 +244,16 @@ begin
             Result.Kind := tkRightBracket;
             Advance;
         end;
+        '{':
+        begin
+            Result.Kind := tkLeftBrace;
+            Advance;
+        end;
+        '}':
+        begin
+            Result.Kind := tkRightBrace;
+            Advance;
+        end;
         '''':
         begin
             Result.Kind := tkQuote;
@@ -262,6 +279,14 @@ begin
             Result.Kind := tkString;
             Result.Text := ReadString;
         end;
+        ':':
+        begin
+            Advance; // Skip :
+            Result.Kind := tkKeyword;
+            Result.Text := ReadIdentifier;
+            if Result.Text.IsEmpty then
+                Result.Kind := tkError;
+        end;
     else
         if c.IsDigit or ((c = '-') and (FCurrentPos < Length(FSource)) and FSource[FCurrentPos + 1].IsDigit) then
         begin
@@ -326,6 +351,41 @@ begin
     Consume(tkRightBracket);
 end;
 
+function TParser.ParseRecordLiteral: IAstNode;
+var
+    fields: TList<TRecordFieldLiteral>;
+    fieldName: string;
+    fieldValue: IAstNode;
+begin
+    Consume(tkLeftBrace);
+    fields := TList<TRecordFieldLiteral>.Create;
+    try
+        while FCurrentToken.Kind <> tkRightBrace do
+        begin
+            if FCurrentToken.Kind = tkEOF then
+                raise Exception.Create('Syntax Error: Unexpected end of file in record literal.');
+
+            // Key must be a keyword
+            if FCurrentToken.Kind <> tkKeyword then
+                raise Exception.Create('Syntax Error: Expected keyword (e.g., :key) as field name in record literal.');
+            fieldName := FCurrentToken.Text;
+            NextToken;
+
+            // Value can be any expression
+            if FCurrentToken.Kind = tkRightBrace then
+                raise Exception.Create('Syntax Error: Missing value for key ' + fieldName + ' in record literal.');
+            fieldValue := ParseExpression.Node;
+
+            fields.Add(TRecordFieldLiteral.Create(fieldName, fieldValue));
+        end;
+
+        Result := TAst.RecordLiteral(fields.ToArray);
+    finally
+        fields.Free;
+    end;
+    Consume(tkRightBrace);
+end;
+
 function TParser.ParseList: IAstNode;
 
 var
@@ -504,6 +564,11 @@ begin
             Result.Node := TAst.Constant(FCurrentToken.Text);
             NextToken;
         end;
+        tkKeyword:
+        begin
+            Result.Node := TAst.Keyword(FCurrentToken.Text);
+            NextToken;
+        end;
         tkIdentifier:
         begin
             Result.Node := TAst.Identifier(FCurrentToken.Text);
@@ -511,6 +576,7 @@ begin
         end;
         tkLeftParen: Result.Node := ParseList;
         tkLeftBracket: Result.Params := ParseParameterList;
+        tkLeftBrace: Result.Node := ParseRecordLiteral;
         tkEOF: {nop};
     else
         raise Exception.CreateFmt('Syntax Error: Unexpected token %s', [FCurrentToken.Kind.ToString]);
@@ -590,6 +656,12 @@ begin
     Result := TDataValue.Void;
 end;
 
+function TPrettyPrintVisitor.VisitKeyword(const Node: IKeywordNode): TDataValue;
+begin
+    Append(':' + Node.Value.Name);
+    Result := TDataValue.Void;
+end;
+
 function TPrettyPrintVisitor.VisitBinaryExpression(const Node: IBinaryExpressionNode): TDataValue;
 begin
     Append('(' + Node.Operator.ToString);
@@ -829,6 +901,31 @@ begin
     Result := TDataValue.Void;
 end;
 
+function TPrettyPrintVisitor.VisitRecordLiteral(const Node: IRecordLiteralNode): TDataValue;
+var
+    field: TRecordFieldLiteral;
+begin
+    if Length(Node.Fields) = 0 then
+    begin
+        Append('{}');
+        exit(TDataValue.Void);
+    end;
+
+    Append('{');
+    Indent;
+    for field in Node.Fields do
+    begin
+        NewLine;
+        Append(':' + field.Name);
+        Append(' ');
+        field.Value.Accept(Self);
+    end;
+    Unindent;
+    NewLine;
+    Append('}');
+    Result := TDataValue.Void;
+end;
+
 function TPrettyPrintVisitor.VisitCreateSeries(const Node: ICreateSeriesNode): TDataValue;
 begin
     Append(Format('(new-series "%s")', [Node.Definition]));
@@ -896,10 +993,14 @@ begin
         tkRightParen: Result := ')';
         tkLeftBracket: Result := '[';
         tkRightBracket: Result := ']';
+        tkLeftBrace: Result := '{';
+        tkRightBrace: Result := '}';
         tkQuote: Result := '''';
         tkBacktick: Result := '`';
         tkTilde: Result := '~';
+        tkAt: Result := '@';
         tkIdentifier: Result := '<identifier>';
+        tkKeyword: Result := '<keyword>';
         tkNumber: Result := '<number>';
         tkString: Result := '<string>';
         tkEOF: Result := '<EOF>';