public override void Visit(DeclarationStmt declarationStmt)
{
IdentifierExpr id = declarationStmt.Identifier;
if (declarationStmt.AssignmentExpr != null)
{
declarationStmt.AssignmentExpr.Accept(this);
SymbolTable.GetSymbol(id.IdentifierName).Value = declarationStmt.AssignmentExpr.ExprValue;
}
}
public override void Visit(DeclarationStmt declarationStmt)
{
IdentifierExpr id = declarationStmt.Identifier;
if (!SymbolTable.AddSymbol(id.IdentifierName, declarationStmt.Type.Type))
{
Errors.AddError(String.Format("Already declared variable {0} at line {1} column {2}.",
id.IdentifierName, id.Line, id.Column), ErrorTypes.SemanticError);
}
if (declarationStmt.AssignmentExpr != null)
{
Expression assignment = declarationStmt.AssignmentExpr;
assignment.Accept(this);
if (assignment.Type == ExprType.VoidType)
return;
if (assignment.Type != declarationStmt.Type.Type)
{
Errors.AddError(String.Format("Can't assign expression of type {0} in variable {1} of type {2} at line {3} column {4}.",
assignment.Type, id.IdentifierName, declarationStmt.Type, declarationStmt.Line, declarationStmt.Column), ErrorTypes.SemanticError);
}
}
declarationStmt.Identifier.Type = declarationStmt.Type.Type;
}
private Statement ParseStatement()
{
if (Accept(Token.Types.KwVar))
{
DeclarationStmt declaration = new DeclarationStmt(AcceptedToken.Line, AcceptedToken.Column);
Token id = Match(Token.Types.Identifier);
declaration.Identifier = new IdentifierExpr(id.Line, id.Column, id.Content);
Match(Token.Types.Colon);
TypeNode typeNode = ParseType();
declaration.Type = typeNode;
if (Accept(Token.Types.OpAssignment))
{
declaration.AssignmentExpr = ParseExpression();
}
return declaration;
}
else if (Accept(Token.Types.Identifier))
{
AssignmentStmt statement = new AssignmentStmt(AcceptedToken.Line, AcceptedToken.Column);
statement.Identifier = new IdentifierExpr(AcceptedToken.Line, AcceptedToken.Column, AcceptedToken.Content);
Match(Token.Types.OpAssignment);
statement.AssignmentExpr = ParseExpression();
return statement;
}
else if (Accept(Token.Types.KwFor))
{
ForStmt statement = new ForStmt(AcceptedToken.Line, AcceptedToken.Column);
Token idToken = Match(Token.Types.Identifier);
statement.LoopVar = new IdentifierExpr(idToken.Line, idToken.Column, idToken.Content);
Match(Token.Types.KwIn);
statement.StartExpr = ParseExpression();
Match(Token.Types.OpRange);
statement.EndExpr = ParseExpression();
Match(Token.Types.KwDo);
statement.Body = ParseStatements(new StmtList(CurrentToken.Line, CurrentToken.Column));
Match(Token.Types.KwEnd);
Match(Token.Types.KwFor);
return statement;
}
else if (Accept(Token.Types.KwRead))
{
ReadStmt statement = new ReadStmt(AcceptedToken.Line, AcceptedToken.Column);
Token idToken = Match(Token.Types.Identifier);
statement.Variable = new IdentifierExpr(idToken.Line, idToken.Column, idToken.Content);
return statement;
}
else if (Accept(Token.Types.KwPrint))
{
PrintStmt statement = new PrintStmt(AcceptedToken.Line, AcceptedToken.Column);
statement.PrintExpr = ParseExpression();
return statement;
}
else if (Accept(Token.Types.KwAssert))
{
AssertStmt statement = new AssertStmt(AcceptedToken.Line, AcceptedToken.Column);
Match(Token.Types.LParen);
statement.AssertExpr = ParseExpression();
Match(Token.Types.RParen);
return statement;
}
throw new ParserException(String.Format("Expected statement, got {0} instead at line {1} column {2}.",
CurrentToken.Type, CurrentToken.Line, CurrentToken.Column));
}
public void Visit(DeclarationStmt declarationStmt)
{
TreeLevel++;
PrintNode("Declaration");
PrintNode("Name " + declarationStmt.Identifier.IdentifierName, true);
declarationStmt.Type.Accept(this);
if (declarationStmt.AssignmentExpr != null)
declarationStmt.AssignmentExpr.Accept(this);
TreeLevel--;
}
