public override void VisitAssignment(AssignmentStatement assignment)
{
Visit(assignment.Value);
var newCommand = new Assignment(assignment.VariableName.Name, ExpressionStack.Pop());
Program.Add(newCommand);
}
public override void VisitPrint(PrintStatement printStatement)
{
Visit(printStatement.Expression);
var print = new Print(ExpressionStack.Pop(), printStatement.NewLine);
Program.Add(print);
}
public override void VisitUnaryExpression(UnaryExpression unaryExpression)
{
Visit(unaryExpression.Operand);
var unaryOp = new UnaryOperation(unaryExpression.Operation, ExpressionStack.Pop());
var variable = new Identifier(NewVariable);
var assignment = new Assignment(variable.Name, unaryOp);
Program.Add(assignment);
ExpressionStack.Push(variable);
}
public override void VisitBinaryExpression(BinaryExpression binaryExpression)
{
Visit(binaryExpression.Left);
var leftExpression = ExpressionStack.Pop();
Visit(binaryExpression.Right);
var rightExpression = ExpressionStack.Pop();
var variable = new Identifier(NewVariable);
var binOp = new BinaryOperation(leftExpression, binaryExpression.Operation, rightExpression);
Program.Add(new Assignment(variable.Name, binOp));
ExpressionStack.Push(variable);
}
public override void VisitWhile(WhileStatement whileStatement)
{
Visit(whileStatement.Condition);
var condition = ExpressionStack.Pop();
var beginWhile = NewLabel;
var endWhile = NewLabel;
Program.Add(new ConditionalGoto(
endWhile,
new BinaryOperation(condition, Operation.Equal, 0))
{
Label = beginWhile
});
Visit(whileStatement.Body);
Program.Add(new Goto(beginWhile));
Program.Add(new NoOperation(endWhile));
}
public override void VisitFor(ForStatement forStatement)
{
Visit(forStatement.From);
Program.Add(new Assignment(forStatement.ForVariable.Name, ExpressionStack.Pop()));
var forBegin = NewLabel;
var forEnd = NewLabel;
var forVariable = new Identifier(forStatement.ForVariable.Name);
Visit(forStatement.To);
var forTo = ExpressionStack.Pop();
var check = new ConditionalGoto(
forEnd,
new BinaryOperation(forVariable, Operation.Greater, forTo))
{
Label = forBegin
};
Program.Add(check);
Visit(forStatement.Body);
Program.Add(Assignment.Increment(forVariable.Name));
Program.Add(new Goto(forBegin));
Program.Add(new NoOperation(forEnd));
}
public override void VisitIf(IfStatement ifStatement)
{
Visit(ifStatement.Condition);
var condition = ExpressionStack.Pop();
var endIfLabel = NewLabel;
var elseLabel = ifStatement.ElseBody == null ? endIfLabel : NewLabel;
Program.Add(new ConditionalGoto(
elseLabel,
new BinaryOperation(condition, Operation.Equal, 0)));
Visit(ifStatement.ThenBody);
if (ifStatement.ElseBody != null)
{
Program.Add(new Goto(endIfLabel));
Program.Add(new NoOperation(elseLabel));
Visit(ifStatement.ElseBody);
Program.Add(new NoOperation(endIfLabel));
}
else
{
Program.Add(new NoOperation(elseLabel));
}
}
public override void VisitLabelledStatement(LabelledStatement labelledStatement)
{
Program.Add(new NoOperation(labelledStatement.Label));
Visit(labelledStatement.Statement);
}
public override void VisitGotoStatement(GotoStatement gotoStatement)
{
Program.Add(new Goto(gotoStatement.Label));
}
