public AnnotatedForStatement(VariableSymbol variable, AnnotatedExpression lowerBound, AnnotatedExpression upperBound, AnnotatedStatement body)
{
Variable = variable;
LowerBound = lowerBound;
UpperBound = upperBound;
Body = body;
}
private object EvaluateExpression(AnnotatedExpression root)
{
if (root is AnnotatedTypeCastExpression t)
{
var left = EvaluateExpression(t.Left);
return(PerformTypeCast(left, t.Right));
}
if (root is AnnotatedLiteralExpression n)
{
return(n.Value);
}
if (root is AnnotatedVariableExpression v)
{
return(_symbolTable[v.Symbol]);
}
if (root is AnnotatedAssignmentExpression a)
{
var value = EvaluateExpression(a.Expression);
_symbolTable[a.Symbol] = value;
return(value);
}
if (root is AnnotatedUnaryExpression u)
{
object operand = EvaluateExpression(u.Operand);
switch (u.Operator.Kind)
{
case AnnotatedUnaryOperatorKind.Identity: return((int)operand);
case AnnotatedUnaryOperatorKind.Negation: return(-(int)operand);
case AnnotatedUnaryOperatorKind.LogicalNegation: return(!(bool)operand);
default: throw new Exception($"Unexpected Unary expression {u.Operator.Kind}");
}
}
if (root is AnnotatedBinaryExpression b)
{
object left = EvaluateExpression(b.Left);
object right = EvaluateExpression(b.Right);
switch (b.Operator.Kind)
{
case AnnotatedBinaryOperatorKind.Addition: return((int)left + (int)right);
case AnnotatedBinaryOperatorKind.Subtraction: return((int)left - (int)right);
case AnnotatedBinaryOperatorKind.Multiplication: return((int)left * (int)right);
case AnnotatedBinaryOperatorKind.Division: {
if ((int)right == 0)
{
throw new Exception("ERROR: Division by Zero");
}
return((int)left / (int)right);
}
case AnnotatedBinaryOperatorKind.LogicalAnd: return((bool)left && (bool)right);
case AnnotatedBinaryOperatorKind.LogicalOr: return((bool)left || (bool)right);
case AnnotatedBinaryOperatorKind.Xor: return((int)left ^ (int)right);
case AnnotatedBinaryOperatorKind.And: return((int)left & (int)right);
case AnnotatedBinaryOperatorKind.Or: return((int)left | (int)right);
case AnnotatedBinaryOperatorKind.Equality: return(Equals(left, right));
case AnnotatedBinaryOperatorKind.Inequality:
return(!Equals(left, right));
case AnnotatedBinaryOperatorKind.GreaterThan: return((int)left > (int)right);
case AnnotatedBinaryOperatorKind.GreaterThanEqual: return((int)left >= (int)right);
case AnnotatedBinaryOperatorKind.LessThan: return((int)left < (int)right);
case AnnotatedBinaryOperatorKind.LessThanEqual: return((int)left <= (int)right);
default: throw new Exception($"Unexpected binary operator {b.Operator.Kind}");
}
}
throw new Exception($"Unexpected node {root.Kind}");
}
public AnnotatedWhileStatement(AnnotatedExpression condition, AnnotatedStatement body)
{
Condition = condition;
Body = body;
}
public AnnotateVariableDeclaration(VariableSymbol variable, AnnotatedExpression initializer)
{
Variable = variable;
Initializer = initializer;
}
public AnnotatedIfStatement(AnnotatedExpression condition, AnnotatedStatement thenStatement, AnnotatedStatement elseStatement)
{
Condition = condition;
ThenStatement = thenStatement;
ElseStatement = elseStatement;
}