private SyntaxTree ParseTerm(int precedenceLevel)
{
Token token = CurrentToken;
SyntaxTree tree = null;
Operator op;
if (TryResolveOperator(token.TokenType, true, out op) && GetOperatorAryness(op) == Aryness.Unary)
{
Match(CurrentToken.TokenType);
UnaryOperatorTree unaryOperator = new UnaryOperatorTree(token);
unaryOperator.Operator = op;
unaryOperator.Operand = ParseExpression(GetPrecedenceLevel(op));
tree = unaryOperator;
}
else if (token.TokenType == TokenType.OpenParenthesis)
{
Match(TokenType.OpenParenthesis);
tree = ParseMathExpression(0);
Match(TokenType.CloseParenthesis);
}
else
{
tree = ParseFactorOrFunctionCall();
}
return(tree);
}
protected virtual string EmitUnaryOperator(UnaryOperatorTree op)
{
string code = string.Empty;
switch (op.Operator)
{
case Operator.UnaryNot:
code = string.Format(
"!{0}",
EmitExpression(op.Operand)
);
break;
case Operator.UnaryMinus:
code = string.Format(
"-({0})",
EmitExpression(op.Operand)
);
break;
case Operator.UnaryPlus:
code = string.Format(
"+({0})",
EmitExpression(op.Operand)
);
break;
default:
throw new InternalCompilerException(
string.Format("Could not generate code for unary operator: {0}", op.Operator)
);
}
return(code);
}
protected virtual List <CodeErrorException> TypeCheckUnaryOperator(UnaryOperatorTree op)
{
List <CodeErrorException> errors = new List <CodeErrorException>();
switch (op.Operator)
{
case Operator.UnaryMinus:
case Operator.UnaryPlus:
break;
default:
errors.Add(
new CodeErrorException(
op.Token.Line,
op.Token.StartPosition,
op.Token.EndPosition,
string.Format(
"Typechecker does not support unary operator '{0}'",
op.Token.Value
)
)
);
break;
}
// typecheck expressions
errors.AddRange(TypeCheckExpression(op.Operand));
return(errors);
}