private ExpressionSyntax ParseLogicalExpression()
{
var startToken = CurrentToken;
ExpressionSyntax left = ParseRelationalExpression();
while (true)
{
switch (CurrentToken.Type)
{
case TokenType.Or:
Next();
left = new LogicalExpressionSyntax(startToken, left, ParseRelationalExpression(),
LogicalOperator.Or);
break;
case TokenType.And:
Next();
left = new LogicalExpressionSyntax(startToken, left, ParseRelationalExpression(),
LogicalOperator.And);
break;
default:
return(left);
}
}
}
public bool EnterLogicalExpr(LogicalExpressionSyntax logicalExpr, WaddleContext ctx)
{
if (logicalExpr.Left.Accept(TypeVisitor) != TypeSymbol.Bool)
{
throw new SemanticErrorException($"Not an Bool @({logicalExpr.Left.StartToken.LineNumber}{logicalExpr.Left.StartToken.CharPosition}).");
}
if (logicalExpr.Right.Accept(TypeVisitor) != TypeSymbol.Bool)
{
throw new SemanticErrorException($"Not an Bool @({logicalExpr.Right.StartToken.LineNumber}{logicalExpr.Right.StartToken.CharPosition}).");
}
return(true);
}
private TypeSymbol WaddleExpression(ExpressionSyntax exprStmt)
{
return(exprStmt switch
{
LogicalExpressionSyntax logicalExpr => WaddleLogicalExpr(logicalExpr),
ProductExpressionSyntax productExpr => WaddleProductExpr(productExpr),
RelationalExpressionSyntax relationalExpr => WaddleRelationalExpr(relationalExpr),
TermExpressionSyntax termExpr => WaddleTermExpr(termExpr),
InvocationExpressionSyntax invocationExpr => WaddleInvocationExpr(invocationExpr),
BoolLiteralAtom _ => TypeSymbol.Bool,
IntegerLiteralAtom _ => TypeSymbol.Integer,
StringLiteralAtom _ => TypeSymbol.String,
IdentifierAtom identifierAtom => _currentFunction?.Variables[identifierAtom.Identifier].Type
?? throw new SemanticErrorException($"{identifierAtom.Identifier} does not have a type"),
_ => throw new ArgumentOutOfRangeException(nameof(exprStmt)),
});
public virtual TResult Visit(LogicalExpressionSyntax syntax)
{
return(DefaultResult);
}
public override TypeSymbol Visit(LogicalExpressionSyntax syntax)
{
return(TypeSymbol.Bool);
}
public void LeaveLogicalExpr(LogicalExpressionSyntax logicalExpr, WaddleContext ctx)
{
}
