private static SyntaxNode GetNegationOfConstantPattern(
SyntaxNode pattern,
SyntaxGenerator generator,
SyntaxGeneratorInternal generatorInternal
)
{
var syntaxFacts = generatorInternal.SyntaxFacts;
// If we have `is true/false` just swap that to be `is false/true`.
var expression = syntaxFacts.GetExpressionOfConstantPattern(pattern);
if (syntaxFacts.IsTrueLiteralExpression(expression))
{
return(generatorInternal.ConstantPattern(generator.FalseLiteralExpression()));
}
if (syntaxFacts.IsFalseLiteralExpression(expression))
{
return(generatorInternal.ConstantPattern(generator.TrueLiteralExpression()));
}
// Otherwise, just negate the entire pattern, we don't have anything else special we can do here.
return(generatorInternal.NotPattern(pattern));
}
private static SyntaxNode GetNegationOfUnaryPattern(
SyntaxNode pattern,
SyntaxGeneratorInternal generatorInternal,
ISyntaxFacts syntaxFacts)
{
syntaxFacts.GetPartsOfUnaryPattern(pattern, out var opToken, out var subPattern);
// not not p -> p
if (syntaxFacts.IsNotPattern(pattern))
{
return(subPattern.WithPrependedLeadingTrivia(opToken.LeadingTrivia)
.WithAdditionalAnnotations(Simplifier.Annotation));
}
// If there are other interesting unary patterns in the future, we can support specialized logic for
// negating them here.
return(generatorInternal.NotPattern(pattern));
}
public static SyntaxNode Negate(
this SyntaxGenerator generator,
SyntaxGeneratorInternal generatorInternal,
SyntaxNode expressionOrPattern,
SemanticModel semanticModel,
bool negateBinary,
CancellationToken cancellationToken)
{
var syntaxFacts = generatorInternal.SyntaxFacts;
if (syntaxFacts.IsParenthesizedExpression(expressionOrPattern))
{
return(generatorInternal.AddParentheses(
generator.Negate(
generatorInternal,
syntaxFacts.GetExpressionOfParenthesizedExpression(expressionOrPattern),
semanticModel,
negateBinary,
cancellationToken))
.WithTriviaFrom(expressionOrPattern));
}
if (negateBinary && syntaxFacts.IsBinaryExpression(expressionOrPattern))
{
return(GetNegationOfBinaryExpression(expressionOrPattern, generator, generatorInternal, semanticModel, cancellationToken));
}
if (syntaxFacts.IsLiteralExpression(expressionOrPattern))
{
return(GetNegationOfLiteralExpression(expressionOrPattern, generator, semanticModel));
}
if (syntaxFacts.IsLogicalNotExpression(expressionOrPattern))
{
return(GetNegationOfLogicalNotExpression(expressionOrPattern, syntaxFacts));
}
if (negateBinary && syntaxFacts.IsIsPatternExpression(expressionOrPattern))
{
return(GetNegationOfIsPatternExpression(expressionOrPattern, generator, generatorInternal, semanticModel, cancellationToken));
}
if (syntaxFacts.IsParenthesizedPattern(expressionOrPattern))
{
// Push the negation inside the parenthesized pattern.
return(generatorInternal.AddParentheses(
generator.Negate(
generatorInternal,
syntaxFacts.GetPatternOfParenthesizedPattern(expressionOrPattern),
semanticModel,
negateBinary,
cancellationToken))
.WithTriviaFrom(expressionOrPattern));
}
if (negateBinary && syntaxFacts.IsBinaryPattern(expressionOrPattern))
{
return(GetNegationOfBinaryPattern(expressionOrPattern, generator, generatorInternal, semanticModel, cancellationToken));
}
if (syntaxFacts.IsConstantPattern(expressionOrPattern))
{
return(GetNegationOfConstantPattern(expressionOrPattern, generator, generatorInternal));
}
if (syntaxFacts.IsUnaryPattern(expressionOrPattern))
{
return(GetNegationOfUnaryPattern(expressionOrPattern, generatorInternal, syntaxFacts));
}
// TODO(cyrusn): We could support negating relational patterns in the future. i.e.
//
// not >= 0 -> < 0
return(syntaxFacts.IsAnyPattern(expressionOrPattern)
? generatorInternal.NotPattern(expressionOrPattern)
: generator.LogicalNotExpression(expressionOrPattern));
}
private static SyntaxNode GetNegationOfBinaryExpression(
SyntaxNode expressionNode,
SyntaxGenerator generator,
SyntaxGeneratorInternal generatorInternal,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
var syntaxFacts = generatorInternal.SyntaxFacts;
syntaxFacts.GetPartsOfBinaryExpression(expressionNode, out var leftOperand, out var operatorToken, out var rightOperand);
var binaryOperation = semanticModel.GetOperation(expressionNode, cancellationToken) as IBinaryOperation;
if (binaryOperation == null)
{
// x is y -> x is not y
if (syntaxFacts.IsIsExpression(expressionNode) && syntaxFacts.SupportsNotPattern(semanticModel.SyntaxTree.Options))
{
return(generatorInternal.IsPatternExpression(leftOperand, operatorToken, generatorInternal.NotPattern(generatorInternal.TypePattern(rightOperand))));
}
// Apply the logical not operator if it is not a binary operation.
return(generator.LogicalNotExpression(expressionNode));
}
if (!s_negatedBinaryMap.TryGetValue(binaryOperation.OperatorKind, out var negatedKind))
{
return(generator.LogicalNotExpression(expressionNode));
}
else
{
var negateOperands = false;
switch (binaryOperation.OperatorKind)
{
case BinaryOperatorKind.Or:
case BinaryOperatorKind.And:
case BinaryOperatorKind.ConditionalAnd:
case BinaryOperatorKind.ConditionalOr:
negateOperands = true;
break;
}
//Workaround for https://github.com/dotnet/roslyn/issues/23956
//Issue to remove this when above is merged
if (binaryOperation.OperatorKind == BinaryOperatorKind.Or && syntaxFacts.IsLogicalOrExpression(expressionNode))
{
negatedKind = BinaryOperatorKind.ConditionalAnd;
}
else if (binaryOperation.OperatorKind == BinaryOperatorKind.And && syntaxFacts.IsLogicalAndExpression(expressionNode))
{
negatedKind = BinaryOperatorKind.ConditionalOr;
}
var newLeftOperand = leftOperand;
var newRightOperand = rightOperand;
if (negateOperands)
{
newLeftOperand = generator.Negate(generatorInternal, leftOperand, semanticModel, cancellationToken);
newRightOperand = generator.Negate(generatorInternal, rightOperand, semanticModel, cancellationToken);
}
var newBinaryExpressionSyntax = NewBinaryOperation(binaryOperation, newLeftOperand, negatedKind, newRightOperand, generator)
.WithTriviaFrom(expressionNode);
var newToken = syntaxFacts.GetOperatorTokenOfBinaryExpression(newBinaryExpressionSyntax);
var newTokenWithTrivia = newToken.WithTriviaFrom(operatorToken);
return(newBinaryExpressionSyntax.ReplaceToken(newToken, newTokenWithTrivia));
}
}
private static SyntaxNode GetNegationOfBinaryExpression(
SyntaxNode expressionNode,
SyntaxGenerator generator,
SyntaxGeneratorInternal generatorInternal,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
var syntaxFacts = generatorInternal.SyntaxFacts;
syntaxFacts.GetPartsOfBinaryExpression(expressionNode, out var leftOperand, out var operatorToken, out var rightOperand);
var operation = semanticModel.GetOperation(expressionNode, cancellationToken);
if (operation is not IBinaryOperation binaryOperation)
{
if (syntaxFacts.IsIsTypeExpression(expressionNode))
{
// `is object` -> `is null`
if (syntaxFacts.IsPredefinedType(rightOperand, PredefinedType.Object) &&
generatorInternal.SupportsPatterns(semanticModel.SyntaxTree.Options))
{
return(generatorInternal.IsPatternExpression(leftOperand, operatorToken, generatorInternal.ConstantPattern(generator.NullLiteralExpression())));
}
// `is y` -> `is not y`
if (syntaxFacts.SupportsNotPattern(semanticModel.SyntaxTree.Options))
{
return(generatorInternal.IsPatternExpression(leftOperand, operatorToken, generatorInternal.NotPattern(generatorInternal.TypePattern(rightOperand))));
}
}
// Apply the logical not operator if it is not a binary operation.
return(generator.LogicalNotExpression(expressionNode));
}
if (!s_negatedBinaryMap.TryGetValue(binaryOperation.OperatorKind, out var negatedKind))
{
return(generator.LogicalNotExpression(expressionNode));
}
if (binaryOperation.OperatorKind is BinaryOperatorKind.Or or
BinaryOperatorKind.And or
BinaryOperatorKind.ConditionalAnd or
BinaryOperatorKind.ConditionalOr)
{
leftOperand = generator.Negate(generatorInternal, leftOperand, semanticModel, cancellationToken);
rightOperand = generator.Negate(generatorInternal, rightOperand, semanticModel, cancellationToken);
}
var newBinaryExpressionSyntax = negatedKind is BinaryOperatorKind.Equals or BinaryOperatorKind.NotEquals
? generatorInternal.NegateEquality(generator, expressionNode, leftOperand, negatedKind, rightOperand)
: NegateRelational(generator, binaryOperation, leftOperand, negatedKind, rightOperand);
newBinaryExpressionSyntax = newBinaryExpressionSyntax.WithTriviaFrom(expressionNode);
var newToken = syntaxFacts.GetOperatorTokenOfBinaryExpression(newBinaryExpressionSyntax);
return(newBinaryExpressionSyntax.ReplaceToken(
newToken,
newToken.WithTriviaFrom(operatorToken)));
}