public static bool IsExplicitThatCanBeImplicit(
VariableDeclarationSyntax variableDeclaration,
SemanticModel semanticModel,
TypeAppearance typeAppearance,
CancellationToken cancellationToken = default(CancellationToken))
{
TypeSyntax type = variableDeclaration.Type;
Debug.Assert(type != null);
if (type == null)
{
return(false);
}
if (type.IsVar)
{
return(false);
}
switch (variableDeclaration.Parent.Kind())
{
case SyntaxKind.FieldDeclaration:
case SyntaxKind.EventFieldDeclaration:
{
return(false);
}
case SyntaxKind.LocalDeclarationStatement:
{
if (((LocalDeclarationStatementSyntax)variableDeclaration.Parent).IsConst)
{
return(false);
}
break;
}
}
Debug.Assert(variableDeclaration.Variables.Any());
ExpressionSyntax expression = variableDeclaration
.Variables
.SingleOrDefault(shouldThrow: false)?
.Initializer?
.Value?
.WalkDownParentheses();
if (expression == null)
{
return(false);
}
if (expression.IsKind(SyntaxKind.NullLiteralExpression, SyntaxKind.DefaultLiteralExpression))
{
return(false);
}
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(type, cancellationToken);
if (typeSymbol == null)
{
return(false);
}
if (typeSymbol.IsKind(SymbolKind.ErrorType, SymbolKind.DynamicType))
{
return(false);
}
if (!typeSymbol.Equals(semanticModel.GetTypeSymbol(expression, cancellationToken)))
{
return(false);
}
switch (typeAppearance)
{
case TypeAppearance.Obvious:
return(IsObvious(expression, semanticModel, cancellationToken));
case TypeAppearance.NotObvious:
return(!IsObvious(expression, semanticModel, cancellationToken));
}
Debug.Assert(typeAppearance == TypeAppearance.None, typeAppearance.ToString());
return(true);
}
public static bool IsImplicitThatCanBeExplicit(
VariableDeclarationSyntax variableDeclaration,
SemanticModel semanticModel,
TypeAppearance typeAppearance,
CancellationToken cancellationToken = default(CancellationToken))
{
TypeSyntax type = variableDeclaration.Type;
Debug.Assert(type != null);
if (type == null)
{
return(false);
}
if (!type.IsVar)
{
return(false);
}
if (variableDeclaration.IsParentKind(SyntaxKind.FieldDeclaration, SyntaxKind.EventFieldDeclaration))
{
return(false);
}
Debug.Assert(variableDeclaration.Variables.Any());
ExpressionSyntax expression = variableDeclaration
.Variables
.FirstOrDefault()?
.Initializer?
.Value?
.WalkDownParentheses();
if (expression == null)
{
return(false);
}
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(type, cancellationToken);
if (typeSymbol == null)
{
return(false);
}
if (typeSymbol.IsKind(SymbolKind.ErrorType, SymbolKind.DynamicType))
{
return(false);
}
if (!typeSymbol.SupportsExplicitDeclaration())
{
return(false);
}
switch (typeAppearance)
{
case TypeAppearance.Obvious:
return(IsObvious(expression, semanticModel, cancellationToken));
case TypeAppearance.NotObvious:
return(!IsObvious(expression, semanticModel, cancellationToken));
}
Debug.Assert(typeAppearance == TypeAppearance.None, typeAppearance.ToString());
return(true);
}
