protected override bool TryAnalyzeVariableDeclaration(TypeSyntax typeName, SemanticModel semanticModel, OptionSet optionSet, CancellationToken cancellationToken, out TextSpan issueSpan)
{
issueSpan = default(TextSpan);
// If it is currently not var, explicit typing exists, return.
// this also takes care of cases where var is mapped to a named type via an alias or a class declaration.
if (!typeName.IsTypeInferred(semanticModel))
{
return(false);
}
if (typeName.Parent.IsKind(SyntaxKind.VariableDeclaration) &&
typeName.Parent.Parent.IsKind(SyntaxKind.LocalDeclarationStatement, SyntaxKind.ForStatement, SyntaxKind.UsingStatement))
{
// check assignment for variable declarations.
var variable = ((VariableDeclarationSyntax)typeName.Parent).Variables.First();
if (!AssignmentSupportsStylePreference(variable.Identifier, typeName, variable.Initializer, semanticModel, optionSet, cancellationToken))
{
return(false);
}
}
issueSpan = typeName.Span;
return(true);
}
private bool IsInferredPredefinedType(SyntaxNode declarationStatement, SemanticModel semanticModel, CancellationToken cancellationToken)
{
TypeSyntax typeSyntax = GetTypeSyntaxFromDeclaration(declarationStatement);
return(typeSyntax != null
? typeSyntax.IsTypeInferred(semanticModel) &&
semanticModel.GetTypeInfo(typeSyntax).Type?.IsSpecialType() == true
: false);
}
protected override bool TryAnalyzeVariableDeclaration(TypeSyntax typeName, SemanticModel semanticModel, OptionSet optionSet, CancellationToken cancellationToken, out TextSpan issueSpan)
{
// If it is already var, return.
if (typeName.IsTypeInferred(semanticModel))
{
issueSpan = default(TextSpan);
return(false);
}
var candidateReplacementNode = SyntaxFactory.IdentifierName("var");
var candidateIssueSpan = typeName.Span;
// If there exists a type named var, return.
var conflict = semanticModel.GetSpeculativeSymbolInfo(typeName.SpanStart, candidateReplacementNode, SpeculativeBindingOption.BindAsTypeOrNamespace).Symbol;
if (conflict?.IsKind(SymbolKind.NamedType) == true)
{
issueSpan = default(TextSpan);
return(false);
}
if (typeName.Parent.IsKind(SyntaxKind.VariableDeclaration) &&
typeName.Parent.IsParentKind(SyntaxKind.LocalDeclarationStatement, SyntaxKind.ForStatement, SyntaxKind.UsingStatement))
{
var variableDeclaration = (VariableDeclarationSyntax)typeName.Parent;
// implicitly typed variables cannot be constants.
if ((variableDeclaration.Parent as LocalDeclarationStatementSyntax)?.IsConst == true)
{
issueSpan = default(TextSpan);
return(false);
}
var variable = variableDeclaration.Variables.Single();
if (AssignmentSupportsStylePreference(
variable.Identifier, typeName, variable.Initializer.Value,
semanticModel, optionSet, cancellationToken))
{
issueSpan = candidateIssueSpan;
return(true);
}
}
else if (typeName.Parent is ForEachStatementSyntax foreachStatment)
{
var foreachStatementInfo = semanticModel.GetForEachStatementInfo(foreachStatment);
if (foreachStatementInfo.ElementConversion.IsIdentityOrImplicitReference())
{
issueSpan = candidateIssueSpan;
return(true);
}
}
issueSpan = default(TextSpan);
return(false);
}
internal override bool TryAnalyzeVariableDeclaration(
TypeSyntax typeName, SemanticModel semanticModel,
OptionSet optionSet, CancellationToken cancellationToken)
{
// var (x, y) = e;
// foreach (var (x, y) in e) ...
if (typeName.IsParentKind(SyntaxKind.DeclarationExpression))
{
var parent = (DeclarationExpressionSyntax)typeName.Parent;
if (parent.Designation.IsKind(SyntaxKind.ParenthesizedVariableDesignation))
{
return(true);
}
}
// If it is currently not var, explicit typing exists, return.
// this also takes care of cases where var is mapped to a named type via an alias or a class declaration.
if (!typeName.IsTypeInferred(semanticModel))
{
return(false);
}
if (typeName.Parent.IsKind(SyntaxKind.VariableDeclaration) &&
typeName.Parent.Parent.IsKind(SyntaxKind.LocalDeclarationStatement, SyntaxKind.ForStatement, SyntaxKind.UsingStatement))
{
// check assignment for variable declarations.
var variable = ((VariableDeclarationSyntax)typeName.Parent).Variables.First();
if (!AssignmentSupportsStylePreference(
variable.Identifier, typeName, variable.Initializer.Value,
semanticModel, optionSet, cancellationToken))
{
return(false);
}
}
else if (typeName.Parent.IsKind(SyntaxKind.ForEachStatement))
{
var foreachStatement = (ForEachStatementSyntax)typeName.Parent;
if (!AssignmentSupportsStylePreference(
foreachStatement.Identifier, typeName, foreachStatement.Expression,
semanticModel, optionSet, cancellationToken))
{
return(false);
}
}
return(true);
}