public static ITypeSymbol GetMatchedTypeSymbol(
this PatternSyntax pattern,
SyntaxNodeAnalysisContext context,
ITypeSymbol type,
HashSet <ITypeSymbol> allCases,
bool isClosed)
{
ITypeSymbol symbolUsed;
switch (pattern)
{
case DeclarationPatternSyntax declarationPattern:
symbolUsed = context.GetDeclarationType(declarationPattern);
break;
case DiscardPatternSyntax _:
case ConstantPatternSyntax constantPattern
when constantPattern.IsNull():
// Ignored
return(null);
case VarPatternSyntax _:
case RecursivePatternSyntax _:
default:
context.ReportCasePatternNotSupported(pattern);
return(null);
}
if (isClosed && !allCases.Contains(symbolUsed))
{
var diagnostic = Diagnostic.Create(ExhaustiveMatchAnalyzer.MatchMustBeOnCaseType,
pattern.GetLocation(), symbolUsed.GetFullName(), type.GetFullName());
context.ReportDiagnostic(diagnostic);
}
return(symbolUsed);
}
