/// <summary>
/// Gets the descendants of the specified element that match the specified type and predicate.
/// </summary>
private static List <TElement> GetDescendants <TElement>(SyntaxElement element, Func <TElement, bool> predicate, List <TElement> list)
where TElement : SyntaxElement
{
for (int i = 0; i < element.ChildCount; i++)
{
var child = element.GetChild(i);
if (child != null)
{
if (child is TElement ce && (predicate == null || predicate(ce)))
{
if (list == null)
{
list = new List <TElement>();
}
list.Add(ce);
}
if (child is SyntaxNode cn)
{
list = GetDescendants(child, predicate, list);
}
}
}
return(list);
}
/// <summary>
/// Gets the descendants of the specified element that match the specified type and predicate.
/// </summary>
private static IReadOnlyList <TElement> GetDescendants <TElement>(
SyntaxElement element,
Func <TElement, bool> predicate,
bool includeSelf)
where TElement : SyntaxElement
{
List <TElement> list = null;
if (includeSelf && element is TElement telem && (predicate == null || predicate(telem)))
{
list = list ?? new List <TElement>();
list.Add(telem);
}
var root = element;
var childIndex = 0;
while (element != null)
{
if (childIndex < element.ChildCount && childIndex >= 0)
{
// walk down
var child = element.GetChild(childIndex);
if (child != null)
{
element = child;
childIndex = 0;
if (element is TElement telem2 && (predicate == null || predicate(telem2)))
{
list = list ?? new List <TElement>();
list.Add(telem2);
}
}
else
{
childIndex++;
}
}
else if (element == root)
{
break;
}
else
{
// walk up
childIndex = element.IndexInParent + 1;
element = element.Parent;
}
}
return(list != null?list.ToReadOnly() : EmptyReadOnlyList <TElement> .Instance);
}
protected static void GatherDiagnostics(
SyntaxElement element,
List <Diagnostic> diagnostics,
DiagnosticsInclude include,
CancellationToken cancellationToken = default(CancellationToken))
{
cancellationToken.ThrowIfCancellationRequested();
bool includeSyntax = (include & DiagnosticsInclude.Syntactic) != 0;
bool includeSemantic = (include & DiagnosticsInclude.Semantic) != 0;
bool includeExpansion = (include & DiagnosticsInclude.Expansion) != 0;
if (element.HasSyntaxDiagnostics && includeSyntax)
{
// each syntax diagnostic is located at the element that carries it.
diagnostics.AddRange(element.SyntaxDiagnostics.Select(d => d.HasLocation ? d : SetLocation(d, element)));
}
if (includeSemantic && element is SyntaxNode node && node.SemanticDiagnostics.Count > 0)
{
diagnostics.AddRange(node.SemanticDiagnostics);
}
if (includeSemantic || (includeSyntax && element.ContainsSyntaxDiagnostics))
{
for (int i = 0, n = element.ChildCount; i < n; i++)
{
var child = element.GetChild(i);
if (child != null)
{
GatherDiagnostics(child, diagnostics, include, cancellationToken);
}
}
}
if (includeExpansion && element is Expression expr && expr.GetExpansion() is SyntaxNode expansion)
{
var originalCount = diagnostics.Count;
GatherDiagnostics(expansion, diagnostics, include, cancellationToken);
if (diagnostics.Count > originalCount)
{
var name = expr.ReferencedSymbol?.Name ?? "<unknown>";
var location = expr is FunctionCallExpression fc ? fc.Name : expr;
var errors = diagnostics[originalCount].Message;
var dx = DiagnosticFacts.GetErrorInExpansion(name, errors).WithLocation(location);
diagnostics.SetCount(originalCount);
diagnostics.Add(dx);
}
}
}
private static TElement GetFirstDescendant <TElement>(SyntaxElement element, Func <TElement, bool> predicate, bool includeSelf)
where TElement : SyntaxElement
{
if (includeSelf && element is TElement telem && (predicate == null || predicate(telem)))
{
return(telem);
}
var root = element;
var childIndex = 0;
while (element != null)
{
if (childIndex < element.ChildCount && childIndex >= 0)
{
// walk down
var child = element.GetChild(childIndex);
if (child != null)
{
element = child;
childIndex = 0;
if (element is TElement telem2 && (predicate == null || predicate(telem2)))
{
return(telem2);
}
}
else
{
childIndex++;
}
}
else if (element == root)
{
break;
}
else
{
// walk up
childIndex = element.IndexInParent + 1;
element = element.Parent;
}
}
return(null);
}