/// <summary>
/// Searches the tree down. Returns the found symbol or null.
/// Only takes definitions into account.
/// If you would like all symbols, not only definitions, use <c>GetSymbolAtPosition</c>.
/// </summary>
public ISymbolInformation TopDown(ISymbolInformation rootEntry, Uri file, int line, int character)
{
if (rootEntry == null)
{
return(null);
}
ISymbolInformation bestMatch = null;
if (SymbolUtil.PositionIsWithinSymbolTotalRange(rootEntry, file, line, character))
{
bestMatch = rootEntry;
}
foreach (var child in rootEntry.Children)
{
if (SymbolUtil.PositionIsWithinSymbolTotalRange(child, file, line, character))
{
bestMatch = child;
if (child.HasChildren)
{
var match = TopDown(child, file, line, character);
bestMatch = match ?? bestMatch;
}
}
// in case no better match was found,
// check default scope too
if (
(bestMatch == null || bestMatch.Equals(rootEntry)) &&
(child.Name == Resources.SymbolTableStrings.default_class || child.Name == Resources.SymbolTableStrings.default_module) &&
(child.Children?.Any() ?? false)
)
{
bestMatch = TopDown(child, file, line, character);
}
}
return(bestMatch);
}
/// <summary>
/// Searches the tree downwards to match a specific location.
/// Only symbols that wrap the location are searched.
/// <returns> Returns the match oder null.</returns>
/// This will find all symbols, not only definitions.
/// If you would like to search for definitions only, use <c>TopDown</c>
/// </summary>
public ISymbolInformation GetSymbolAtPosition(ISymbolInformation rootEntry, Uri file, int line, int character)
{
if (rootEntry == null || (!SymbolUtil.PositionIsWithinSymbolTotalRange(rootEntry, file, line, character) && (rootEntry.Name != Resources.SymbolTableStrings.default_module)))
{
return(null);
}
var wrappingSymbol = TopDown(rootEntry, file, line, character);
if (wrappingSymbol?.Descendants != null)
{
foreach (var symbol in wrappingSymbol.Descendants)
{
if (SymbolUtil.PositionIsWithinSymbolIdentifier(symbol, file, line, character))
{
return(symbol);
}
}
}
if (line == wrappingSymbol?.Line && character <= wrappingSymbol.IdentifierEndColumn)
{
return(wrappingSymbol);
}
return(null);
}