protected override void LookupSymbolsInSingleBinder(LookupResult result, string name, int arity, ConsList <Symbol> basesBeingResolved, LookupOptions options, bool diagnose)
{
LookupResult tmp = LookupResult.GetInstance();
LookupResult nonViable = LookupResult.GetInstance();
// Member definitions of different kinds hide each other (field defs hide method defs, etc.).
// So even if the caller asks only for invocable members find any member first and then reject the result if a non-invokable is found.
LookupOptions anyMemberLookupOptions = options & ~LookupOptions.MustBeInvocableMember;
// TODO: optimize lookup (there might be many interactions in the chain)
for (ICompilation commonSubmission = Compilation.PreviousSubmission; commonSubmission != null; commonSubmission = commonSubmission.PreviousSubmission)
{
// TODO (tomat): cross-language binding - for now, skip non-C# submissions
Compilation submission = commonSubmission as Compilation;
if (submission == null)
{
continue;
}
tmp.Clear();
Imports imports = GetImports(submission);
imports.LookupSymbolInAliases(this, tmp, name, arity, basesBeingResolved, anyMemberLookupOptions, diagnose);
// If a viable using alias and a matching member are both defined in the submission an error is reported elsewhere.
// Ignore the member in such case.
if (!tmp.IsMultiViable && (options & LookupOptions.NamespaceAliasesOnly) == 0)
{
this.LookupMembers(tmp, submission.ScriptClass, name, arity, basesBeingResolved, anyMemberLookupOptions, diagnose);
}
// found a non-method in the current submission:
if (tmp.Symbols.Count > 0 && tmp.Symbols.First().Kind != SymbolKind.Method)
{
if (!tmp.IsMultiViable)
{
// skip non-viable members, but remember them in case no viable members are found in previous submissions:
nonViable.MergePrioritized(tmp);
continue;
}
if (result.Symbols.Count == 0)
{
result.MergeEqual(tmp);
}
break;
}
// merge overloads:
Debug.Assert(result.Symbols.Count == 0 || result.Symbols.All(s => s.Kind == SymbolKind.Method));
result.MergeEqual(tmp);
}
// Set a proper error if we found a symbol that is not invocable but were asked for invocable only.
// Only a single non-method can be present in the result; methods are always invocable.
if ((options & LookupOptions.MustBeInvocableMember) != 0 && result.Symbols.Count == 1)
{
Symbol symbol = result.Symbols.First();
AliasSymbol alias = symbol as AliasSymbol;
if (alias != null)
{
symbol = alias.GetAliasTarget(basesBeingResolved);
}
if (IsNonInvocableMember(symbol))
{
result.SetFrom(LookupResult.NotInvocable(symbol, result.Symbols.First(), diagnose));
}
}
else if (result.Symbols.Count == 0)
{
result.SetFrom(nonViable);
}
tmp.Free();
nonViable.Free();
}