private static ExpressionBodyTuple MakeExpressionBody(ref TokenReader reader)
{
bool rewind = TryLookAhead(ref reader, Token.TokenType.Exclamation);
if (TryLookAhead(ref reader, Token.TokenType.OpenBracket, false))
{
// 開き括弧/!マーク -> クラスタ
if (rewind)
reader.RewindOne();
return new ExpressionBodyTuple() { Cluster = MakeCluster(ref reader) };
}
else
{
if (rewind)
reader.RewindOne();
return new ExpressionBodyTuple() { MethodDeclaration = MakeMethodDeclaration(ref reader) };
}
}