expr-scan.cs

EnumerableEx.Generate(
    EnumerableEx.Return((Expression) expr),
    _ => _.Any(),
    _ => _.SelectMany(e =>
        EnumerableEx.Generate(e.GetType(), t => t.BaseType != null, t => t.BaseType, t => t)
            .SelectMany(t => t.GetFields(BindingFlags.NonPublic | BindingFlags.Instance))
            .Where(t => t.FieldType.IsAssignableFrom(typeof(Expression)))
            .Select(f => (Expression) f.GetValue(e))
    ),
    _ => _
).SelectMany(_ => _);