recursive maps (use case: to emulate packages)

[glycerine]

Wondering how I could create a working math.Pow(2,3) and math.Log(2).

I tried:

    lib := make(map[string]interface{})
    lib["Pow"] = math.Pow
    sdict, err := convert.MakeStringDict(lib) // also doesn't work if we omit this
    panicOn(err)
    env.Starlark.GoGlobal["math"] = sdict
    dict, err = convert.MakeStringDict(env.Starlark.GoGlobal)
    panicOn(err)
    // use dict as the globals in a call

but I get

Error: starlight_map<map[string]interface {}> has no .Pow field or method

or

Error: starlight_map<starlark.StringDict> has no .Pow field or method

ah. conv.go:48 has a TODO that indicates recursive maps aren't implemented.

update: also I've been doing too much Lua where this actually works and maps (tables) can act as packages (which makes sense since they are both just hash tables). Python doesn't like this syntax

Python 3.7.1 (default, Nov  6 2018, 18:45:35)
[Clang 10.0.0 (clang-1000.11.45.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> a={"b":2}
>>> a
{'b': 2}
>>> a.b
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'dict' object has no attribute 'b'
>>>

so some other way to represent packages is needed if python "use this package after import" is to be realized.

[glycerine]

added the necessary functionality in https://github.com/glycerine/starlark-go/tree/attr and proffered it in google/starlark-go#79

#11 fixes this, once the pull request is merged.