panic: reflect.Value.Interface: cannot return value obtained from unexported field or method

[jazzy-crane]

I get a panic running the following script:

package main

import (
    "fmt"

    "github.com/starlight-go/starlight"
)

type foo struct {
    HelloWorld string
}

type bar struct {
    Exported   *foo
    unexported *foo
}

func main() {
    testdata := &bar{
        Exported:   &foo{"Hello World!"},
        unexported: &foo{"hELLO wORLD!"},
    }

    globals := map[string]interface{}{
        "Println":  fmt.Println,
        "testdata": testdata,
    }

    _, err := starlight.Eval([]byte(`
Println(testdata.Exported.HelloWorld)
Println(testdata.unexported.HelloWorld)
Println(testdata.Exported)
Println(testdata.unexported)
`), globals, nil)
    if err != nil {
        fmt.Println("Error executing script;", err)
    }
}

It is the final line in the script that causes the panic (Println(testdata.unexported))

C:\MyGo\src\TEST\starlighttest>go build && starlighttest.exe
Hello World!
hELLO wORLD!
&{Hello World!}
panic: reflect.Value.Interface: cannot return value obtained from unexported field or method

goroutine 1 [running]:
reflect.valueInterface(0x577960, 0xc00004e218, 0x1b6, 0x1, 0x10, 0x58b580)
        C:/Go/src/reflect/value.go:959 +0x1c5
reflect.Value.Interface(0x577960, 0xc00004e218, 0x1b6, 0x0, 0x703dc0)
        C:/Go/src/reflect/value.go:948 +0x4b
github.com/starlight-go/starlight/convert.FromValue(0x5e6340, 0xc0000547c0, 0x1, 0xc00004e430)
        C:/MyGo/src/github.com/starlight-go/starlight/convert/conv.go:109 +0x1cb
github.com/starlight-go/starlight/convert.FromTuple(0xc00004e420, 0x1, 0x1, 0x5e7060, 0x58a200, 0x8)
        C:/MyGo/src/github.com/starlight-go/starlight/convert/conv.go:152 +0xaf
github.com/starlight-go/starlight/convert.makeVariadicStarFn.func1(0xc00006e9f0, 0xc00006e9c0, 0xc00004e420, 0x1, 0x1, 0x0, 0x0, 0x0, 0x50, 0x5a4020, ...)
        C:/MyGo/src/github.com/starlight-go/starlight/convert/conv.go:340 +0xcb
go.starlark.net/starlark.(*Builtin).CallInternal(0xc00006e9c0, 0xc00006e9f0, 0xc00004e420, 0x1, 0x1, 0x0, 0x0, 0x0, 0x703dc0, 0x411053, ...)
        C:/MyGo/src/go.starlark.net/starlark/value.go:632 +0x92
go.starlark.net/starlark.Call(0xc00006e9f0, 0x5e6380, 0xc00006e9c0, 0xc00004e420, 0x1, 0x1, 0x0, 0x0, 0x0, 0x5e6540, ...)
        C:/MyGo/src/go.starlark.net/starlark/eval.go:991 +0x14e
go.starlark.net/starlark.(*Function).CallInternal(0xc0000ae000, 0xc00006e9f0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x8, 0x0, ...)
        C:/MyGo/src/go.starlark.net/starlark/interp.go:283 +0x3da3
go.starlark.net/starlark.Call(0xc00006e9f0, 0x5e6400, 0xc0000ae000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc000082020, ...)
        C:/MyGo/src/go.starlark.net/starlark/eval.go:991 +0x14e
go.starlark.net/starlark.(*Program).Init(0xc000082020, 0xc00006e9f0, 0xc00006e990, 0xc000054460, 0xc00004e240, 0xc0000a4060)
        C:/MyGo/src/go.starlark.net/starlark/eval.go:339 +0xa1
go.starlark.net/starlark.ExecFile(0xc00006e9f0, 0x5b92d1, 0x8, 0x57ce00, 0xc000054460, 0xc00006e990, 0x20, 0x57ce00, 0x1)
        C:/MyGo/src/go.starlark.net/starlark/eval.go:268 +0xf4
github.com/starlight-go/starlight.Eval(0x57ce00, 0xc000054460, 0xc00007fe48, 0x0, 0x87, 0x90, 0xd0)
        C:/MyGo/src/github.com/starlight-go/starlight/starlight.go:41 +0x161
main.main()
        C:/MyGo/src/TEST/starlighttest/starlighttest.go:29 +0x251

[ORESoftware]

+1