How can I read private field in go struct instance

[杜沁园]

I recently write a program to recursively print all fields and value in a struct. Interface() is the most convinence way to get underlying value in go.

But it will panic when field is private.How can I access private field? 

For simple type, I can stil use Int(),Bool(),etc to read private field.   But if the field is a interface, I do not know how to access is concrete value without use Interface() method.

For example:

type Expr interface {
   eval(v string) bool
}

type MyExpr struct {
   Haha string
}

type Web struct {
   Host    string
   epr     Expr
}

How can I get Web.Epr Value by reflection without use Interface() method

[Weiming Shi]

Let us have some concrete code snippet for discussion:

https://play.golang.org/p/fdcEs3k9U8I

Is this what you would like to have?

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[Dan Kortschak]

Sorry, missed the go- prefix in Dave's package.

github.com/davecgh/go-spew

On Tue, 2019-06-04 at 09:48 +0930, Dan Kortschak wrote:
> There are packages already available for this.
>
> github.com/kortschak/utter (for Go syntax-like printing)
> github.com/davecgh/spew (for less Go syntax-like printing)

[Dan Kortschak]

There are packages already available for this.

github.com/kortschak/utter (for Go syntax-like printing)
github.com/davecgh/spew (for less Go syntax-like printing)



On Mon, 2019-06-03 at 08:54 -0700, 杜沁园 wrote:

[杜沁园]

go-spew is a really good library, I don not need to write it myself, Thanks

在 2019年6月4日星期二 UTC+8上午8:19:55，kortschak写道：

[Dan Kortschak]

The code in utter is essentially the same (I forked it from go-spew),
but the output can be used in Go code. Depending on what you want, both
are useful.