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Comment by Animats | Hacker News Reader

Go has most of the machinery of objects, but not the encapsulation. There are no private fields in structs.

There are, actually --- any field which begins with a lower case letter is private, any field which begins with an upper case letter is public. (Don't ask me what happens if the field begins with a letter which has a single form and does not have an explicit upper or lower case.)

Privacy is only enforced between packages, so anything in the same package as the struct can see the private fields.

> Don't ask me what happens if the field begins with a letter which has a single form and does not have an explicit upper or lower case.

So, on to the spec: https://golang.org/ref/spec#unicode_letter

> In The Unicode Standard 8.0, Section 4.5 "General Category" defines a set of character categories. Go treats all characters in any of the Letter categories Lu, Ll, Lt, Lm, or Lo as Unicode letters, and those in the Number category Nd as Unicode digits.

Which reads:

    Lu = Letter, uppercase
    Ll = Letter, lowercase
    Lt = Letter, titlecase
    Lm = Letter, modifier
    Lo = Letter, other

So I suppose (but am not sure) the case you describe falls into Lo.

Well, yes kind of.

    type foo struct {
        a int // "private"
        B int // "public"
    }

You cannot specify default values and Go refers to them as "exported" not private, but technically they are "private" in the sense that they can only be accessed via methods.

Technically, exported/unexported is different than public/private since its at the package level. You can access unexported fields of a struct from anywhere within the same package (not just from that struct's "methods"), which isn't true of a 'private' field.

IIRC, that is also true for protected members in Java (it has been a while, though, since I have written anything in Java).

If that is a concern, you can create a new package for your type.

is a field named "ß" private or public? Or ĸ?

An identifier is exported if both:

1. the first character of the identifier's name is a Unicode upper case letter (Unicode class "Lu"); and

2. the identifier is declared in the package block or it is a field name or method name.

All other identifiers are not exported.

https://golang.org/ref/spec#Exported_identifiers

Both of the characters you asked about are lowercase:

http://www.fileformat.info/info/unicode/char/00df/index.htm

http://www.fileformat.info/info/unicode/char/0138/index.htm

Here's the full list of Lu characters:

http://www.fileformat.info/info/unicode/category/Lu/list.htm

Here are the rules: https://golang.org/ref/spec#Exported_identifiers

    An identifier may be exported to permit access to it from another package.
    An identifier is exported if both:
    
        the first character of the identifier's name is a Unicode upper case letter (Unicode class "Lu"); and
        the identifier is declared in the package block or it is a field name or method name.

    All other identifiers are not exported.

Definitely one or the other, but the confusion means it's best practice to avoid fancy letters for identifiers.

Well, there's people writing code in other languages.

I know in Japan and Germany it's still kinda common for larger companies to build codebases in local languages.

Which in turn can lead to these issues.

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