在GO中以小写字母开头时如何将错误接口暴露在外面？

Question

In the GO language specification its said things which needs to be exported outside package must starts with capital letter. I am wondering how error interface is exposed outside and can be accessible anywhere even though it starts with small letter unlike other interfaces starts with capital letter like Stringer.

Answer 1

error is a builtin type just like int, bool, string etc. I guess you've never wondered why int is available despite starting with a lowecased letter.

Builtin types are predeclared identifiers, they are implicitly declared in the universe block and so available everywhere without any imports or qualifiers.