My vote is for "in the package that needs them"
On Tuesday, 22 November 2016 02:30:21 UTC+11, Vorn Mom wrote:
>
> Sorry if it was asked before, but where should interfaces live?
>
> - In the package that contains an implementation of it.
> - In its own package.
> - or in the package that needs it.
>
> The standard library is not consistent. For example:
>
> - io.Writer is defined in a package that also has an implementation,
> io.PipeWriter.
> - Encoding is all interfaces, defering implementation to sub-packages.
> - database/sql returns a DB struct on Open() instead of an interface.
>
> Because Go interfaces are decoupled from implementation, I think it should
> be defined where it's needed. So I like having my own interface for DB
> that may only define a subset of what behaviors it provides.
>
> However, doesn't defining an interface that depends on other packages
> decrease cohesion and leaks the abstraction? For example,
>
> type interface DbQuery {
> QueryRow(query string, args ...interface{}) *sql.Row
> }
>
> This interface depends on sql.Row. This decreases cohesion because the
> interface is now defined across packages?
>
> -Vorn
>
>
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
