where

go-where -- Find where a Go identifier is defined

Library and a command-line utility to locate Go definitions.

$ go-where github.com/tv42/where#Ident
/home/tv/go/src/github.com/tv42/where/where.go:30:6

So far, the Go community has not standardized on a way to type a full import and identifiers into a single string. Using dot . as a separator between the import path and identifiers (as opposed to package names and identifiers) is ambiguous; example.com/foo.bar.baz, we can't tell where the repository part ends.

To avoid ambiguity, we choose a separator character that is not found in import paths: the hash sign, #. In practice, you can think of the input as "what godoc.org would take".

The input syntax is IMPORTPATH[#IDENTIFIER[.FIELD]...[.METHOD]], or simplifying IMPORTPATH[#NAME[.NAME]...].

go-where is primarily intended for uses like embedding stable links to source into other files -- see below for Emacs org-mode integration.

As such, more value is placed on clarity over conciseness, and we do not accept ambiguous input; go doc exec.Cmd.Run may happen to find the right thing for simple cases, but go-where os/exec#Cmd.Run will never pick the wrong definition.

go-where differs from godef largely in that we do not assume input is a byte position in a Go source file.

Emacs and org-mode integration

The included go-where.el elisp file defines a go-where function that can be called interactively in Emacs, with M-x go-where.

To integrate that with org-mode, you can do this:

(org-add-link-type "go" 'go-where)

And now, in your .org files, a link like [[go:github.com/tv42/where#Ident]] can be opened with mouse or C-c C-o.

Future prospects

If go doc learns to output file positions, go-where may be deprecated in favor of go doc -pos IMPORTPATH IDENT. We'll still need a # separator to support the single input string use case.