tools/gopls: add cmd support for signature

This change adds command line support for signatureHelp.
If the location provided corresponds to a function, that
function signature is displayed. In case that function is
documented the related comment is shown as well.

Example:

$ gopls signature ~/tmp/foo/main.go:7:5
$
$ Next(n int) []byte
$
$ Next returns a slice containing the next n bytes from
$ the buffer, advancing the buffer as if the bytes had been
$ returned by Read.

Note that linebreaks shown in the comment are just to adhere
commit message guidelines. The command prints documentation
comments on one line.

Updates golang/go#32875

Change-Id: Ib0dcc3267c594f95d80b74f289c1235c2c0c5f64
Reviewed-on: https://go-review.googlesource.com/c/tools/+/204057
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
5 files changed
tree: afcf912d2740801cfc73fbcab96ab0c4de0326c7
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. gopls/
  9. imports/
  10. internal/
  11. playground/
  12. present/
  13. refactor/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. go.mod
  21. go.sum
  22. LICENSE
  23. PATENTS
  24. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.