lsp/completion: reorganize how we track candidate type mods

"type mod" refers to agglutinative expressions such as dereference
"*", invocation "()", and slicing "[:]". When considering an object as
a completion candidate, we check whether applying a type mod would
make it a better candidate.

Previously we tracked the type mods we wanted to apply to a candidate
by setting bool fields. Now instead we keep a slice of the type mods.
This has two main advantages:
- The mods are now ordered which will allow us to format candidates
  properly when the same mods can appear in different order (e.g.
  "<-*foo" or *<-foo").
- We can now record any mod multiple times allowing for "<-<-foo" or
  "foo()()".

I changed the formatting code to always create a snippet object since
that made things simpler. I had to tweak a few snippet helper methods
to accept a snippet argument rather than creating a new snippet.

This commit's only functional change is that we no longer show any
type mods in candidate labels. For example, the user will now see
"foo" in the completion popup instead of "*foo". Showing the operators
adds noise to the candidate list, and we didn't display them
consistently.

Updates golang/go#46045.

Change-Id: I3ea7baa1ee2fee80a1f8cfe88cbae1093ae269ba
Reviewed-on: https://go-review.googlesource.com/c/tools/+/323449
Run-TryBot: Muir Manders <muir@mnd.rs>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Trust: Rebecca Stambler <rstambler@golang.org>
14 files changed
tree: ecbeb295ac7729fa97eedac6c64f45a1af696ffe
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. copyright/
  6. cover/
  7. go/
  8. godoc/
  9. gopls/
  10. imports/
  11. internal/
  12. playground/
  13. present/
  14. refactor/
  15. txtar/
  16. .gitattributes
  17. .gitignore
  18. .prettierrc
  19. AUTHORS
  20. codereview.cfg
  21. CONTRIBUTING.md
  22. CONTRIBUTORS
  23. go.mod
  24. go.sum
  25. LICENSE
  26. PATENTS
  27. README.md
README.md

Go Tools

PkgGoDev

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.

JS/CSS Formatting

This repository uses prettier to format JS and CSS files.

The version of prettier used is 1.18.2.

It is encouraged that all JS and CSS code be run through this before submitting a change. However, it is not a strict requirement enforced by CI.

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.