internal/lsp: add support for hovering runes

Enable to hover runes found in basic literals in various forms.
When a rune is found, the hover message provides a summary composed of a
printable version (if it exists) of the rune, its codepoint and its name.

Behaviour varies slightly depending on the basic literal: rune literals
always display the summary when hovered, string literals only display it
when an escaped rune sequence is found to avoid providing unnecessary
information, and finally number literals only when expressed as a
hexadecimal number whose size ranges from one to eight bytes.

Fixes golang/go#38239

Change-Id: I024fdd5c511a45c7c285e200ce1eda0669a45491
Reviewed-by: Rebecca Stambler <>
Trust: Rebecca Stambler <>
Trust: Robert Findley <>
Run-TryBot: Rebecca Stambler <>
gopls-CI: kokoro <>
TryBot-Result: Go Bot <>
32 files changed
tree: 0f7594a33874022726b23347f02e0ea665d92f4e
  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
  20. codereview.cfg
  23. go.mod
  24. go.sum

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.


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

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