x/tools/gopls: completion and quick fix for filling in type parameters in generic types

[suzmue]

gopls version

Build info ---------- golang.org/x/tools/gopls v0.14.2 golang.org/x/tools/gopls@v0.14.2 h1:sIw6vjZiuQ9S7s0auUUkHlWgsCkKZFWDHmrge8LYsnc= github.com/BurntSushi/toml@v1.2.1 h1:9F2/+DoOYIOksmaJFPw1tGFy1eDnIJXg+UHjuD8lTak= github.com/google/go-cmp@v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38= github.com/sergi/go-diff@v1.1.0 h1:we8PVUC3FE2uYfodKH/nBHMSetSfHDR6scGdBi+erh0= golang.org/x/exp/typeparams@v0.0.0-20221212164502-fae10dda9338 h1:2O2DON6y3XMJiQRAS1UWU+54aec2uopH3x7MAiqGW6Y= golang.org/x/mod@v0.14.0 h1:dGoOF9QVLYng8IHTm7BAyWqCqSheQ5pYWGhzW00YJr0= golang.org/x/sync@v0.4.0 h1:zxkM55ReGkDlKSM+Fu41A+zmbZuaPVbGMzvvdUPznYQ= golang.org/x/sys@v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q= golang.org/x/telemetry@v0.0.0-20231114163143-69313e640400 h1:brbkEFfGwNGAEkykUOcryE/JiHUMMJouzE0fWWmz/QU= golang.org/x/text@v0.13.0 h1:ablQoSUd0tRdKxZewP80B+BaqeKJuVhuRxj/dkrun3k= golang.org/x/tools@v0.14.1-0.20231114185516-c9d3e7de13fd h1:Oku7E+OCrXHyst1dG1z10etCTxewCHXNFLRlyMPbh3w= golang.org/x/vuln@v1.0.1 h1:KUas02EjQK5LTuIx1OylBQdKKZ9jeugs+HiqO5HormU= honnef.co/go/tools@v0.4.5 h1:YGD4H+SuIOOqsyoLOpZDWcieM28W47/zRO7f+9V3nvo= mvdan.cc/gofumpt@v0.4.0 h1:JVf4NN1mIpHogBj7ABpgOyZc65/UUOkKQFkoURsz4MM= mvdan.cc/xurls/v2@v2.4.0 h1:tzxjVAj+wSBmDcF6zBB7/myTy3gX9xvi8Tyr28AuQgc= go: go1.21.1

go env

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/Users/suzmue/Library/Caches/go-build'
GOENV='/Users/suzmue/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/suzmue/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/suzmue/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/suzmue/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.21.2.darwin-amd64'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/suzmue/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.21.2.darwin-amd64/pkg/tool/darwin_amd64'
GOVCS=''
GOVERSION='go1.21.2'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/Users/suzmue/helloWorld/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/2x/hlwbwjzd1vd4brlfs80676fw00fkl_/T/go-build1491560032=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

main.go:

package main

import "fmt"

type A[T any] struct {
	foo T
}

type B[T any] struct {
	foo []T
}

func main() {
	var a *A[int] = new(A) // diagnostic: "cannot use generic type A[T any] without instantiation"
	a.foo = 1
	a2 := &A{ // diagnostic: "cannot use generic type A[T any] without instantiation"
		foo: "hello",
	}
	fmt.Printf("%d %s\n", a.foo, a2.foo)
	b := B{ // diagnostic: "cannot use generic type B[T any] without instantiation"
		foo: []int{1, 2, 3},
	}
	fmt.Printf("%d\n", len(b.foo))
}

What did you expect to see?

1. Completions with the correct type when adding [ when filling in the type parameters.
2. Quick Fix for adding the missing type parameter which can be inferred in these cases.

What did you see instead?

No quick fixes available and completions were for other types (same order for all):

Editor and settings

VS Code

Logs

No response