bazel-generics.txt

To set up the Go repo

git clone https://go.googlesource.com/go
cd go
git checkout dev.typeparams
cd src
./make.bash

Use that directory with go_local_sdk in WORKSPACE.

-- WORKSPACE --
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "io_bazel_rules_go",
    sha256 = "69de5c704a05ff37862f7e0f5534d4f479418afc21806c887db544a316f3cb6b",
    urls = [
        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.27.0/rules_go-v0.27.0.tar.gz",
        "https://github.com/bazelbuild/rules_go/releases/download/v0.27.0/rules_go-v0.27.0.tar.gz",
    ],
)

load("@io_bazel_rules_go//go:deps.bzl", "go_local_sdk", "go_register_toolchains", "go_rules_dependencies")

go_rules_dependencies()

go_local_sdk(
    name = "go_sdk",
    path = "/Users/jayconrod/goroot",
)

go_register_toolchains()

-- BUILD.bazel --
load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")

go_binary(
    name = "hello",
    embed = [":hello_lib"],
    visibility = ["//visibility:public"],
)

go_library(
    name = "hello_lib",
    srcs = ["hello.go"],
    gc_goopts = ["-G=3"],
    importpath = "example.com/hello",
    visibility = ["//visibility:private"],
    deps = ["//length"],
)
-- hello.go --
package main

import (
	"fmt"
	"length"
)

func main() {
	a := []string{"a", "b"}
	b := []int{1, 2, 3, 4}
	fmt.Println(length.Len(a))
	fmt.Println(length.Len(b))
}
-- length/BUILD.bazel --
load("@io_bazel_rules_go//go:def.bzl", "go_library")

go_library(
    name = "length",
    srcs = ["length.go"],
    gc_goopts = ["-G=3"],
    importpath = "length",
    visibility = ["//visibility:public"],
)
-- length/length.go --
package length

func Len[T any](s []T) int {
	return len(s)
}