initial implementation, coming from dflag MR and delta actually

.github/dependabot.yml

@@ -0,0 +1,16 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "gomod"
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "daily"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"

.github/workflows/codecov.yml

@@ -0,0 +1,21 @@
+name: "Code Coverage"
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - uses: actions/setup-go@v3
+      with:
+          go-version: '1.19'
+    - name: Run test coverage
+      run: go test -race -coverprofile=coverage.out -covermode=atomic ./...
+    - uses: codecov/codecov-action@v3
+      with:
+        files: coverage.out

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,67 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ main ]
+  schedule:
+    - cron: '42 20 * * 3'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
+        # Learn more about CodeQL language support at https://aka.ms/codeql-docs/language-support
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@755da8c3cf115ac066823e79a1e1788f8940201b # pin@v3
+
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@17573ee1cc1b9d061760f3a006fc4aac4f944fd5 # pin@v2
+        with:
+          languages: ${{ matrix.language }}
+          # If you wish to specify custom queries, you can do so here or in a config file.
+          # By default, queries listed here will override any specified in a config file.
+          # Prefix the list here with "+" to use these queries and those in the config file.
+          # Details on CodeQL's query packs refer to : https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#using-queries-in-ql-packs
+          # queries: security-extended,security-and-quality
+
+      # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+      # If this step fails, then you should remove it and run the build manually (see below)
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@17573ee1cc1b9d061760f3a006fc4aac4f944fd5 # pin@v2
+
+      # ℹ️ Command-line programs to run using the OS shell.
+      # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
+      #   If the Autobuild fails above, remove it and uncomment the following three lines. 
+      #   modify them (or add more) to build your code if your project, please refer to the EXAMPLE below for guidance.
+      # - run: |
+      #   echo "Run, Build Application using script"
+      #   ./location_of_script_within_repo/buildscript.sh
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@17573ee1cc1b9d061760f3a006fc4aac4f944fd5 # pin@v2

.golangci.yml

@@ -0,0 +1,176 @@
+# Config for golanglint-ci
+
+# output configuration options
+
+# all available settings of specific linters
+linters-settings:
+  gocritic:
+    disabled-checks:
+      - ifElseChain
+  dupl:
+    # tokens count to trigger issue, 150 by default
+    threshold: 100
+  exhaustive:
+    # indicates that switch statements are to be considered exhaustive if a
+    # 'default' case is present, even if all enum members aren't listed in the
+    # switch
+    default-signifies-exhaustive: false
+  funlen:
+    lines: 140
+    statements: 70
+  gocognit:
+    # minimal code complexity to report, 30 by default (but we recommend 10-20)
+    min-complexity: 42
+  nestif:
+    # minimal complexity of if statements to report, 5 by default
+    min-complexity: 4
+  gocyclo:
+    # minimal code complexity to report, 30 by default (but we recommend 10-20)
+    min-complexity: 30
+  godot:
+    # check all top-level comments, not only declarations
+    check-all: false
+  govet:
+    # report about shadowed variables
+    check-shadowing: true
+    # settings per analyzer
+    settings:
+      printf: # analyzer name, run `go tool vet help` to see all analyzers
+        funcs: # run `go tool vet help printf` to see available settings for `printf` analyzer
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Infof
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Warnf
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Errorf
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Fatalf
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Printf
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).FErrf
+    enable-all: true
+    disable-all: false
+  depguard:
+    list-type: blacklist
+    include-go-root: false
+    packages:
+      - github.com/sirupsen/logrus
+    packages-with-error-message:
+      # specify an error message to output when a blacklisted package is used
+      - github.com/sirupsen/logrus: "logging is allowed only by fortio.log"
+  lll:
+    # max line length, lines longer will be reported. Default is 120.
+    # '\t' is counted as 1 character by default, and can be changed with the tab-width option
+    line-length: 132
+    # tab width in spaces. Default to 1.
+    tab-width: 1
+  misspell:
+    # Correct spellings using locale preferences for US or UK.
+    # Default is to use a neutral variety of English.
+    # Setting locale to US will correct the British spelling of 'colour' to 'color'.
+    locale: US
+    ignore-words:
+      - fortio
+  nakedret:
+    # make an issue if func has more lines of code than this setting and it has naked returns; default is 30
+    max-func-lines: 30
+  nolintlint:
+    require-specific: true
+  whitespace:
+    multi-if: false   # Enforces newlines (or comments) after every multi-line if statement
+    multi-func: false # Enforces newlines (or comments) after every multi-line function signature
+  gofumpt:
+    # Choose whether or not to use the extra rules that are disabled
+    # by default
+    extra-rules: false
+
+
+linters:
+  disable:
+    # bad ones:
+    - musttag
+    # Deprecated ones:
+    - scopelint
+    - golint
+    - interfacer
+    - maligned
+    - varcheck
+    - structcheck
+    - nosnakecase
+    - deadcode
+    # Weird/bad ones:
+    - wsl
+    - nlreturn
+    - gochecknoinits
+    - gochecknoglobals
+    - gomnd
+    - testpackage
+    - wrapcheck
+    - exhaustivestruct
+    - tagliatelle
+    - nonamedreturns
+    - varnamelen
+    - exhaustruct # seems like a good idea at first but actually a pain and go does have zero values for a reason.
+# TODO consider putting these back, when they stop being bugged (ifshort, wastedassign,...)
+    - paralleltest
+    - thelper
+    - forbidigo
+    - ifshort
+    - wastedassign
+    - cyclop
+    - forcetypeassert
+    - ireturn
+  enable-all: true
+  disable-all: false
+  # Must not use fast: true in newer golangci-lint or it'll just skip a bunch of linter instead of doing caching like before (!)
+  fast: false
+
+
+issues:
+  # Excluding configuration per-path, per-linter, per-text and per-source
+  exclude-rules:
+    # Exclude some linters from running on tests files.
+    - path: _test\.go
+      linters:
+        - gocyclo
+        - errcheck
+        - dupl
+        - gosec
+        - gochecknoinits
+        - gochecknoglobals
+        - forcetypeassert
+        - nosnakecase
+        - noctx
+
+    # Exclude lll issues for long lines with go:generate
+    - linters:
+        - lll
+      source: "^//go:generate "
+    - linters:
+        - goerr113
+      text: "do not define dynamic errors"
+    - linters:
+        - govet
+      text: "fieldalignment:"
+    - linters:
+        - godox
+      text: "TODO"
+    - linters:
+        - nosnakecase
+      text: "grpc_|_SERVING|O_"
+
+  # Maximum issues count per one linter. Set to 0 to disable. Default is 50.
+  max-issues-per-linter: 0
+
+  # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
+  max-same-issues: 0
+
+severity:
+  # Default value is empty string.
+  # Set the default severity for issues. If severity rules are defined and the issues
+  # do not match or no severity is provided to the rule this will be the default
+  # severity applied. Severities should match the supported severity names of the
+  # selected out format.
+  # - Code climate: https://docs.codeclimate.com/docs/issues#issue-severity
+  # -   Checkstyle: https://checkstyle.sourceforge.io/property_types.html#severity
+  # -       Github: https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message
+  default-severity: error
+
+  # The default value is false.
+  # If set to true severity-rules regular expressions become case sensitive.
+  case-sensitive: false

README.md

@@ -1,2 +1,7 @@
+[![Go Reference](https://pkg.go.dev/badge/fortio.org/sets.svg)](https://pkg.go.dev/fortio.org/sets)
+[![Go Report Card](https://goreportcard.com/badge/fortio.org/sets)](https://goreportcard.com/report/fortio.org/sets)
+[![GitHub Release](https://img.shields.io/github/release/fortio/sets.svg?style=flat)](https://github.com/fortio/sets/releases/)
+[![Coverage](https://codecov.io/github/fortio/delta/branch/main/graph/badge.svg?token=LONYZDFQ7C)](https://codecov.io/github/fortio/sets)
+
 # sets
-Sets and Set operations in golang (ie map[T]struct{} but with helper/nicer names, hiding the struct{}{}...)
+Sets and Set operations in golang (ie `map[T]struct{}` but with helper functions/nicer names, hiding the `struct{}{}` etc...)

go.mod

@@ -0,0 +1,5 @@
+module fortio.org/sets
+
+go 1.19
+
+require fortio.org/assert v1.1.4

go.sum

@@ -0,0 +1,2 @@
+fortio.org/assert v1.1.4 h1:Za1RaG+OjsTMpQS3J3UCvTF6wc4+IOHCz+jAOU37Y4o=
+fortio.org/assert v1.1.4/go.mod h1:039mG+/iYDPO8Ibx8TrNuJCm2T2SuhwRI3uL9nHTTls=

sets.go

@@ -0,0 +1,81 @@
+// (Fortio) Sets.
+//
+// (c) 2023 Fortio Authors
+// See LICENSE
+
+// Sets and Set type and operations in go 1.18+ generics.
+// (pending built in support in golang core)
+package sets // import "fortio.org/sets"
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+type Set[T comparable] map[T]struct{}
+
+// SetFromSlice constructs a Set from a slice.
+func FromSlice[T comparable](items []T) Set[T] {
+	// best pre-allocation if there are no duplicates
+	res := make(map[T]struct{}, len(items))
+	for _, item := range items {
+		res[item] = struct{}{}
+	}
+	return res
+}
+
+func (s Set[T]) Clone() Set[T] {
+	res := make(Set[T], len(s))
+	for k := range s {
+		res.Add(k)
+	}
+	return res
+}
+
+func (s Set[T]) Add(item ...T) {
+	for _, i := range item {
+		s[i] = struct{}{}
+	}
+}
+
+func (s Set[T]) Has(item T) bool {
+	_, found := s[item]
+	return found
+}
+
+func (s Set[T]) Remove(item ...T) {
+	for _, i := range item {
+		delete(s, i)
+	}
+}
+
+func New[T comparable](item ...T) Set[T] {
+	res := make(Set[T], len(item))
+	res.Add(item...)
+	return res
+}
+
+func (s Set[T]) String() string {
+	keys := make([]string, 0, len(s))
+	for k := range s {
+		keys = append(keys, fmt.Sprintf("%v", k))
+	}
+	sort.Strings(keys)
+	return  strings.Join(keys, ",")
+}
+
+// RemoveCommon removes elements from both sets that are in both,
+// leaving only the delta. Useful for Notifier on Set so that
+// oldValue has what has been removed and newValue has what has been added.
+func RemoveCommon[T comparable](a, b Set[T]) {
+	if len(a) > len(b) {
+		a, b = b, a
+	}
+	for e := range a {
+		if _, found := b[e]; found {
+			delete(a, e)
+			delete(b, e)
+		}
+	}
+}