feat: update for 2024

This contains a bunch of small updates and changes.

+ Add go.mod file
+ Add Makefile, linters, and GitHub action
+ Update LICENSE and README
+ Add TODO
+ Make some initial changes to the code

.github/workflows/go.yml

@@ -0,0 +1,23 @@
+name: gitmirror test
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+        go: ['1.22', '1.23']
+    name: humane test (using go ${{ matrix.go }} on ${{ matrix.os }})
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go }}
+      - run: make test

.golangci.yml

@@ -0,0 +1,78 @@
+linters-settings:
+  copyloopvar:
+    check-alias: true
+  errcheck:
+    check-type-assertions: true
+    check-blank: true
+    exclude-functions:
+      - fmt.Printf
+      - fmt.Println
+      - fmt.Fprintf
+      - fmt.Fprintln
+      - (*flag.FlagSet).Set
+  exhaustive:
+    default-signifies-exhaustive: true
+  goconst:
+    min-len: 2
+    min-occurrences: 3
+  gocritic:
+    disabled-checks:
+      - hugeParam
+    enabled-tags:
+      - diagnostic
+      - experimental
+      - opinionated
+      - performance
+      - style
+  govet:
+    enable-all: true
+    shadow:
+      strict: true
+  nolintlint:
+    require-explanation: true
+    require-specific: true
+
+linters:
+  disable-all: true
+  enable:
+    - bodyclose
+    - copyloopvar
+    - cyclop
+    - dogsled
+    - dupl
+    - errcheck
+    - errchkjson
+    - errname
+    - errorlint
+    - exhaustive
+    - goconst
+    - gocritic
+    - gosec
+    - gosimple
+    - govet
+    - ineffassign
+    - ireturn
+    - maintidx
+    - misspell
+    - nolintlint
+    - nakedret
+    - prealloc
+    - predeclared
+    - stylecheck
+    - thelper
+    - typecheck
+    - unconvert
+    - unparam
+    - unused
+    - whitespace
+
+run:
+  concurrency: 8
+  issues-exit-code: 1
+  timeout: 30m
+  tests: true
+  allow-parallel-runners: false
+
+issues:
+  exclude-dirs:
+    - internal

LICENSE

@@ -1,4 +1,5 @@
 Copyright (c) 2009 The Go Authors. All rights reserved.
+Copyright (c) 2024 Peter Aronoff. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are

Makefile

@@ -0,0 +1,39 @@
+.DEFAULT_GOAL := test
+
+fmt:
+	golangci-lint run --disable-all --no-config -Egofmt --fix
+	golangci-lint run --disable-all --no-config -Egofumpt --fix
+
+lint: fmt
+	staticcheck ./...
+	revive -config revive.toml ./...
+	golangci-lint run
+
+golangci: fmt
+	golangci-lint run
+
+staticcheck: fmt
+	staticcheck ./...
+
+revive: fmt
+	revive -config revive.toml ./...
+
+test:
+	go test -shuffle on .
+
+testv:
+	go test -shuffle on -v .
+
+testr:
+	go test -race -shuffle on .
+
+build: lint testr
+	go build .
+
+install: build
+	go install .
+
+clean:
+	go clean -i -r -cache
+
+.PHONY: fmt lint build install test testv testr clean

README.md

@@ -1,54 +1,66 @@
-# rsc.io/getopt
+# getopt (forked from rsc.io/getopt)
 
-[For full package documentation, see [https://godoc.org/rsc.io/getopt](https://godoc.org/rsc.io/getopt).]
+## Note
 
-    package getopt // import "rsc.io/getopt"
+This repository is a fork of [rsc's][rsc] [getopt][rgetopt].  I have
+updated the code in various ways, and I will probably continue to do so.  But
+the core idea (and implementation) is his rather than mine. td;dr — credit where
+credit is due, but all mistakes and bad ideas are my fault and not rsc's.
 
-Package getopt parses command lines using [_getopt_(3)](http://man7.org/linux/man-pages/man3/getopt.3.html) syntax. It is a
-replacement for `flag.Parse` but still expects flags themselves to be defined
-in package flag.
+[rsc]: https://github.com/rsc
+[rgetopt]: https://github.com/rsc/getopt
 
-Flags defined with one-letter names are available as short flags (invoked
-using one dash, as in `-x`) and all flags are available as long flags (invoked
-using two dashes, as in `--x` or `--xylophone`).
+## Introduction
 
-To use, define flags as usual with [package flag](https://godoc.org/flag). Then introduce any aliases
-by calling `getopt.Alias`:
+Package getopt parses command lines using [`getopt_(3)`][getopt3] syntax.  It is
+a replacement for [`FlagSet.Parse`][fs.Parse] but still expects flags themselves
+to be defined in package `flag`.
 
-    getopt.Alias("v", "verbose")
+[getopt3]: http://man7.org/linux/man-pages/man3/getopt.3.html
+[fs.Parse]: https://pkg.go.dev/flag#FlagSet.Parse
 
-Or call `getopt.Aliases` to define a list of aliases:
+Flags defined with one-letter names are available as short flags (invoked using
+one dash, as in `-x`) and all flags are available as long flags (invoked using
+two dashes, as in `--x` or `--xylophone`).
 
-    getopt.Aliases(
-    	"v", "verbose",
-    	"x", "xylophone",
-    )
+To use, define a [`FlagSet`][FlagSet] and flags as usual with [package
+flag][flag].  Then introduce any aliases by calling `getopt.Alias`:
 
-One name in each pair must already be defined in package flag (so either
-"v" or "verbose", and also either "x" or "xylophone").
+```go
+type cfg struct {
+	quiet bool
+	verbose  bool
+}
 
-Then parse the command-line:
+func main() {
+	fs := getopt.NewFlagSet("awesome", flag.ContinueOnError)
+	cfg := &cfg{}
 
-    getopt.Parse()
+	fs.BoolVar(&cfg.quiet, "quiet", false, "Print only errors")
+	fs.BoolVar(&cfg.help, "v", false, "Print way too much")
 
-If it encounters an error, `Parse` calls `flag.Usage` and then exits the
-program.
+	getopt.Alias("v", "verbose")
+	getopt.Alias("q", "quiet")
+}
+```
 
-When writing a custom `flag.Usage` function, call `getopt.PrintDefaults` instead
-of `flag.PrintDefaults` to get a usage message that includes the
-names of aliases in flag descriptions.
+Or call `getopt.Aliases` to define a list of aliases:
 
-At initialization time, package getopt installs a new `flag.Usage` that is the same
-as the default `flag.Usage` except that it calls `getopt.PrintDefaults` instead
-of `flag.PrintDefaults`.
+```go
+getopt.Aliases(
+	"q", "quiet",
+	"v", "verbose",
+)
+```
 
-This package also defines a `FlagSet` wrapping the standard `flag.FlagSet`.
+[FlagSet]: https://pkg.go.dev/flag#FlagSet
+[flag]: https://godoc.org/flag
 
-## Caveat
+One name in each pair must already be defined in package `flag` (so either
+"q" or "quiet", and also either "v" or "verbose").
 
-In general Go flag parsing is preferred for new programs, because it is not
-as pedantic about the number of dashes used to invoke a flag (you can write
-`-verbose` or `--verbose` and the program does not care). This package is meant
-to be used in situations where, for legacy reasons, it is important to use
-exactly _getopt_(3) syntax, such as when rewriting in Go an existing tool that
-already uses _getopt_(3).
+Then parse the command-line using [`fs.Parse()`][fs.Parse].
+
+When writing a custom `flag.Usage` function, call `getopt.PrintDefaults` instead
+of `flag.PrintDefaults` to get a usage message that includes the names of
+aliases in flag descriptions.

TODO.md

@@ -0,0 +1,23 @@
+# TODO
+
+1. Improve and expand tests.
+    + Use example tests or cmp to test usage output.
+    + Add tests for defaults and isZero check.
+    + Check coverage?
+1. Change usage display to suit my preferences.  Do not special case short
+   boolean flags; put usage on the same line as the flag. Use a tabwriter and
+   wrap text to some good default for terminals?
+1. Use a generic isZero check rather than reflect?
+1. Add `Subcommand` and `Subcommands` (similar to `Alias` and `Aliases`).  These
+   would support display of subcommands in usage, but I do not want to handle
+   the overall parsing or running of subcommands (for now?).  Users will
+   manually parse and run their subcommands.
+1. Read both `flag` and `ff`.  Decide how I want to implement both long and
+   short.  Do I want to use something like `Alias` and the stdlib, or should
+   I do it from scratch.  Also, think about how I want to implement help
+   displays and how much of the stdlib is worth carrying over.  E.g., `Visit`
+   and `VisitAll`.
+1. Demand that all flags implement an interface with two methods: `IsZero` and
+   `Default`?  (Maybe call this a `Defaulter` interface?)  This could get rid of
+   brittle, incomplete, `panic`-inducing, or `reflect`-requiring tests for
+   whether something is a zero value.