Add StringSetCSV

.travis.yml

@@ -1,4 +1,4 @@
 language: go
 go:
   - "1.10"
-script: go test ./...
+script: go test ./...

README.md

@@ -1,8 +1,8 @@
-# flagvar 
+# flagvar
 
 [![](https://godoc.org/github.com/sgreben/flagvar?status.svg)](http://godoc.org/github.com/sgreben/flagvar) [![](https://goreportcard.com/badge/github.com/sgreben/flagvar/goreportcard)](https://goreportcard.com/report/github.com/sgreben/flagvar) [![cover.run](https://cover.run/go/github.com/sgreben/flagvar.svg?style=flat&tag=golang-1.10)](https://cover.run/go?tag=golang-1.10&repo=github.com%2Fsgreben%2Fflagvar) [![Build Status](https://travis-ci.org/sgreben/flagvar.svg?branch=master)](https://travis-ci.org/sgreben/flagvar)
 
-A collection of CLI argument types for the `flag` package. 
+A collection of CLI argument types for the `flag` package.
 
 ```go
 import "github.com/sgreben/flagvar"
@@ -16,7 +16,7 @@ import "github.com/sgreben/flagvar/enum"
 var enums flagvar.EnumsCSV
 ```
 
-Or just copy & paste what you need. It's public domain. 
+Or just copy & paste what you need. It's public domain.
 
 <!-- TOC -->
 
@@ -53,7 +53,7 @@ func main() {
 ```
 
 ```sh
-$ go run main.go -set abc=xyz -url https://github.com 
+$ go run main.go -set abc=xyz -url https://github.com
 # no error
 
 $ go run main.go -set abc=xyz -url ://github.com
@@ -116,6 +116,7 @@ Here's a compact overview:
 | [Regexps](https://godoc.org/github.com/sgreben/flagvar#Regexps)       | [a-z]+          | []*regexp.Regexp                            |
 | [Strings](https://godoc.org/github.com/sgreben/flagvar#Strings)     | "xyxy"             | []string                             |
 | [StringSet](https://godoc.org/github.com/sgreben/flagvar#StringSet)  | "xyxy"             | []string                             |
+| [StringSetCSV](https://godoc.org/github.com/sgreben/flagvar#StringSetCSV)       | y,x,y              | []string                             |
 | [TCPAddr](https://godoc.org/github.com/sgreben/flagvar#TCPAddr)        | 127.0.0.1:10               | net.TCPAddr                              |
 | [TCPAddrs](https://godoc.org/github.com/sgreben/flagvar#TCPAddrs)        | 127.0.0.1:10               | []net.TCPAddr                              |
 | [TCPAddrsCSV](https://godoc.org/github.com/sgreben/flagvar#TCPAddrsCSV)        | 127.0.0.1:10,:123               | []net.TCPAddr                              |
@@ -151,4 +152,4 @@ Here's a compact overview:
 - Support "blind" usage
     - Zero values should be useful
     - Avoid introducing failure cases, handle any combination of parameters gracefully.
-    - All "obvious things to try" should work.
+    - All "obvious things to try" should work.

string.go

@@ -1,6 +1,7 @@
 package flagvar
 
 import (
+	"fmt"
 	"sort"
 	"strings"
 )
@@ -47,3 +48,49 @@ func (fv *StringSet) Set(v string) error {
 func (fv *StringSet) String() string {
 	return strings.Join(fv.Values(), ",")
 }
+
+// StringSetCSV is a `flag.Value` for comma-separated string arguments.
+// If `Accumulate` is set, the values of all instances of the flag are accumulated.
+// The `Separator` field is used instead of the comma when set.
+// If `CaseSensitive` is set to `true` (default `false`), the comparison is case-sensitive.
+type StringSetCSV struct {
+	Separator  string
+	Accumulate bool
+
+	Value  map[string]bool
+	Values []string
+}
+
+// Help returns a string suitable for inclusion in a flag help message.
+func (fv *StringSetCSV) Help() string {
+	separator := ","
+	if fv.Separator != "" {
+		separator = fv.Separator
+	}
+	return fmt.Sprintf("%q-separated list of strings", separator)
+}
+
+// Set is flag.Value.Set
+func (fv *StringSetCSV) Set(v string) error {
+	separator := fv.Separator
+	if separator == "" {
+		separator = ","
+	}
+	if !fv.Accumulate || fv.Value == nil {
+		fv.Value = make(map[string]bool)
+	}
+	parts := strings.Split(v, separator)
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		if fv.Value[part] {
+			continue
+		}
+		fv.Value[part] = true
+		fv.Values = append(fv.Values, part)
+	}
+	return nil
+}
+
+func (fv *StringSetCSV) String() string {
+	return strings.Join(fv.Values, ",")
+}

string_test.go

@@ -35,3 +35,31 @@ func TestStringSet(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func TestStringSetCSV(t *testing.T) {
+	fv := flagvar.StringSetCSV{Accumulate: true}
+	var fs flag.FlagSet
+	fs.Var(&fv, "string-set-csv", "")
+
+	err := fs.Parse([]string{"-string-set-csv", "first,second", "-string-set-csv", "first"})
+	if err != nil {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(fv.Values, []string{"first", "second"}) {
+		t.Fail()
+	}
+}
+
+func TestStringSetCSVSeparator(t *testing.T) {
+	fv := flagvar.StringSetCSV{Separator: ";", Accumulate: true}
+	var fs flag.FlagSet
+	fs.Var(&fv, "string-set-csv", "")
+
+	err := fs.Parse([]string{"-string-set-csv", "first;second", "-string-set-csv", "first"})
+	if err != nil {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(fv.Values, []string{"first", "second"}) {
+		t.Fail()
+	}
+}