flags pkg : but im not convinced this is right

flags/flags.go

@@ -0,0 +1,24 @@
+package flags
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Flag string
+
+func (f Flag) Dash() string {
+	return fmt.Sprintf("--%s", f)
+}
+
+// prepend --flag to args if a flag isn't there:
+// allows trailing flags:
+// um tag foo --invert
+// becomes:
+// um tag --query foo --invert
+func PrependFlagToArgs(args []string, flag Flag) []string {
+	if len(args) >= 1 && !strings.HasPrefix(args[0], "-") {
+		args = append([]string{flag.Dash()}, args...)
+	}
+	return args
+}

sort/sort.go

@@ -1,10 +1,23 @@
 package sort
 
 import (
+	"flag"
 	"fmt"
+
+	"github.com/brtholomy/um/go/flags"
+)
+
+const (
+	key flags.Flag = "key"
 )
 
 func Sort(args []string) {
-	fmt.Println("sort")
-	fmt.Println(args)
+	sortFlags := flag.NewFlagSet("sort", flag.ExitOnError)
+	sortKey := sortFlags.String(string(key), "", "filename of ordered list to use as key")
+
+	sortFlags.Parse(args)
+	fmt.Println("subcmd sort")
+	fmt.Printf("key: %#v\n", *sortKey)
+	fmt.Printf("args: %#v\n", sortFlags.Args())
+	sortFlags.Usage()
 }

tag/tag.go

@@ -1,10 +1,26 @@
 package tag
 
 import (
+	"flag"
 	"fmt"
+
+	"github.com/brtholomy/um/go/flags"
+)
+
+const (
+	query  flags.Flag = "query"
+	invert flags.Flag = "invert"
 )
 
 func Tag(args []string) {
-	fmt.Println("tag")
-	fmt.Println(args)
+	tagFlags := flag.NewFlagSet("tag", flag.ExitOnError)
+	tagQuery := tagFlags.String(string(query), "", "tag query")
+	tagInvert := tagFlags.Bool(string(invert), false, "invert match")
+
+	tagFlags.Parse(flags.PrependFlagToArgs(args, query))
+
+	fmt.Printf("query: %#v\n", *tagQuery)
+	fmt.Printf("invert: %#v\n", *tagInvert)
+	fmt.Printf("args: %#v\n", tagFlags.Args())
+	tagFlags.Usage()
 }

um.go

@@ -1,10 +1,8 @@
 package main
 
 import (
-	"flag"
 	"fmt"
 	"os"
-	"strings"
 
 	nextpkg "github.com/brtholomy/um/go/next"
 	sortpkg "github.com/brtholomy/um/go/sort"
@@ -22,38 +20,7 @@ const (
 
 var help string = fmt.Sprintf("um [%s | %s | %s | %s]", tag, next, last, sort)
 
-type Flag string
-
-const (
-	query  Flag = "query"
-	invert Flag = "invert"
-	key    Flag = "key"
-)
-
-func (f Flag) Dash() string {
-	return fmt.Sprintf("--%s", f)
-}
-
-// prepend --flag to args if a flag isn't there:
-// allows trailing flags:
-// um tag foo --invert
-// becomes:
-// um tag --query foo --invert
-func prependFlagToArgs(args []string, flag Flag) []string {
-	if len(args) >= 1 && !strings.HasPrefix(args[0], "-") {
-		args = append([]string{flag.Dash()}, args...)
-	}
-	return args
-}
-
 func main() {
-	tagFlags := flag.NewFlagSet(string(tag), flag.ExitOnError)
-	tagQuery := tagFlags.String(string(query), "", "tag query")
-	tagInvert := tagFlags.Bool(string(invert), false, "invert match")
-
-	sortFlags := flag.NewFlagSet(string(sort), flag.ExitOnError)
-	sortKey := sortFlags.String(string(key), "", "filename of ordered list to use as key")
-
 	// TODO: do something useful:
 	// run empty tag query?
 	if len(os.Args) < 2 {
@@ -70,20 +37,9 @@ func main() {
 	case last:
 		nextpkg.Last()
 	case tag:
-		// TODO: move flag defs to the package?
-		tagFlags.Parse(prependFlagToArgs(args, query))
 		tagpkg.Tag(args)
-		fmt.Printf("query: %#v\n", *tagQuery)
-		fmt.Printf("invert: %#v\n", *tagInvert)
-		fmt.Printf("args: %#v\n", tagFlags.Args())
-		tagFlags.Usage()
 	case sort:
-		sortFlags.Parse(args)
 		sortpkg.Sort(args)
-		fmt.Println("subcmd sort")
-		fmt.Printf("key: %#v\n", *sortKey)
-		fmt.Printf("args: %#v\n", sortFlags.Args())
-		sortFlags.Usage()
 	default:
 		fmt.Println(help)
 		os.Exit(1)