diff --git a/cmd/globdraw/main.go b/cmd/globdraw/main.go
index 8ba91f1..585880d 100644
--- a/cmd/globdraw/main.go
+++ b/cmd/globdraw/main.go
@@ -1,64 +1,16 @@
 package main
 
 import (
-	"bytes"
 	"flag"
 	"fmt"
 	"github.com/gobwas/glob"
 	"github.com/gobwas/glob/match"
-	"math/rand"
+	"github.com/gobwas/glob/match/debug"
 	"os"
 	"strings"
 	"unicode/utf8"
 )
 
-func draw(pattern string, m match.Matcher) string {
-	return fmt.Sprintf(`digraph G {graph[label="%s"];%s}`, pattern, graphviz(m, fmt.Sprintf("%x", rand.Int63())))
-}
-
-func graphviz(m match.Matcher, id string) string {
-	buf := &bytes.Buffer{}
-
-	switch matcher := m.(type) {
-	case match.BTree:
-		fmt.Fprintf(buf, `"%s"[label="%s"];`, id, matcher.Value.String())
-		for _, m := range []match.Matcher{matcher.Left, matcher.Right} {
-			switch n := m.(type) {
-			case nil:
-				rnd := rand.Int63()
-				fmt.Fprintf(buf, `"%x"[label="<nil>"];`, rnd)
-				fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
-
-			default:
-				sub := fmt.Sprintf("%x", rand.Int63())
-				fmt.Fprintf(buf, `"%s"->"%s";`, id, sub)
-				fmt.Fprintf(buf, graphviz(n, sub))
-			}
-		}
-
-	case match.AnyOf:
-		fmt.Fprintf(buf, `"%s"[label="AnyOf"];`, id)
-		for _, m := range matcher.Matchers {
-			rnd := rand.Int63()
-			fmt.Fprintf(buf, graphviz(m, fmt.Sprintf("%x", rnd)))
-			fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
-		}
-
-	case match.EveryOf:
-		fmt.Fprintf(buf, `"%s"[label="EveryOf"];`, id)
-		for _, m := range matcher.Matchers {
-			rnd := rand.Int63()
-			fmt.Fprintf(buf, graphviz(m, fmt.Sprintf("%x", rnd)))
-			fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
-		}
-
-	default:
-		fmt.Fprintf(buf, `"%s"[label="%s"];`, id, m.String())
-	}
-
-	return buf.String()
-}
-
 func main() {
 	pattern := flag.String("p", "", "pattern to draw")
 	sep := flag.String("s", "", "comma separated list of separators characters")
@@ -70,12 +22,14 @@ func main() {
 	}
 
 	var separators []rune
-	for _, c := range strings.Split(*sep, ",") {
-		if r, w := utf8.DecodeRuneInString(c); len(c) > w {
-			fmt.Println("only single charactered separators are allowed")
-			os.Exit(1)
-		} else {
-			separators = append(separators, r)
+	if len(*sep) > 0 {
+		for _, c := range strings.Split(*sep, ",") {
+			if r, w := utf8.DecodeRuneInString(c); len(c) > w {
+				fmt.Println("only single charactered separators are allowed")
+				os.Exit(1)
+			} else {
+				separators = append(separators, r)
+			}
 		}
 	}
 
@@ -86,5 +40,5 @@ func main() {
 	}
 
 	matcher := glob.(match.Matcher)
-	fmt.Fprint(os.Stdout, draw(*pattern, matcher))
+	fmt.Fprint(os.Stdout, debug.Graphviz(*pattern, matcher))
 }
diff --git a/match/debug/debug.go b/match/debug/debug.go
new file mode 100644
index 0000000..5c5dbc1
--- /dev/null
+++ b/match/debug/debug.go
@@ -0,0 +1,55 @@
+package debug
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/gobwas/glob/match"
+	"math/rand"
+)
+
+func Graphviz(pattern string, m match.Matcher) string {
+	return fmt.Sprintf(`digraph G {graph[label="%s"];%s}`, pattern, graphviz_internal(m, fmt.Sprintf("%x", rand.Int63())))
+}
+
+func graphviz_internal(m match.Matcher, id string) string {
+	buf := &bytes.Buffer{}
+
+	switch matcher := m.(type) {
+	case match.BTree:
+		fmt.Fprintf(buf, `"%s"[label="%s"];`, id, matcher.Value.String())
+		for _, m := range []match.Matcher{matcher.Left, matcher.Right} {
+			switch n := m.(type) {
+			case nil:
+				rnd := rand.Int63()
+				fmt.Fprintf(buf, `"%x"[label="<nil>"];`, rnd)
+				fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
+
+			default:
+				sub := fmt.Sprintf("%x", rand.Int63())
+				fmt.Fprintf(buf, `"%s"->"%s";`, id, sub)
+				fmt.Fprintf(buf, graphviz_internal(n, sub))
+			}
+		}
+
+	case match.AnyOf:
+		fmt.Fprintf(buf, `"%s"[label="AnyOf"];`, id)
+		for _, m := range matcher.Matchers {
+			rnd := rand.Int63()
+			fmt.Fprintf(buf, graphviz_internal(m, fmt.Sprintf("%x", rnd)))
+			fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
+		}
+
+	case match.EveryOf:
+		fmt.Fprintf(buf, `"%s"[label="EveryOf"];`, id)
+		for _, m := range matcher.Matchers {
+			rnd := rand.Int63()
+			fmt.Fprintf(buf, graphviz_internal(m, fmt.Sprintf("%x", rnd)))
+			fmt.Fprintf(buf, `"%s"->"%x";`, id, rnd)
+		}
+
+	default:
+		fmt.Fprintf(buf, `"%s"[label="%s"];`, id, m.String())
+	}
+
+	return buf.String()
+}
diff --git a/readme.md b/readme.md
index 0f387ee..3e68b52 100644
--- a/readme.md
+++ b/readme.md
@@ -26,13 +26,13 @@ func main() {
     g.Match("api.github.com") // true
     
     // create new glob with set of delimiters as ["."]
-    g = glob.MustCompile("api.*.com", ".")
+    g = glob.MustCompile("api.*.com", '.')
     g.Match("api.github.com") // true
     g.Match("api.gi.hub.com") // false
     
     // create new glob with set of delimiters as ["."]
     // but now with super wildcard
-    g = glob.MustCompile("api.**.com", ".")
+    g = glob.MustCompile("api.**.com", '.')
     g.Match("api.github.com") // true
     g.Match("api.gi.hub.com") // true
         
@@ -42,8 +42,8 @@ func main() {
     g.Match("fat") // true
     g.Match("at") // false
     
-    // create glob with single symbol wildcard and delimiters ["f"]
-    g = glob.MustCompile("?at", "f")
+    // create glob with single symbol wildcard and delimiters ['f']
+    g = glob.MustCompile("?at", 'f')
     g.Match("cat") // true
     g.Match("fat") // false
     g.Match("at") // false