Merge pull request #111 from xushiwei/t

stringutil: NewBuilderSize

stringutil/build.go

@@ -24,7 +24,12 @@ type Builder struct {
 }
 
 // NewBuilder creates a new Builder object.
-func NewBuilder(ncap int) *Builder {
+func NewBuilder(b []byte) *Builder {
+	return &Builder{b: b}
+}
+
+// NewBuilderSize creates a new Builder object whose buffer has at least the specified size.
+func NewBuilderSize(ncap int) *Builder {
 	return &Builder{b: make([]byte, 0, ncap)}
 }
 

stringutil/concat.go

@@ -18,6 +18,9 @@ package stringutil
 
 // Concat concatenates parts of a string together.
 func Concat(parts ...string) string {
+	if len(parts) == 1 {
+		return parts[0]
+	}
 	n := 0
 	for _, part := range parts {
 		n += len(part)

stringutil/string_test.go

@@ -23,16 +23,19 @@ import (
 )
 
 func TestConcat(t *testing.T) {
+	if ret := Concat("1"); ret != "1" {
+		t.Fatal("Concat(1):", ret)
+	}
 	if ret := Concat("1", "23", "!"); ret != "123!" {
 		t.Fatal("Concat:", ret)
 	}
 }
 
 func TestBuild(t *testing.T) {
-	if ret := NewBuilder(0).Build(); ret != "" {
+	if ret := NewBuilder(nil).Build(); ret != "" {
 		t.Fatal("NewBuilder(0):", ret)
 	}
-	if ret := NewBuilder(16).Add("1").AddByte('2', '3').AddByte('!').Build(); ret != "123!" {
+	if ret := NewBuilderSize(16).Add("1").AddByte('2', '3').AddByte('!').Build(); ret != "123!" {
 		t.Fatal("TestBuild:", ret)
 	}
 }