From 1698ae2bb19c0a108e337ea292cbef42bf002805 Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Sun, 25 Feb 2024 23:37:54 +0800
Subject: [PATCH 1/2] stringutil: NewBuilderSize

---
 stringutil/build.go       | 7 ++++++-
 stringutil/string_test.go | 4 ++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/stringutil/build.go b/stringutil/build.go
index 38b82a9..00def6f 100644
--- a/stringutil/build.go
+++ b/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)}
 }
 
diff --git a/stringutil/string_test.go b/stringutil/string_test.go
index 168d335..9415d10 100644
--- a/stringutil/string_test.go
+++ b/stringutil/string_test.go
@@ -29,10 +29,10 @@ func TestConcat(t *testing.T) {
 }
 
 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)
 	}
 }

From 22936bfbd9443bdb72aa3a4d9ee7092d8ef6969e Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Sun, 25 Feb 2024 23:47:39 +0800
Subject: [PATCH 2/2] stringutil.Concat: len(parts) == 1

---
 stringutil/concat.go      | 3 +++
 stringutil/string_test.go | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/stringutil/concat.go b/stringutil/concat.go
index 7944b01..007b228 100644
--- a/stringutil/concat.go
+++ b/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)
diff --git a/stringutil/string_test.go b/stringutil/string_test.go
index 9415d10..81e9b5e 100644
--- a/stringutil/string_test.go
+++ b/stringutil/string_test.go
@@ -23,6 +23,9 @@ 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)
 	}