cmd/compile/internal/abt: use strings.Builder

Since go1.17 is now used for bootstrapping.

Change-Id: I5692ff4b38b7d9a279b20662ce5348ff34a2dde6
Reviewed-on: https://go-review.googlesource.com/c/go/+/427134
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: hopehook <hopehook@golangcn.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: David Chase <drchase@google.com>

diff --git a/src/cmd/compile/internal/abt/avlint32.go b/src/cmd/compile/internal/abt/avlint32.go
index 00bbccf45ae75085a1e5889b6eafba61eceb1a7d..eed5fa5d38b7b4ffc7a70e66858b36639084c21a 100644 (file)
--- a/src/cmd/compile/internal/abt/avlint32.go
+++ b/src/cmd/compile/internal/abt/avlint32.go
@@ -7,6 +7,7 @@ package abt
 import (
        "fmt"
        "strconv"
+       "strings"
 )
 
 const (
@@ -326,39 +327,21 @@ func (t *T) Equals(u *T) bool {
        return t.root.equals(u.root)
 }
 
-// This doesn't build with go1.4, sigh
-// func (t *T) String() string {
-//     var b strings.Builder
-//     first := true
-//     for it := t.Iterator(); !it.IsEmpty(); {
-//             k, v := it.Next()
-//             if first {
-//                     first = false
-//             } else {
-//                     b.WriteString("; ")
-//             }
-//             b.WriteString(strconv.FormatInt(int64(k), 10))
-//             b.WriteString(":")
-//             b.WriteString(v.String())
-//     }
-//     return b.String()
-// }
-
 func (t *T) String() string {
-       var b string
+       var b strings.Builder
        first := true
        for it := t.Iterator(); !it.Done(); {
                k, v := it.Next()
                if first {
                        first = false
                } else {
-                       b += ("; ")
+                       b.WriteString("; ")
                }
-               b += (strconv.FormatInt(int64(k), 10))
-               b += (":")
-               b += fmt.Sprint(v)
+               b.WriteString(strconv.FormatInt(int64(k), 10))
+               b.WriteString(":")
+               b.WriteString(fmt.Sprint(v))
        }
-       return b
+       return b.String()
 }
 
 func (t *node32) equals(u *node32) bool {