Improve multiple areas PRs with user friendly subs

This applies the same user friendly areas substitutions to the multiple
areas entries that it was already applied to single area entries.

As a bonus, add a case insensitive string sorting that avoids
exponential string allocation.

hack/tools/go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/spf13/pflag v1.0.5
 	github.com/valyala/fastjson v1.6.4
+	golang.org/x/exp v0.0.0-20230724220655-d98519c11495
 	golang.org/x/tools v0.9.3
 	google.golang.org/api v0.132.0
 	k8s.io/api v0.27.2
@@ -112,7 +113,7 @@ require (
 	github.com/subosito/gotenv v1.4.2 // indirect
 	go.opencensus.io v0.24.0 // indirect
 	golang.org/x/crypto v0.11.0 // indirect
-	golang.org/x/mod v0.10.0 // indirect
+	golang.org/x/mod v0.11.0 // indirect
 	golang.org/x/net v0.12.0 // indirect
 	golang.org/x/oauth2 v0.10.0 // indirect
 	golang.org/x/sys v0.10.0 // indirect

hack/tools/go.sum

@@ -519,6 +519,8 @@ golang.org/x/exp v0.0.0-20191227195350-da58074b4299/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
+golang.org/x/exp v0.0.0-20230724220655-d98519c11495 h1:zKGKw2WlGb8oPoRGqQ2PT8g2YoCN1w/YbbQjHXCdUWE=
+golang.org/x/exp v0.0.0-20230724220655-d98519c11495/go.mod h1:FXUEEKJgO7OQYeo8N01OfiKP8RXMtf6e8aTskBGqWdc=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -543,8 +545,8 @@ golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
-golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
-golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.11.0 h1:bUO06HqtnRcc/7l71XBe4WcqTZ+3AH1J59zWDDwLKgU=
+golang.org/x/mod v0.11.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181023162649-9b4f9f5ad519/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=

hack/tools/release/notes.go

@@ -29,10 +29,13 @@ import (
 	"os"
 	"os/exec"
 	"regexp"
-	"sort"
 	"strings"
 	"sync"
 	"time"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/exp/slices"
 )
 
 /*
@@ -175,6 +178,10 @@ func getAreaLabel(merge string) (string, error) {
 	var areaLabels []string
 	for _, label := range pr.Labels {
 		if area, ok := trimAreaLabel(label.Name); ok {
+			if userFriendlyArea, ok := userFriendlyAreas[area]; ok {
+				area = userFriendlyArea
+			}
+
 			areaLabels = append(areaLabels, area)
 		}
 	}
@@ -183,13 +190,9 @@ func getAreaLabel(merge string) (string, error) {
 	case 0:
 		return missingAreaLabelPrefix, nil
 	case 1:
-		area := areaLabels[0]
-		if userFriendlyArea, ok := userFriendlyAreas[area]; ok {
-			area = userFriendlyArea
-		}
-		return area, nil
+		return areaLabels[0], nil
 	default:
-		return multipleAreaLabelsPrefix + strings.Join(areaLabels, "|") + "]", nil
+		return multipleAreaLabelsPrefix + strings.Join(areaLabels, "/") + "]", nil
 	}
 }
 
@@ -366,11 +369,8 @@ func run() int {
 			}
 		default:
 			fmt.Println("## " + key)
-			sort.Slice(mergeslice, func(i int, j int) bool {
-				str1 := strings.ToLower(mergeslice[i])
-				str2 := strings.ToLower(mergeslice[j])
-				return str1 < str2
-			})
+			slices.SortFunc(mergeslice, lessStringCaseInsensitive)
+
 			for _, merge := range mergeslice {
 				fmt.Println(merge)
 			}
@@ -509,3 +509,42 @@ func generateReleaseNoteEntry(c *commit) (*releaseNoteEntry, error) {
 func trimReleaseBackportMarker(title string) string {
 	return releaseBackportMarker.ReplaceAllString(title, "${1}")
 }
+
+// lessStringCaseInsensitive implements the Less signature for strings with case insensitivity.
+// It can be used with the standard library sort utils.
+func lessStringCaseInsensitive(a, b string) bool {
+	for {
+		rb, sizeB := utf8.DecodeRuneInString(b)
+		if sizeB == 0 {
+			// Since b is of size 0, the number of runes
+			// in a is greater than or
+			// equal to the number of runes in b, hence
+			// a is not less than b.
+
+			return false
+		}
+
+		ra, sizeA := utf8.DecodeRuneInString(a)
+		if sizeA == 0 {
+			// Since b is not of size 0 and a's size is 0,
+			// the number of runes in b is greater than
+			// the number of runes in a, hence
+			// a is less than b.
+			return true
+		}
+
+		rb = unicode.ToLower(rb)
+		ra = unicode.ToLower(ra)
+
+		if ra != rb {
+			return ra < rb
+		}
+
+		// Trim the runes we just compared and continue.
+		// This loop will continue until we either find
+		// a pair of runes that are different or we consume
+		// all the runes on one of the strings.
+		a = a[sizeA:]
+		b = b[sizeB:]
+	}
+}