use genericized slice-reversing function

irc/history/history.go

 package history
 
 import (
-	"github.com/ergochat/ergo/irc/utils"
 	"sync"
 	"time"
+
+	"github.com/ergochat/ergo/irc/utils"
 )
 
 type ItemType uint
 
 type Predicate func(item *Item) (matches bool)
 
-func Reverse(results []Item) {
-	for i, j := 0, len(results)-1; i < j; i, j = i+1, j-1 {
-		results[i], results[j] = results[j], results[i]
-	}
-}
-
 // Buffer is a ring buffer holding message/event history for a channel or user
 type Buffer struct {
 	sync.RWMutex
 
 	defer func() {
 		if !ascending {
-			Reverse(results)
+			utils.ReverseSlice(results)
 		}
 	}()
 

irc/mysql/history.go

 
 	results, err = mysql.selectItems(ctx, queryBuf.String(), args...)
 	if err == nil && !ascending {
-		history.Reverse(results)
+		utils.ReverseSlice(results)
 	}
 	return
 }

irc/utils/types.go

 	}
 	return
 }
+
+// reverse the order of a slice in place
+func ReverseSlice[T any](results []T) {
+	for i, j := 0, len(results)-1; i < j; i, j = i+1, j-1 {
+		results[i], results[j] = results[j], results[i]
+	}
+}