feat(model): add item pre/post modelize hook

chat/batch.go

@@ -22,9 +22,16 @@ func (l *Log[T]) newbatch(sz int) *batch[T] {
 
 func (cl *batch[T]) String() string {
 	sb := strings.Builder{}
-	for _, item := range cl.items {
+	for i := range cl.items {
+		pre, post := cl.lst.preM, cl.lst.postM
+		if pre != nil {
+			pre(&cl.items[i])
+		}
 		sb.WriteString(cl.lst.itemsep)
-		sb.WriteString(item.String())
+		sb.WriteString(cl.items[i].String())
+		if post != nil {
+			post(&cl.items[i])
+		}
 	}
 	return sb.String()[len(cl.lst.itemsep):]
 }

chat/chat.go

@@ -14,6 +14,7 @@ type Log[T fmt.Stringer] struct {
 	itemsep            string
 	defaultprompt      string
 	m                  map[int64][]*batch[T]
+	preM, postM        func(*T)
 }
 
 func NewLog[T fmt.Stringer](batchcap, itemscap int, itemsep, defaultprompt string) Log[T] {
@@ -35,6 +36,18 @@ func NewLog[T fmt.Stringer](batchcap, itemscap int, itemsep, defaultprompt strin
 	}
 }
 
+// SetPreModelize will be called before calling item.String()
+func (l *Log[T]) SetPreModelize(fn func(*T)) *Log[T] {
+	l.preM = fn
+	return l
+}
+
+// SetPreModelize will be called after calling item.String()
+func (l *Log[T]) SetPostModelize(fn func(*T)) *Log[T] {
+	l.postM = fn
+	return l
+}
+
 func (l *Log[T]) Add(grp int64, item T, isbot bool) {
 	l.mu.Lock()
 	defer l.mu.Unlock()