Added custom printers

repl/typeprinter.go

@@ -0,0 +1,20 @@
+package repl
+
+import (
+	"fmt"
+	"io"
+	"reflect"
+)
+
+func AddTypePrinter[T any](r *REPL, p func(w io.Writer, t T, concise bool) error) {
+	var t T
+
+	tt := reflect.TypeOf(t)
+	r.typePrinters[tt] = func(w io.Writer, v any, concise bool) error {
+		vt, ok := v.(T)
+		if !ok {
+			return fmt.Errorf("cannot convert %v to T", v)
+		}
+		return p(w, vt, concise)
+	}
+}