Hi, trying wxHaskell GUI interface, i would like to get a list of all widgets in a frame. My frame is composed of 4 widgets and a panel containing 2 widgets. wlf <- get frame children gives a list of 5 widgets (4 + 1 panel) wlp <- get panel children gives a list of 2 widgets Making wlf ++ wlp gives the whole list of widgets in the frame. But, for a more general use, i want to explore recursively the hierarchy from frame, without having to explicitly know wether the frame contains other containers ... Since the <- syntax to get a list of children, i can't figure out how to write the recursive function to get all children of a frame. I can't write (x <- get widget children) ++ f (rest of list of widgets) , as for usual functions using lists. Thanks for helping. Didier.