It seems that with Ryan&#39;s approach, DList is not needed, simple concat works fine.<div><br></div><div>It also seems to run in constant space. Now I must do the exercise of rewriting it to see why concat works, since &gt;&gt;= is infixl and ++ is infixr, this seems odd :) But again, my mind might be thinking too strict (bad imperative habits?)</div>
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