I can do what I wanted with the new compiler.

    string filename = "data.txt";
    auto nums = pipe!(readText, split, map!(to!(uint)))(filename);

Like I write in my previous post. I think, Andrei has read it ^_^. It is even nicer than compose some times because order of application is left to right. This works to:

    string filename = "data.txt";
    auto nums = compose!(map!(to!(uint)), split, readText)(filename);

But is a bit hard to read because you read order right to left. It is good to have both functions.

There is a question. This does not work

    auto nums = pipe!(readText, split, map!(to!(uint)))("data.txt");

with odd Error: slice a[] is not mutable.

What could happen? The file name should not change. Thank you, Dee Girl