Streaming API

Some streaming tricks for routine tasks:

Reading a file line by line and flatting words out to an array

    String[] words = reader
        .lines()
        .map(l -> l.split("\\s+"))
        .flatMap(Arrays::stream)
        .map(w -> w.replaceAll("[^a-zA-Z]",""))
        .map(String::toLowerCase)
        .filter(w -> !w.isEmpty())
        .toArray(String[]::new);

Reading a line and turning it to numbers

    int[] numbers = Arrays.stream(reader.readLine().split("\\s+"))
                     .mapToInt(Integer::parseInt)
                     .toArray();