README.md

Computational graph interface with type conversion

20 lines of source lines of code to make your life easier with complex computations and transformations.

Declarative style. Type safe.

Example

The drawing visualizes a computational graph with single output node as a supplier of String result. The inputs are suppliers of variables of different types.

Here is how to declare the above computational graph.

Random random = new Random();
Node<Integer> nodeA = Nodes.node(random::nextDouble)
        .transform(aDouble -> 100. * aDouble)
        .transform(d -> (int) Math.round(d));
Node<Integer> nodeB = Nodes.node(() -> random.ints(10, 100, 1000))
        .transform(IntStream::sum)
        .transform(integer -> integer % 100);
Node<Double> nodeC = Nodes.node(random::nextDouble)
        .compose(random::nextDouble, (aDouble, aDouble2) -> aDouble - aDouble2);
Node<Integer> nodeD = nodeC.transform(Math::tan).transform(aDouble -> 100. * aDouble ).transform(Double::intValue);
Node<Integer> nodeE = nodeA
        .compose(nodeB, (integer, integer2) -> integer * integer2)
        .compose(nodeD, (integer, integer2) -> integer * integer2);
Node<String> nodeF = nodeE.transform(String::valueOf);
Node<String> nodeG = Nodes.node(() -> "Result: ")
                .compose(nodeF, String::concat);

Which can be refactored to pure supplier of a result as follows.

Supplier<String> result = Nodes.node(() -> "Result: ")
        .compose(Nodes.node(random::nextDouble)
                .transform(aDouble -> 100. * aDouble)
                .transform(d -> (int) Math.round(d))
                .compose(Nodes.node(() -> random.ints(10, 100, 1000))
                        .transform(IntStream::sum)
                        .transform(integer1 -> integer1 % 100), (integer, integer2) -> integer * integer2)
                .compose(Nodes.node(random::nextDouble)
                        .compose(random::nextDouble, (aDouble1, aDouble2) -> aDouble1 - aDouble2)
                        .transform(Math::tan)
                        .transform(aDouble1 -> 100. * aDouble1)
                        .transform(Double::intValue), (integer, integer2) -> integer * integer2)
                .transform(String::valueOf), String::concat);

Then just get a result.

IntStream.range(0, 100).forEach(i -> System.out.println(result.get()));

Project goal and state

Just for fun, but useful. To be improved...