Write a Domain Specific Language similar to the Graphviz dot language.

A Domain Specific Language (DSL) is a small language optimized for a specific domain.

For example the DOT language allows you to write a textual description of a graph which is then transformed into a picture by one of the Graphviz tools (such as dot). A simple graph looks like this:

graph {
    graph [bgcolor="yellow"]
    a [color="red"]
    b [color="blue"]
    a -- b [color="green"]
}

Putting this in a file example.dot and running dot example.dot -T png -o example.png creates an image example.png with red and blue circle connected by a green line on a yellow background.

Create a DSL similar to the dot language.

Execute the tests with:

$ mix test

In the test suites, all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by commenting out the relevant @tag :pending with a # symbol.

For example:

# @tag :pending
test "shouting" do
  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end

Or, you can enable all the tests by commenting out the ExUnit.configure line in the test suite.

# ExUnit.configure exclude: :pending, trace: true

If you're stuck on something, it may help to look at some of the available resources out there where answers might be found.

It's possible to submit an incomplete solution so you can see how others have completed the exercise.