Add practice exercise piecing-it-together

[jiegillet]

Fun little exercise! Great use of the quadratic formula 💯

The idea is to fill in partial information about a jigsaw puzzle.
There are tons of ways information might be missing or contradictory, but I mostly stuck to the test cases.

[github-actions]

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[angelikatyborska]

Woohoo, more exercises 🙂

[angelikatyborska]

You have also used: enum, keyword-lists, maps, erlang-libraries. Which ones are really necessary for this exercise?

I'm assuming erlang-libraries are optional because Integer/Float.pow can be used instead of :math.sqrt. Is it common knowledge that pow(x, 0.5) == sqrt(x)?

As for enum, maps, and keyword-lists, they all come from the fact that you've turned then input struct into a keyword list. Was that really necessary? Can the exercise be solved without that?

    |> Map.from_struct()
    |> Enum.filter(fn {_, value} -> value end)
    |> Enum.sort_by(fn {key, _} -> key end)

[jiegillet]

I'm sure people know that pow(x, 0.5) == sqrt(x, but :math.sqrt is so much more natural, I didn't think twice before using it.

I'll add all of your suggestions, it's not really about whether they are all necessary (I'm sure you could write solutions that don't use them all), it's more about whether knowing about all these concepts can help you write a nice solution, and I think this is the case.

[angelikatyborska]

but I mostly stuck to the test cases.

Did you "mostly" stuck to the test cases, or "fully" stuck to the test cases? I was trying to find anything in the tests that doesn't come from problem specs but couldn't 🤔

[jiegillet]

Did you "mostly" stuck to the test cases, or "fully" stuck to the test cases? I was trying to find anything in the tests that doesn't come from problem specs but couldn't 🤔

The tests are strictly identical to the problem specs.

What I meant is that there is one test that expects {:error, "Contradictory data"} and one that expects {:error, "Insufficient data"}, implying that the solution should check for insufficient and contradictory data. However, there are many, many ways in which that could happen, and my example solution doesn't handle all of them.
My solution handles the invalid inputs from the tests, of course, and a couple that felt natural, for example when I have a clause pattern matching on format: :square, I feel that I should mention that other formats cannot be solved, even though that is technically dead code since it's not tested.

[angelikatyborska]

Looks great 🙂