series

elixir/series/.exercism/config.json

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+{
+  "authors": [
+    "DoggettCK"
+  ],
+  "contributors": [
+    "amencarini",
+    "angelikatyborska",
+    "Cohen-Carlisle",
+    "devonestes",
+    "neenjaw",
+    "sotojuan"
+  ],
+  "files": {
+    "solution": [
+      "lib/string_series.ex"
+    ],
+    "test": [
+      "test/string_series_test.exs"
+    ],
+    "example": [
+      ".meta/example.ex"
+    ]
+  },
+  "blurb": "Given a string of digits, output all the contiguous substrings of length `n` in that string.",
+  "source": "A subset of the Problem 8 at Project Euler",
+  "source_url": "https://projecteuler.net/problem=8"
+}

elixir/series/.exercism/metadata.json

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+{"track":"elixir","exercise":"series","id":"17f1138f483f482b8bb2877fbfb0f91c","url":"https://exercism.org/tracks/elixir/exercises/series","handle":"negrienko","is_requester":true,"auto_approve":false}

elixir/series/.formatter.exs

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+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

elixir/series/.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+series-*.tar
+

elixir/series/HELP.md

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+# Help
+
+## Running the tests
+
+From the terminal, change to the base directory of the exercise then execute the tests with:
+
+```bash
+$ mix test
+```
+
+This will execute the test file found in the `test` subfolder -- a file ending in `_test.exs`
+
+Documentation:
+
+* [`mix test` - Elixir's test execution tool](https://hexdocs.pm/mix/Mix.Tasks.Test.html)
+* [`ExUnit` - Elixir's unit test library](https://hexdocs.pm/ex_unit/ExUnit.html)
+
+## Pending tests
+
+In test suites of practice exercises, all but the first test have been tagged to be 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:
+
+```elixir
+# @tag :pending
+test "shouting" do
+  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
+end
+```
+
+If you wish to run all tests at once, you can include all skipped test by using the `--include` flag on the `mix test` command:
+
+```bash
+$ mix test --include pending
+```
+
+Or, you can enable all the tests by commenting out the `ExUnit.configure` line in the file `test/test_helper.exs`.
+
+```elixir
+# ExUnit.configure(exclude: :pending, trace: true)
+```
+
+## Useful `mix test` options
+
+* `test/<FILE>.exs:LINENUM` - runs only a single test, the test from `<FILE>.exs` whose definition is on line `LINENUM`
+* `--failed` - runs only tests that failed the last time they ran
+* `--max-failures` - the suite stops evaluating tests when this number of test failures
+is reached
+* `--seed 0` - disables randomization so the tests in a single file will always be ran
+in the same order they were defined in
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit lib/string_series.ex` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Elixir track's documentation](https://exercism.org/docs/tracks/elixir)
+- The [Elixir track's programming category on the forum](https://forum.exercism.org/c/programming/elixir)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+If you're stuck on something, it may help to look at some of the [available resources](https://exercism.org/docs/tracks/elixir/resources) out there where answers might be found.

elixir/series/README.md

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+# Series
+
+Welcome to Series on Exercism's Elixir Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Given a string of digits, output all the contiguous substrings of length `n` in that string in the order that they appear.
+
+For example, the string "49142" has the following 3-digit series:
+
+- "491"
+- "914"
+- "142"
+
+And the following 4-digit series:
+
+- "4914"
+- "9142"
+
+And if you ask for a 6-digit series from a 5-digit string, you deserve whatever you get.
+
+Note that these series are only required to occupy _adjacent positions_ in the input;
+the digits need not be _numerically consecutive_.
+
+## Source
+
+### Created by
+
+- @DoggettCK
+
+### Contributed to by
+
+- @amencarini
+- @angelikatyborska
+- @Cohen-Carlisle
+- @devonestes
+- @neenjaw
+- @sotojuan
+
+### Based on
+
+A subset of the Problem 8 at Project Euler - https://projecteuler.net/problem=8

elixir/series/lib/string_series.ex

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+defmodule StringSeries do
+  @doc """
+  Given a string `s` and a positive integer `size`, return all substrings
+  of that size. If `size` is greater than the length of `s`, or less than 1,
+  return an empty list.
+  """
+  @spec slices(s :: String.t(), size :: integer) :: list(String.t())
+  def slices(s, size) do
+    length = String.length(s)
+    for start <- 0..(length - size), size in 1..length, into: [], do: String.slice(s, start, size)
+  end
+end

elixir/series/mix.exs

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+defmodule StringSeries.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :string_series,
+      version: "0.1.0",
+      # elixir: "~> 1.8",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      # {:dep_from_hexpm, "~> 0.3.0"},
+      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+    ]
+  end
+end

elixir/series/test/string_series_test.exs

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+defmodule StringSeriesTest do
+  use ExUnit.Case
+
+  test "slices of size 1 from one" do
+    assert StringSeries.slices("1", 1) == ["1"]
+  end
+
+  test "slices of size 1 from two" do
+    assert StringSeries.slices("12", 1) == ["1", "2"]
+  end
+
+  test "slices of size 1 from more" do
+    assert StringSeries.slices("01234", 1) == ["0", "1", "2", "3", "4"]
+  end
+
+  test "slices of size 2" do
+    assert StringSeries.slices("35", 2) == ["35"]
+  end
+
+  test "slices of size 2 overlap" do
+    assert StringSeries.slices("9142", 2) == ["91", "14", "42"]
+  end
+
+  test "slices of size 2 from more" do
+    assert StringSeries.slices("01234", 2) == ["01", "12", "23", "34"]
+  end
+
+  test "slices of size 3" do
+    assert StringSeries.slices("01234", 3) == ["012", "123", "234"]
+  end
+
+  test "slices of size 4" do
+    assert StringSeries.slices("01234", 4) == ["0123", "1234"]
+  end
+
+  test "slices include duplicates" do
+    assert StringSeries.slices("777777", 3) == ["777", "777", "777", "777"]
+  end
+
+  test "slices of a long series" do
+    assert StringSeries.slices("918493904243", 5) == [
+             "91849",
+             "18493",
+             "84939",
+             "49390",
+             "93904",
+             "39042",
+             "90424",
+             "04243"
+           ]
+  end
+
+  test "slices same size as string" do
+    assert StringSeries.slices("01234", 5) == ["01234"]
+  end
+
+  test "Unicode characters count as a single character" do
+    assert StringSeries.slices("José", 1) == ["J", "o", "s", "é"]
+    assert StringSeries.slices("José", 2) == ["Jo", "os", "sé"]
+  end
+
+  test "slices with size longer than string return empty list" do
+    assert StringSeries.slices("01234", 6) == []
+  end
+
+  test "slices with size zero or negative return empty list" do
+    assert StringSeries.slices("01234", -1) == []
+    assert StringSeries.slices("01234", 0) == []
+  end
+end

elixir/series/test/test_helper.exs

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+ExUnit.start()
+ExUnit.configure(exclude: :pending, trace: true)