Add series exercise (#85)

config.json

@@ -159,6 +159,14 @@
         "prerequisites": [],
         "difficulty": 2
       },
+      {
+        "slug": "series",
+        "name": "Series",
+        "uuid": "fac9c337-2216-414d-a7be-50205d161f3f",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "sublist",
         "name": "Sublist",

exercises/practice/series/.docs/instructions.md

@@ -0,0 +1,19 @@
+# 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_.

exercises/practice/series/.meta/Example.roc

@@ -0,0 +1,18 @@
+module [slices]
+
+slices : Str, U64 -> List Str
+slices = \string, sliceLength ->
+    chars = string |> Str.toUtf8
+    len = chars |> List.len
+    if len == 0 || sliceLength == 0 || sliceLength > len then
+        []
+    else
+        maybeList =
+            List.range { start: At 0, end: At (len - sliceLength) }
+            |> List.mapTry \startIndex ->
+                chars
+                |> List.sublist { start: startIndex, len: sliceLength }
+                |> Str.fromUtf8
+        when maybeList is
+            Ok list -> list
+            Err (BadUtf8 _ _) -> crash "Only ASCII strings are supported"

exercises/practice/series/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "ageron"
+  ],
+  "files": {
+    "solution": [
+      "Series.roc"
+    ],
+    "test": [
+      "series-test.roc"
+    ],
+    "example": [
+      ".meta/Example.roc"
+    ]
+  },
+  "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"
+}

exercises/practice/series/.meta/template.j2

@@ -0,0 +1,18 @@
+{%- import "generator_macros.j2" as macros with context -%}
+{{ macros.canonical_ref() }}
+{{ macros.header() }}
+
+import {{ exercise | to_pascal }} exposing [{{ cases[0]["property"] | to_camel }}]
+
+{% for case in cases -%}
+# {{ case["description"] }}
+{%- if case["expected"]["error"] %} – just return an empty list{%- endif %}
+expect
+    result = {{ case["input"]["series"] | to_roc }} |> {{ case["property"] | to_camel }} {{ case["input"]["sliceLength"] | to_roc }}
+    {%- if case["expected"]["error"] %}
+    result == []
+    {%- else %}
+    result == {{ case["expected"] | to_roc }}
+    {%- endif %}
+
+{% endfor %}

exercises/practice/series/.meta/tests.toml

@@ -0,0 +1,44 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[7ae7a46a-d992-4c2a-9c15-a112d125ebad]
+description = "slices of one from one"
+
+[3143b71d-f6a5-4221-aeae-619f906244d2]
+description = "slices of one from two"
+
+[dbb68ff5-76c5-4ccd-895a-93dbec6d5805]
+description = "slices of two"
+
+[19bbea47-c987-4e11-a7d1-e103442adf86]
+description = "slices of two overlap"
+
+[8e17148d-ba0a-4007-a07f-d7f87015d84c]
+description = "slices can include duplicates"
+
+[bd5b085e-f612-4f81-97a8-6314258278b0]
+description = "slices of a long series"
+
+[6d235d85-46cf-4fae-9955-14b6efef27cd]
+description = "slice length is too large"
+
+[d7957455-346d-4e47-8e4b-87ed1564c6d7]
+description = "slice length is way too large"
+
+[d34004ad-8765-4c09-8ba1-ada8ce776806]
+description = "slice length cannot be zero"
+
+[10ab822d-8410-470a-a85d-23fbeb549e54]
+description = "slice length cannot be negative"
+include = false
+
+[c7ed0812-0e4b-4bf3-99c4-28cbbfc246a2]
+description = "empty series is invalid"

exercises/practice/series/Series.roc

@@ -0,0 +1,5 @@
+module [slices]
+
+slices : Str, U64 -> List Str
+slices = \string, sliceLength ->
+    crash "Please implement the 'slices' function"

exercises/practice/series/series-test.roc

@@ -0,0 +1,62 @@
+# These tests are auto-generated with test data from:
+# https://github.com/exercism/problem-specifications/tree/main/exercises/series/canonical-data.json
+# File last updated on 2024-09-13
+app [main] {
+    pf: platform "https://github.com/roc-lang/basic-cli/releases/download/0.15.0/SlwdbJ-3GR7uBWQo6zlmYWNYOxnvo8r6YABXD-45UOw.tar.br",
+}
+
+main =
+    Task.ok {}
+
+import Series exposing [slices]
+
+# slices of one from one
+expect
+    result = "1" |> slices 1
+    result == ["1"]
+
+# slices of one from two
+expect
+    result = "12" |> slices 1
+    result == ["1", "2"]
+
+# slices of two
+expect
+    result = "35" |> slices 2
+    result == ["35"]
+
+# slices of two overlap
+expect
+    result = "9142" |> slices 2
+    result == ["91", "14", "42"]
+
+# slices can include duplicates
+expect
+    result = "777777" |> slices 3
+    result == ["777", "777", "777", "777"]
+
+# slices of a long series
+expect
+    result = "918493904243" |> slices 5
+    result == ["91849", "18493", "84939", "49390", "93904", "39042", "90424", "04243"]
+
+# slice length is too large – just return an empty list
+expect
+    result = "12345" |> slices 6
+    result == []
+
+# slice length is way too large – just return an empty list
+expect
+    result = "12345" |> slices 42
+    result == []
+
+# slice length cannot be zero – just return an empty list
+expect
+    result = "12345" |> slices 0
+    result == []
+
+# empty series is invalid – just return an empty list
+expect
+    result = "" |> slices 1
+    result == []
+