Add series exercise (exercism#209)

config.json

@@ -631,6 +631,14 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "series",
+        "name": "Series",
+        "uuid": "a0477a3c-547e-4cde-a23e-a917fa408284",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "etl",
         "name": "ETL",

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/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "series.v"
+    ],
+    "test": [
+      "run_test.v"
+    ],
+    "example": [
+      ".meta/example.v"
+    ]
+  },
+  "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/example.v

@@ -0,0 +1,21 @@
+module main
+
+fn slices(series string, slice_length int) ![]string {
+	if series.len == 0 {
+		return error('series cannot be empty')
+	}
+	if slice_length > series.len {
+		return error('slice length cannot be greater than series length')
+	}
+	if slice_length == 0 {
+		return error('slice length cannot be zero')
+	}
+	if slice_length < 0 {
+		return error('slice length cannot be negative')
+	}
+	mut result := []string{}
+	for i in 0 .. (series.len - slice_length + 1) {
+		result << series[i..(i + slice_length)]
+	}
+	return result
+}

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

@@ -0,0 +1,36 @@
+# This is an auto-generated file. Regular comments will be removed when this
+# file is regenerated. Regenerating will not touch any manually added keys,
+# so comments can be added in 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"
+
+[c7ed0812-0e4b-4bf3-99c4-28cbbfc246a2]
+description = "empty series is invalid"

exercises/practice/series/run_test.v

@@ -0,0 +1,71 @@
+module main
+
+fn test_slices_of_one_from_one() {
+	expected := ['1']
+	assert slices('1', 1)! == expected
+}
+
+fn test_slices_of_one_from_two() {
+	expected := ['1', '2']
+	assert slices('12', 1)! == expected
+}
+
+fn test_slices_of_two() {
+	expected := ['35']
+	assert slices('35', 2)! == expected
+}
+
+fn test_slices_of_two_overlap() {
+	expected := ['91', '14', '42']
+	assert slices('9142', 2)! == expected
+}
+
+fn test_slices_can_include_duplicates() {
+	expected := ['777', '777', '777', '777']
+	assert slices('777777', 3)! == expected
+}
+
+fn test_slices_of_a_long_series() {
+	expected := ['91849', '18493', '84939', '49390', '93904', '39042', '90424', '04243']
+	assert slices('918493904243', 5)! == expected
+}
+
+fn test_slice_length_is_too_large() {
+	if res := slices('12345', 6) {
+		assert false, 'slice length too large should return an error'
+	} else {
+		assert err.msg() == 'slice length cannot be greater than series length'
+	}
+}
+
+fn test_slice_length_is_way_too_large() {
+	if res := slices('12345', 42) {
+		assert false, 'slice length way too large should return an error'
+	} else {
+		assert err.msg() == 'slice length cannot be greater than series length'
+	}
+}
+
+fn test_slice_length_cannot_be_zero() {
+	if res := slices('12345', 0) {
+		assert false, 'slice length cannot be zero should return an error'
+	} else {
+		assert err.msg() == 'slice length cannot be zero'
+	}
+}
+
+fn test_slice_length_cannot_be_negative() {
+	if res := slices('123', -1) {
+		assert false, 'slice length cannot be negative should return an error'
+	} else {
+		assert err.msg() == 'slice length cannot be negative'
+	}
+}
+
+fn test_empty_series_is_invalid() {
+	if res := slices('', 1) {
+		assert false, 'empty series invalid should return an error'
+	} else {
+		assert err.msg() == 'series cannot be empty'
+	}
+}

exercises/practice/series/series.v

@@ -0,0 +1,4 @@
+module main
+
+fn slices(series string, slice_length int) ![]string {
+}