Implement parallel-letter-frequency

config.json

@@ -751,6 +751,15 @@
         "prerequisites": [],
         "difficulty": 1,
         "topics": []
+      },
+      {
+        "slug": "parallel-letter-frequency",
+        "name": "Parallel Letter Frequency",
+        "uuid": "e0e62b08-01d7-48a3-ae50-51f4a05ac003",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1,
+        "topics": []
       }
     ]
   },

exercises/practice/parallel-letter-frequency/.docs/instructions.md

@@ -0,0 +1,7 @@
+# Instructions
+
+Count the frequency of letters in texts using parallel computation.
+
+Parallelism is about doing things in parallel that can also be done sequentially.
+A common example is counting the frequency of letters.
+Create a function that returns the total frequency of each letter in a list of texts and that employs parallelism.

exercises/practice/parallel-letter-frequency/.meta/config.json

@@ -0,0 +1,15 @@
+{
+  "authors": [],
+  "files": {
+    "solution": [
+      "lib/ParallelLetterFrequency.rakumod"
+    ],
+    "test": [
+      "t/parallel-letter-frequency.rakutest"
+    ],
+    "example": [
+      ".meta/solutions/lib/ParallelLetterFrequency.rakumod"
+    ]
+  },
+  "blurb": "Count the frequency of letters in texts using parallel computation."
+}

exercises/practice/parallel-letter-frequency/.meta/solutions/lib/ParallelLetterFrequency.rakumod

@@ -0,0 +1,8 @@
+unit module ParallelLetterFrequency;
+
+sub letter-frequencies (+@texts) is export {
+    return @texts
+      .race( :batch(2) )
+      .map( *.lc.comb(/<:L>/).Slip )
+      .Bag;
+}

exercises/practice/parallel-letter-frequency/.meta/solutions/t/parallel-letter-frequency.rakutest

@@ -0,0 +1 @@
+../../../t/parallel-letter-frequency.rakutest

exercises/practice/parallel-letter-frequency/.meta/template-data.yaml

@@ -0,0 +1,25 @@
+properties:
+  calculateFrequencies:
+    test: |-
+      sprintf(q:to/END/, (%case<input><texts><>.List, %case<expected><>, %case<description>).map(*.raku));
+      cmp-ok(
+          letter-frequencies%s,
+          "(==)",
+          %s.Bag,
+          %s,
+      );
+      END
+
+unit: module
+
+example: |-
+  sub letter-frequencies (+@texts) is export {
+      return @texts
+        .race( :batch(2) )
+        .map( *.lc.comb(/<:L>/).Slip )
+        .Bag;
+  }
+
+stub: |-
+  sub letter-frequencies (+@texts) is export {
+  }

exercises/practice/parallel-letter-frequency/.meta/tests.toml

@@ -0,0 +1,49 @@
+# 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.
+
+[c054d642-c1fa-4234-8007-9339f2337886]
+description = "no texts"
+
+[818031be-49dc-4675-b2f9-c4047f638a2a]
+description = "one text with one letter"
+
+[c0b81d1b-940d-4cea-9f49-8445c69c17ae]
+description = "one text with multiple letters"
+
+[708ff1e0-f14a-43fd-adb5-e76750dcf108]
+description = "two texts with one letter"
+
+[1b5c28bb-4619-4c9d-8db9-a4bb9c3bdca0]
+description = "two texts with multiple letters"
+
+[6366e2b8-b84c-4334-a047-03a00a656d63]
+description = "ignore letter casing"
+
+[92ebcbb0-9181-4421-a784-f6f5aa79f75b]
+description = "ignore whitespace"
+
+[bc5f4203-00ce-4acc-a5fa-f7b865376fd9]
+description = "ignore punctuation"
+
+[68032b8b-346b-4389-a380-e397618f6831]
+description = "ignore numbers"
+
+[aa9f97ac-3961-4af1-88e7-6efed1bfddfd]
+description = "Unicode letters"
+
+[7b1da046-701b-41fc-813e-dcfb5ee51813]
+description = "combination of lower- and uppercase letters, punctuation and white space"
+
+[4727f020-df62-4dcf-99b2-a6e58319cb4f]
+description = "large texts"
+
+[adf8e57b-8e54-4483-b6b8-8b32c115884c]
+description = "many small texts"

exercises/practice/parallel-letter-frequency/lib/ParallelLetterFrequency.rakumod

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+unit module ParallelLetterFrequency;
+
+sub letter-frequencies (+@texts) is export {
+}