Add parallel-letter-frequency exercise (#170)

config.json

@@ -420,6 +420,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 3
+      },
+      {
+        "slug": "parallel-letter-frequency",
+        "name": "Parallel Letter Frequency",
+        "uuid": "8f55c666-41f7-42df-abf2-7133af0cb36a",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 6
       }
     ]
   },

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.
+Employ parallelism to calculate the total frequency of each letter in a list of texts.

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

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "erikschierboom"
+  ],
+  "files": {
+    "solution": [
+      "parallel-letter-frequency.8th"
+    ],
+    "test": [
+      "test.8th"
+    ],
+    "example": [
+      ".meta/example.8th"
+    ]
+  },
+  "blurb": "Count the frequency of letters in texts using parallel computation."
+}

exercises/practice/parallel-letter-frequency/.meta/example.8th

@@ -0,0 +1,21 @@
+needs array/parallel
+
+: increment-frequency \ m n -- m
+  0 m:!? swap ' n:1+ m:op!
+;
+
+: letters \ s -- a
+  /\p{L}/ r:/
+;
+
+: letter-frequencies \ s -- m
+  s:lc letters ( dup -rot increment-frequency ) {} const a:reduce
+;
+
+: merge-frequencies \ a -- m
+  ( ( >r dup -rot 0 m:@? r> n:+ rot swap m:! ) m:each drop ) {} const a:reduce
+;
+
+: >frequencies \ a -- m
+  a:len ' letter-frequencies swap a:map-par merge-frequencies
+;

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

@@ -0,0 +1,50 @@
+# 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"
+include = false
+
+[adf8e57b-8e54-4483-b6b8-8b32c115884c]
+description = "many small texts"

exercises/practice/parallel-letter-frequency/libs/exercism/test

@@ -0,0 +1,173 @@
+needs console/loaded
+
+\ -----------------------------------------------------------------
+
+ns: test
+
+-1 var, test-count
+var tests-passed
+var tests-failed
+var tests-skipped
+true var, run-test
+
+\ Some utility words
+
+
+: test-passed \ s x x --   \\ test name, expected value, actual value
+    2drop
+    1 tests-passed n:+!
+    con:green con:onBlack . space " ... OK" . con:white con:onBlack cr
+;
+
+: test-skipped \ s --
+    1 tests-skipped n:+!
+    con:cyan con:onBlack . space " ... SKIPPED" . con:white con:onBlack cr
+;
+
+: test-failed \ s x x --   \\ test name, expected value, actual value
+    1 tests-failed n:+!
+    rot
+    con:red con:onBlack . space " ... FAIL" . con:white con:onBlack cr
+    "    Actual:    «" . . "»" . cr
+    "    Expected:  «" . . "»" . cr cr
+;
+
+: isword?  \ x -- x f
+   dup  >kind  ns:w   n:= 
+;
+
+: run-test? \ -- T
+   run-test @ if true else "RUN_ALL_TESTS" getenv n:>bool then
+;
+
+\ Num passed + num skipped + num failed should == num tests
+: all-tests-run? \ -- T
+    tests-passed @ tests-skipped @ tests-failed @ n:+ n:+
+    test-count @ n:=
+;
+
+\ returns true if x is a date, false otherwise
+: date? \ x -- x T
+    dup >kind ns:d n:=
+;
+
+\ adapted from 8th forum -- https://8th-dev.com/forum/index.php/topic,2745.0.html
+: eq? \ x x -- T
+   \ are the items the same kind?
+   2dup >kind swap >kind n:=
+   !if 2drop false ;then
+
+   \ same kind: try different comparators
+   number? if n:= ;then
+   string? if s:= ;then
+   array?  if ' eq? a:= 2nip ;then
+   map?    if ' eq? m:= 2nip ;then
+   date?   if d:= ;then
+
+   \ otherwise fall back to 'lazy evaluation'
+   l: =
+;
+
+: eps_eq? \ n x x -- T
+   \ are the items the same kind?
+   2dup >kind swap >kind n:=
+   !if 2drop false ;then
+   number? !if 2drop false ;then  
+   rot n:~=
+;
+
+: check-depth \ ... n -- ...
+  dup>r
+  n:1+ depth n:=
+  !if
+    con:red con:onBlack 
+    "PANIC: expected stack depth to be " . r> . cr
+    "Stack is:" . cr
+    .s cr
+    255 die
+  then
+  rdrop
+;
+
+\ -----------------------------------------------------------------
+
+\ status report at end of run
+( all-tests-run?  
+  !if con:red con:onBlack "... FAIL - not all tests completed" . con:white con:onBlack cr then
+) onexit
+
+\ Print a summary of the tests run
+( con:white con:onBlack
+  test-count   @ . space "tests planned - " .
+  tests-passed @ . space "passed - " .
+  tests-skipped @ . space "skipped - " .
+  tests-failed @ . space "failed" . cr
+) onexit
+
+\ -----------------------------------------------------------------
+\ The public-facing words
+\ -----------------------------------------------------------------
+
+: equal? \ s x w -- | s w x --
+   run-test? !if 2drop test-skipped ;; then
+   isword? !if swap then
+   w:exec
+   3 check-depth
+   2dup             \ so test-failed can show actual and expected
+   eq? if test-passed else test-failed then
+;
+
+: approx_equal? \ s x w n -- | s w x n --
+   run-test? !if 3drop test-skipped ;; then
+   -rot isword? !if swap then
+   w:exec
+   4 check-depth
+   3dup            \ so test-failed can show actual and expected
+   eps_eq?
+   if rot drop test-passed else rot drop test-failed then
+;
+
+: true? \ s w --
+   run-test? !if drop test-skipped ;; then
+   w:exec
+   2 check-depth
+   true swap dup    \ so test-failed can show actual and expected
+   if test-passed else test-failed then 
+;
+
+: false? \ s w --
+   run-test? !if drop test-skipped ;; then
+   w:exec
+   2 check-depth
+   false swap dup    \ so test-failed can show actual and expected
+   !if test-passed else test-failed then 
+;
+
+: null? \ s w --
+   run-test? !if drop test-skipped ;; then
+   w:exec
+   2 check-depth
+   null swap dup     \ so test-failed can show actual and expected
+   G:null? nip if test-passed else test-failed then 
+;
+
+: SKIP-REST-OF-TESTS false run-test ! ;
+
+: tests \ n -- 
+    test-count ! 
+;
+
+\ Set the exit status:
+\   0 = all OK
+\   1 = not all tests were run (some error occurred)
+\   2 = some tests failed
+: end-of-tests \ --
+    all-tests-run?
+    if
+      tests-failed @ 0 n:= if 0 else 2 then
+    else
+      1
+    then
+    die
+;
+

exercises/practice/parallel-letter-frequency/parallel-letter-frequency.8th

@@ -0,0 +1,3 @@
+: >frequencies \ a -- m
+
+;

exercises/practice/parallel-letter-frequency/test.8th

@@ -0,0 +1,70 @@
+"parallel-letter-frequency.8th" f:include
+needs exercism/test
+with: test
+12 tests
+
+"no texts"
+    ( [] >frequencies )
+    {}
+    equal?
+
+SKIP-REST-OF-TESTS
+
+"one text with one letter"
+    ( ["a"] >frequencies )
+    {"a": 1}
+    equal?
+
+"one text with multiple letters"
+    ( ["bbcccd"] >frequencies )
+    {"b": 2, "c": 3, "d": 1}
+    equal?
+
+"two texts with one letter"
+    ( ["e", "f"] >frequencies )
+    {"e": 1, "f": 1}
+    equal?
+
+"two texts with multiple letters"
+    ( ["ggh", "hhi"] >frequencies )
+    {"g": 2, "h": 3, "i": 1}
+    equal?
+
+"ignore letter casing"
+    ( ["m", "M"] >frequencies )
+    {"m": 2}
+    equal?
+
+"ignore whitespace"
+    ( ["   ", "	", "
+"] >frequencies )
+    {}
+    equal?
+
+"ignore punctuation"
+    ( ["!", "?", ";", ",", "."] >frequencies )
+    {}
+    equal?
+
+"ignore numbers"
+    ( ["1", "2", "3", "4", "5", "6", "7", "8", "9"] >frequencies )
+    {}
+    equal?
+
+"Unicode letters"
+    ( ["本", "φ", "ほ", "ø"] >frequencies )
+    {"本": 1, "φ": 1, "ほ": 1, "ø": 1}
+    equal?
+
+"combination of lower- and uppercase letters, punctuation and white space"
+    ( ["There, peeping among the cloud-wrack above a dark tower high up in the mountains, Sam saw a white star twinkle for a while. The beauty of it smote his heart, as he looked up out of the forsaken land, and hope returned to him. For like a shaft, clear and cold, the thought pierced him that in the end, the shadow was only a small and passing thing: there was light and high beauty forever beyond its reach."] >frequencies )
+    {"a": 32, "b": 4, "c": 6, "d": 14, "e": 37, "f": 7, "g": 8, "h": 29, "i": 19, "k": 6, "l": 12, "m": 7, "n": 19, "o": 22, "p": 7, "r": 17, "s": 16, "t": 30, "u": 9, "v": 2, "w": 9, "y": 4}
+    equal?
+
+"many small texts"
+    ( ["abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc", "abbccc"] >frequencies )
+    {"a": 50, "b": 100, "c": 150}
+    equal?
+
+end-of-tests
+;with