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kmarker1101fapdashBNAndras
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Parallel letter frequency (exercism#422)
* add parallel-letter-frequency, part of 48 in 24 * practice-exercise-generator: Don't include commas in test names (exercism#420) fixes exercism#419 * fix merge conflict * fix json formating issue * fix merge issue * refactor to use parallism * check if ci failure was a fluke * fix ci failure * add empty string check * return hash-table, update difficulty * cleanup, fix error * add instructions.append * Use extra file for subprocess code * bin/test-examples: Handle testing of exercises with additional files * Don't use additional solution file * add BNAndras and fapdash as contributors * Use printed representation for hash table (de)serialization * Revert changes to `bin/test-examples` See exercism#422 (comment) * refactor tests * Typo fix --------- Co-authored-by: FAP <[email protected]> Co-authored-by: András B Nagy <[email protected]>
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‎config.json

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"practices": [],
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"prerequisites": [],
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"difficulty": 5
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},
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{
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"slug": "parallel-letter-frequency",
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"name": "Parallel Letter Frequency",
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"uuid": "3daf3903-1eb0-49b9-827a-76e6b7ca25fb",
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"practices": [],
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"prerequisites": [],
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"difficulty": 10
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}
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]
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},

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

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# Instructions append
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## Using Parallelism
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The goal of this exercise is to practice parallelism with Emacs Lisp.
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In Emacs Lisp this can be achieved by using [`asynchronous processes`](https://www.gnu.org/software/emacs/manual/html_node/elisp/Asynchronous-Processes.html#:~:text=An%20asynchronous%20process%20is%20controlled,%2Dtype%20(see%20below)).
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You may also want to look at the documentation for [`batch mode`](https://www.gnu.org/software/emacs/manual/html_node/elisp/Batch-Mode.html), [`sentinels`](https://www.gnu.org/software/emacs/manual/html_node/elisp/Sentinels.html) and [`receiving output from processes`](https://www.gnu.org/software/emacs/manual/html_node/elisp/Output-from-Processes.html).

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

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# Instructions
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Count the frequency of letters in texts using parallel computation.
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Parallelism is about doing things in parallel that can also be done sequentially.
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A common example is counting the frequency of letters.
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Employ parallelism to calculate the total frequency of each letter in a list of texts.

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

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{
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"authors": [
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"kmarker1101"
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],
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"contributors": [
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"fapdash",
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"BNAndras"
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],
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"files": {
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"solution": [
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"parallel-letter-frequency.el"
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],
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"test": [
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"parallel-letter-frequency-test.el"
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],
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"example": [
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".meta/example.el"
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]
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},
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"blurb": "Count the frequency of letters in texts using parallel computation."
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}

‎exercises/practice/parallel-letter-frequency/.meta/example.el

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;;; parallel-letter-frequency.el --- Parallel Letter Frequency (exercism) -*- lexical-binding: t; -*-
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;;; Commentary:
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;;; Code:
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(require 'cl-lib)
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(defun clean-text (text)
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(downcase (replace-regexp-in-string "[^[:alpha:]]" "" text)))
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(defun combine-frequencies (freqs-list)
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(let ((combined-freqs (make-hash-table :test 'equal)))
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(dolist (freqs freqs-list)
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(maphash (lambda (key value)
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(puthash key (+ value (gethash key combined-freqs 0)) combined-freqs))
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freqs))
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combined-freqs))
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(defun calculate-frequencies (texts)
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(let ((cleaned-texts (mapcar #'clean-text texts)))
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(if (cl-every #'string-empty-p cleaned-texts)
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(make-hash-table :test 'equal)
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(let* ((num-processes (min (length cleaned-texts) (max 1 (string-to-number (shell-command-to-string "nproc")))))
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(texts-per-process (ceiling (/ (float (length cleaned-texts)) num-processes)))
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(results (make-hash-table :test 'equal))
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(pending num-processes)
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(final-result (make-hash-table :test 'equal))
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(processes nil))
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(dotimes (i num-processes)
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(let* ((start-index (* i texts-per-process))
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(end-index (min (* (1+ i) texts-per-process) (length cleaned-texts)))
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(process-texts (if (< start-index (length cleaned-texts))
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(cl-subseq cleaned-texts start-index end-index)
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'())))
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(when (not (null process-texts))
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(let* ((command (prin1-to-string `(calculate-frequencies-in-subprocess ',process-texts)))
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(process (make-process
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:name (format "letter-freq-process-%d" i)
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:buffer (generate-new-buffer (format " *letter-freq-process-%d*" i))
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:command (list "emacs" "--batch" "-l" "parallel-letter-frequency.el" "--eval" command)
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:sentinel (lambda (proc _event)
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(when (eq (process-status proc) 'exit)
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(with-current-buffer (process-buffer proc)
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(let ((result (read (buffer-string))))
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(maphash (lambda (key value)
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(puthash key (+ value (gethash key results 0)) results))
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result))
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(setq pending (1- pending))
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(when (= pending 0)
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(setq final-result (combine-frequencies (list results))))))))))
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(push process processes)))))
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(while (> pending 0)
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(sleep-for 0.1))
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final-result))))
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(defun calculate-frequencies-in-subprocess (texts)
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(let ((freqs (make-hash-table :test 'equal)))
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(dolist (text texts)
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(let ((text-freqs (make-hash-table :test 'equal)))
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(dolist (char (string-to-list text))
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(when (string-match-p "[[:alpha:]]" (char-to-string char))
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(puthash
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char (1+ (gethash char text-freqs 0)) text-freqs)))
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(maphash
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(lambda (key value)
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(puthash key (+ value (gethash key freqs 0)) freqs))
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text-freqs)))
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(prin1 freqs)))
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(provide 'parallel-letter-frequency)
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;;; parallel-letter-frequency.el ends here

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

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# This is an auto-generated file.
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#
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# Regenerating this file via `configlet sync` will:
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# - Recreate every `description` key/value pair
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# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
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# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
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# - Preserve any other key/value pair
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#
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# As user-added comments (using the # character) will be removed when this file
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# is regenerated, comments can be added via a `comment` key.
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[c054d642-c1fa-4234-8007-9339f2337886]
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description = "no texts"
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[818031be-49dc-4675-b2f9-c4047f638a2a]
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description = "one text with one letter"
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[c0b81d1b-940d-4cea-9f49-8445c69c17ae]
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description = "one text with multiple letters"
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[708ff1e0-f14a-43fd-adb5-e76750dcf108]
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description = "two texts with one letter"
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[1b5c28bb-4619-4c9d-8db9-a4bb9c3bdca0]
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description = "two texts with multiple letters"
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[6366e2b8-b84c-4334-a047-03a00a656d63]
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description = "ignore letter casing"
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[92ebcbb0-9181-4421-a784-f6f5aa79f75b]
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description = "ignore whitespace"
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[bc5f4203-00ce-4acc-a5fa-f7b865376fd9]
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description = "ignore punctuation"
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[68032b8b-346b-4389-a380-e397618f6831]
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description = "ignore numbers"
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[aa9f97ac-3961-4af1-88e7-6efed1bfddfd]
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description = "Unicode letters"
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[7b1da046-701b-41fc-813e-dcfb5ee51813]
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description = "combination of lower- and uppercase letters, punctuation and white space"
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[4727f020-df62-4dcf-99b2-a6e58319cb4f]
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description = "large texts"
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[adf8e57b-8e54-4483-b6b8-8b32c115884c]
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description = "many small texts"

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