diff options
| author |  Daphne Preston-Kendal
| 2022-11-26 13:00:05 +0100 |
|---|---|---|
| committer | Daphne Preston-Kendal
| 2022-11-26 13:00:05 +0100 |
| commit | c25e65bae96d6d5c26b0d9e8af96e8dcdbdaf99f (patch) | |
| tree | c267d5839f1e3b77d8c903952dd573ffeae1cb31 | |
| parent | Specify base cases and behaviours of each comparator function (diff) | |
| parent | Publish third draft. (diff) | |
Merge branch 'master' of https://github.com/scheme-requests-for-implementation/srfi-228
Diffstat (limited to '')
| -rw-r--r-- | README.org | 8 | ||||
| -rw-r--r-- | index.html | 107 | ||||
| -rw-r--r-- | srfi-228-test.scm | 83 | ||||
| -rw-r--r-- | srfi-228.html | 7 | ||||
| -rw-r--r-- | srfi/228.sld | 7 | ||||
| -rw-r--r-- | srfi/srfi-228.scm (renamed from srfi/composing-comparators.scm) | 3 |
6 files changed, 126 insertions, 89 deletions
@@ -1,4 +1,5 @@ -* SRFI 228: A further comparator library + +* SRFI 228: Composing Comparators ** by Daphne Preston-Kendal @@ -6,15 +7,14 @@ keywords: [[https://srfi.schemers.org/?keywords=comparison][Comparison]] -This repository hosts [[https://srfi.schemers.org/srfi-228/][SRFI 228]]: A further comparator library, a [[https://srfi.schemers.org/][Scheme Request for Implementation]]. +This repository hosts [[https://srfi.schemers.org/srfi-228/][SRFI 228]]: Composing Comparators, a [[https://srfi.schemers.org/][Scheme Request for Implementation]]. This SRFI is in /draft/ status. - +See also [[/srfi-128/][SRFI 128: Comparators (reduced)]] and [[/srfi-162/][SRFI 162: Comparators sublibrary]]. The full documentation for this SRFI can be found in the [[https://srfi.schemers.org/srfi-228/srfi-228.html][SRFI Document]]. If you'd like to participate in the discussion of this SRFI, or report issues with it, please [[https://srfi.schemers.org/srfi-228/][join the SRFI-228 mailing list]] and send your message there. Thank you. - [[mailto:srfi-editors@srfi.schemers.org][The SRFI Editors]] @@ -1,81 +1,32 @@ <!DOCTYPE html> <html> - <head> - <title>A further comparator library</title> - <link href="/admin.css" rel="stylesheet"> - <link href="/list.css" rel="stylesheet"> - <link href="/favicon.png" rel="icon" sizes="192x192" type="image/png"> - <meta charset="utf-8" /> - <meta name="viewport" content="width=device-width, initial-scale=1" /> - <script type="text/x-mathjax-config"> - MathJax.Hub.Config({ - tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']]} - }); - </script> - <script crossorigin="anonymous" integrity= - "sha384-Ra6zh6uYMmH5ydwCqqMoykyf1T/+ZcnOQfFPhDrp2kI4OIxadnhsvvA2vv9A7xYv" src= - "https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML" - type="text/javascript"></script> - </head> + <head> + <title>Composing Comparators</title> + <link href="/admin.css" rel="stylesheet"> + <link href="/list.css" rel="stylesheet"> + <link href="/favicon.png" rel="icon" sizes="192x192" type="image/png"> + <meta charset="utf-8"> + <meta name="viewport" content="width=device-width, initial-scale=1"> + <script type="text/x-mathjax-config">MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']]}});</script> + <script crossorigin="anonymous" integrity="sha384-Ra6zh6uYMmH5ydwCqqMoykyf1T/+ZcnOQfFPhDrp2kI4OIxadnhsvvA2vv9A7xYv" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML" type="text/javascript"></script></head> + <body> + <h1>SRFI 228: Composing Comparators</h1> + <p class="authors">by Daphne Preston-Kendal</p> + <p class="based-on"></p> + <p class="status">status: <em>draft</em> (2021-08-28)</p> + <p class="keywords">keywords: <a href="https://srfi.schemers.org/?keywords=comparison">Comparison</a></p><span class="see-also">See also <a href="/srfi-128/">SRFI 128: Comparators (reduced)</a> and <a href="/srfi-162/">SRFI 162: Comparators sublibrary</a>.</span> + <ul class="info"> + <li><a href="srfi-228.html">The SRFI Document</a></li> + <li><a href="https://srfi-email.schemers.org/srfi-228/">Discussion Archive</a></li> + <li><a href="https://github.com/scheme-requests-for-implementation/srfi-228">Git repo (on GitHub)</a></li> + <li><a href="mailto:srfi-228@srfi.schemers.org">srfi-228@<span class="antispam">nospam</span>srfi.schemers.org (subscribers only)</a></li> + <li><span class="firefox-column-workaround"> + <form method="POST" action="https://www.simplelists.com/subscribe.php"> + <div class="title">Subscribe to srfi-228 mailing list</div><input name="email" placeholder="email address" tabindex="1" type="email"><input name="name" placeholder="full name" tabindex="2" type="text"> + <p><input id="sub-digest" name="digest" tabindex="3" type="checkbox" value="digest"><label for="sub-digest">daily digest?</label></p><input class="submit" name="submit" tabindex="4" type="submit" value="Subscribe to srfi-228"><input type="hidden" name="action" value="subscribe"><input type="hidden" name="list" value="srfi-228@srfi.schemers.org"></form></span></li> + <li><span class="firefox-column-workaround"> + <form method="POST" action="https://www.simplelists.com/subscribe.php"> + <div class="title">Unsubscribe from srfi-228 mailing list</div><input name="email" placeholder="email address" tabindex="5" type="email"><input class="submit" name="submit" tabindex="6" type="submit" value="Unsubscribe from srfi-228"><input type="hidden" name="action" value="unsubscribe"><input name="list" type="hidden" value="srfi-228@srfi.schemers.org"></form></span></li></ul> + <h2>Abstract</h2><p>Further procedures for defining <a href="https://srfi.schemers.org/srfi-128/">SRFI 128</a> comparators. - <body> - <h1>SRFI 228: A further comparator library</h1> - <p class="authors">by Daphne Preston-Kendal</p> - <p class="based-on"></p> - <p class="status">status: <em>draft</em> (2021-08-28)</p> - <p class="keywords">keywords: <a href="https://srfi.schemers.org/?keywords=comparison">Comparison</a></p> - - <ul class="info"> - <li><a href="srfi-228.html">The SRFI Document</a></li> - <li><a href="https://srfi-email.schemers.org/srfi-228/">Discussion Archive</a></li> - <li><a href="https://github.com/scheme-requests-for-implementation/srfi-228">Git repo (on Github)</a></li> - <li> - <a href="mailto:srfi-228@srfi.schemers.org">srfi-228@<span class="antispam">nospam</span>srfi.schemers.org (subscribers only)</a></li> - <li> - <span class="firefox-column-workaround"> - <form method="POST" action="https://www.simplelists.com/subscribe.php"> - <div class="title">Subscribe to srfi-228 mailing list</div> - <input name="email" - placeholder="email address" - tabindex="1" - type="email" > - <input name="name" - placeholder="full name" - tabindex="2" - type="text" > - <p> - <input id="sub-digest" - name="digest" - tabindex="3" - type="checkbox" - value="digest" > - <label for="sub-digest">daily digest?</label></p> - <input class="submit" - name="submit" - tabindex="4" - type="submit" - value="Subscribe to srfi-228" > - <input type="hidden" name="action" value="subscribe"> - <input type="hidden" name="list" value="srfi-228@srfi.schemers.org"></form></a></li> - <li> - <span class="firefox-column-workaround"> - <form method="POST" action="https://www.simplelists.com/subscribe.php"> - <p class="title">Unsubscribe from srfi-228 mailing list</p> - <input name="email" - placeholder="email address" - tabindex="5" - type="email" > - <input class="submit" - name="submit" - tabindex="6" - type="submit" - value="Unsubscribe from srfi-228" > - <input name="action" - type="hidden" - value="unsubscribe" > - <input name="list" - type="hidden" - value="srfi-228@srfi.schemers.org"></form></a></li></ul> - <h2>Abstract</h2><p>Further procedures and syntax forms for defining <a href="https://srfi.schemers.org/srfi-128/srfi-128.html">SRFI 128</a> comparators, and for extracting comparison procedures similar to those defined for Scheme’s built-in types using them. - -<p>Best enjoyed in combination with <a href="https://srfi.schemers.org/srfi-162/srfi-162.html">SRFI 162</a>.</body></html>
\ No newline at end of file +<p>Best enjoyed in combination with <a href="https://srfi.schemers.org/srfi-162/">SRFI 162</a>.</body></html>
\ No newline at end of file diff --git a/srfi-228-test.scm b/srfi-228-test.scm new file mode 100644 index 0000000..85814bb --- /dev/null +++ b/srfi-228-test.scm @@ -0,0 +1,83 @@ +(cond-expand + (chibi + (import (chibi test) + (scheme base) + (srfi 1) + (srfi 128) + (only (srfi 132) list-sort)))) + +(define-record-type Person + (make-person first-name last-name) + person? + (first-name person-first-name) + (last-name person-last-name)) + +(define person-name-comparator + (make-product-comparator + (make-wrapper-comparator person? person-last-name string-ci-comparator) + (make-wrapper-comparator person? person-first-name string-ci-comparator))) + +(test-group "simple" + (test-equal eq? + #t + (<? person-name-comparator + (make-person "John" "Cowan") + (make-person "Daphne" "Preston-Kendal"))) + + (test-equal eq? + #t + (>? person-name-comparator + (make-person "Tom" "Smith") + (make-person "John" "Smith")))) + +(define-record-type Book + (make-book author title) + book? + (author book-author) + (title book-title)) + +(define book-comparator + (make-product-comparator + (make-wrapper-comparator book? book-author person-name-comparator) + (make-wrapper-comparator book? book-title string-ci-comparator))) + +(define-record-type CD + (make-cd artist title) + cd? + (artist cd-artist) + (title cd-title)) + +(define cd-comparator + (make-product-comparator + (make-wrapper-comparator cd? cd-artist person-name-comparator) + (make-wrapper-comparator cd? cd-title string-ci-comparator))) + +(define item-comparator + (make-sum-comparator book-comparator cd-comparator)) + +(test-group "nested" + (let* ((beatles (make-person "The" "Beatles")) + (abbey-road (make-cd beatles "Abbey Road")) + (deutsche-grammatik + (make-book (make-person "Jacob" "Grimm") "Deutsche Grammatik")) + (sonnets (make-book (make-person "William" "Shakespeare") "Sonnets")) + (mnd (make-book (make-person "William" "Shakespeare") + "A Midsummer Night’s Dream")) + (bob (make-cd (make-person "Bob" "Dylan") "Blonde on Blonde")) + (revolver (make-cd (make-person "The" "Beatles") "Revolver"))) + (test-equal + equal? + (list-sort + (lambda (a b) (<? item-comparator a b)) + (list abbey-road + deutsche-grammatik + sonnets + mnd + bob + revolver)) + (list deutsche-grammatik + mnd + sonnets + abbey-road + revolver + bob))))
\ No newline at end of file diff --git a/srfi-228.html b/srfi-228.html index ba54b5a..76aee7f 100644 --- a/srfi-228.html +++ b/srfi-228.html @@ -25,13 +25,14 @@ <li>60-day deadline: 2021-10-30</li> <li>Draft #1 published: 2021-08-31</li> <li>Draft #2 published: 2022-02-26</li> + <li>Draft #3 published: 2022-11-14</li> </ul> <h2 id="abstract">Abstract</h2> -<p>Further procedures for defining <a href="https://srfi.schemers.org/srfi-128/srfi-128.html">SRFI 128</a> comparators. +<p>Further procedures for defining <a href="https://srfi.schemers.org/srfi-128/">SRFI 128</a> comparators. -<p>Best enjoyed in combination with <a href="https://srfi.schemers.org/srfi-162/srfi-162.html">SRFI 162</a>. +<p>Best enjoyed in combination with <a href="https://srfi.schemers.org/srfi-162/">SRFI 162</a>. <h2 id="issues">Issues</h2> @@ -189,7 +190,7 @@ <h2 id=future-work>Future Work</h2> -<p>The author hopes that a future SRFI will add a procedure for creating comparators yielding lexicographical order over any sequence type by delegating to a common iteration protocol. An idea to do this using <code>fold</code> procedures foundered on two grounds: the first and more intrinsic one is that <code>fold</code> called on two sequences, one of which is a prefix of the other, cannot determine which of the two is longer, and a sort using <code>fold</code>-based iteration would incorrectly consider them equal; the second is that there is currently an inconsistency among Scheme libraries in what order the <var>kons</var> procedure argument to <code>fold</code> receives the accumulator and the next values in the sequence (compare <a href="https://srfi.schemers.org/srfi-1/srfi-1.html#fold">SRFI 1 <code>fold</code></a> with <a href="https://srfi.schemers.org/srfi-133/srfi-133.html#vector-fold">SRFI 133 <code>vector-fold</code></a>). <a href="https://srfi.schemers.org/srfi-158/srfi-158.html">SRFI 158</a> generators were rejected on the ground that their sequences cannot contain any arbitrary Scheme datum. +<p>The author hopes that a future SRFI will add a procedure for creating comparators yielding lexicographical order over any sequence type by delegating to a common iteration protocol. An idea to do this using <code>fold</code> procedures foundered on two grounds: the first and more intrinsic one is that <code>fold</code> called on two sequences, one of which is a prefix of the other, cannot determine which of the two is longer, and a sort using <code>fold</code>-based iteration would incorrectly consider them equal; the second is that there is currently an inconsistency among Scheme libraries in what order the <var>kons</var> procedure argument to <code>fold</code> receives the accumulator and the next values in the sequence (compare <a href="https://srfi.schemers.org/srfi-1/srfi-1.html#fold">SRFI 1 <code>fold</code></a> with <a href="https://srfi.schemers.org/srfi-133/srfi-133.html#vector-fold">SRFI 133 <code>vector-fold</code></a>). <a href="https://srfi.schemers.org/srfi-158/">SRFI 158</a> generators were rejected on the ground that their sequences cannot contain any arbitrary Scheme datum. <p>Earlier drafts of this SRFI contained a procedure to convert a SRFI 128 comparator into a set of Scheme comparison procedures. This was dropped because a satisfactory interface, with sufficient efficiency and usability, could not be found. Thanks are due nonetheless to John Cowan and Marc Nieper-Wißkirchen for their suggestions to resolve this issue. Likewise, it is hoped that a future SRFI will respond to this need. diff --git a/srfi/228.sld b/srfi/228.sld index b3cca89..834f1ce 100644 --- a/srfi/228.sld +++ b/srfi/228.sld @@ -1,10 +1,9 @@ (define-library (srfi 228) (import (scheme base) - (srfi 1) + (srfi 1) (srfi 128) - (srfi 151)) + (srfi 151)) (export make-wrapper-comparator make-product-comparator make-sum-comparator) - - (include "composing-comparators.scm")) + (include "srfi-228.scm")) diff --git a/srfi/composing-comparators.scm b/srfi/srfi-228.scm index 3a93ae4..caca339 100644 --- a/srfi/composing-comparators.scm +++ b/srfi/srfi-228.scm @@ -84,4 +84,7 @@ (let ((cmp (%sum-comparator-for comparators x x))) ((comparator-hash-function (car cmp)) x))) #f))) +<<<<<<<< HEAD:srfi/composing-comparators.scm +======== +>>>>>>>> 58c55b3dfe6ebdfd8770cd69ac08acda24dc4f50:srfi/srfi-228.scm |