Merge branch 'master' of https://github.com/scheme-requests-for-implementation/srfi-228

4 files changed, 93 insertions, 7 deletions

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