From 23045820895cb3087e1f765c7574e754d9c9816f Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Fri, 10 Feb 2017 20:40:46 -0800
Subject: [PATCH] Implement char-foldcase and ustring-foldcase.

Also fix implementations of ustring-{up,down}case.
---
 src/runtime/char.scm    | 16 +++++++--------
 src/runtime/runtime.pkg | 14 +++++++++++--
 src/runtime/ustring.scm | 45 +++++++++++++++++++++++++++++------------
 3 files changed, 51 insertions(+), 24 deletions(-)

diff --git a/src/runtime/char.scm b/src/runtime/char.scm
index 5bf608cdc..d413d9e7c 100644
--- a/src/runtime/char.scm
+++ b/src/runtime/char.scm
@@ -118,7 +118,7 @@ USA.
   (fix:>= (char-ci->integer x) (char-ci->integer y)))
 
 (define-integrable (char-ci->integer char)
-  (char->integer (char-upcase char)))
+  (ucd-scf-value (char->integer char)))
 
 (define (char=-predicate char)
   (guarantee char? char 'char=-predicate)
@@ -132,17 +132,15 @@ USA.
 
 (define (char-downcase char)
   (guarantee unicode-char? char 'char-downcase)
-  (let ((cp (ucd-slc-value (char->integer char))))
-    (if (index-fixnum? cp)
-	(integer->char cp)
-	char)))
+  (integer->char (ucd-slc-value (char->integer char))))
+
+(define (char-foldcase char)
+  (guarantee unicode-char? char 'char-foldcase)
+  (integer->char (ucd-scf-value (char->integer char))))
 
 (define (char-upcase char)
   (guarantee unicode-char? char 'char-upcase)
-  (let ((cp (ucd-suc-value (char->integer char))))
-    (if (index-fixnum? cp)
-	(integer->char cp)
-	char)))
+  (integer->char (ucd-suc-value (char->integer char))))
 
 (define-deferred 0-code (char->integer #\0))
 ;; Next two codes are offset by 10 to speed up CHAR->DIGIT.
diff --git a/src/runtime/runtime.pkg b/src/runtime/runtime.pkg
index e1020f50c..16a20778c 100644
--- a/src/runtime/runtime.pkg
+++ b/src/runtime/runtime.pkg
@@ -1177,7 +1177,7 @@ USA.
 	  ustring-find-last-char	 ;prefer ustring-find-last-index
 	  ustring-find-last-char-in-set	 ;prefer ustring-find-last-index
 	  ustring-find-last-index
-	  ;; ustring-foldcase
+	  ustring-foldcase
 	  ustring-for-each
 	  ustring-hash
 	  ustring-head
@@ -1357,6 +1357,7 @@ USA.
 	  char-code
 	  char-code-limit
 	  char-downcase
+	  char-foldcase
 	  char-general-category
 	  char-integer-limit
 	  char-upcase
@@ -1400,11 +1401,15 @@ USA.
 
 (define-package (runtime ucd-tables)
   (files "ucd-table-alpha"
+	 "ucd-table-cf"
 	 "ucd-table-gc"
+	 "ucd-table-lc"
 	 "ucd-table-lower"
 	 "ucd-table-nt"
+	 "ucd-table-scf"
 	 "ucd-table-slc"
 	 "ucd-table-suc"
+	 "ucd-table-uc"
 	 "ucd-table-upper"
 	 "ucd-table-wspace")
   (parent (runtime))
@@ -1415,10 +1420,15 @@ USA.
 	  char-set:upper-case)
   (export (runtime character)
 	  ucd-gc-value
+	  ucd-scf-value
 	  ucd-slc-value
 	  ucd-suc-value)
   (export (runtime ucd-table-glue)
-	  ucd-nt-value))
+	  ucd-nt-value)
+  (export (runtime ustring)
+	  ucd-cf-value
+	  ucd-lc-value
+	  ucd-uc-value))
 
 (define-package (runtime ucd-table-glue)
   (files "ucd-table-glue")
diff --git a/src/runtime/ustring.scm b/src/runtime/ustring.scm
index b2c97ecd0..24a6306df 100644
--- a/src/runtime/ustring.scm
+++ b/src/runtime/ustring.scm
@@ -236,15 +236,29 @@ USA.
 			(utf32-string-ref string i))
 		      strings))))))
 
-;; Incorrect implementation
-(define (utf32-string-upcase string)
-  (utf32-string-map char-upcase string))
-
-;; Incorrect implementation
 (define (utf32-string-downcase string)
-  (utf32-string-map char-downcase string))
+  (utf32-case-transform string ucd-lc-value 'utf32-string-downcase))
 
-;; Random and probably incorrect.
+(define (utf32-string-foldcase string)
+  (utf32-case-transform string ucd-cf-value 'utf32-string-foldcase))
+
+(define (utf32-string-upcase string)
+  (utf32-case-transform string ucd-uc-value 'utf32-string-upcase))
+
+(define (utf32-case-transform string sv-transform caller)
+  (let ((svs
+	 (append-map (lambda (char)
+		       (sv-transform (char->integer char)))
+		     (utf32-string->list string))))
+    (let ((n (length svs)))
+      (let ((result (make-utf32-string n)))
+	(do ((svs svs (cdr svs))
+	     (i 0 (fix:+ i 1)))
+	    ((not (pair? svs)))
+	  (utf32-string-set! result i (integer->char (car svs))))
+	result))))
+
+;; Incorrect, needs title-case implementation
 (define (utf32-string-capitalize string)
   (let ((index (utf32-string-find-first-index char-alphabetic? string))
 	(string (utf32-string-copy string)))
@@ -414,7 +428,7 @@ USA.
   (and (fix:= (ustring-length string1) (ustring-length string2))
        (ustring-every char-ci=? string1 string2)))
 
-;; Incorrect implementation.
+;; Non-Unicode implementation, acceptable to R7RS.
 (define-integrable (%string-comparison-maker c= c<)
   (lambda (string1 string2)
     (let ((end1 (ustring-length string1))
@@ -649,16 +663,21 @@ USA.
 (define (ustring-find-last-char-in-set string char-set #!optional start end)
   (ustring-find-last-index (char-set-predicate char-set) string start end))
 
-(define (ustring-upcase string)
-  (cond ((legacy-string? string) (legacy-string-upcase string))
-	((utf32-string? string) (utf32-string-upcase string))
-	(else (error:not-a ustring? string 'ustring-upcase))))
-
 (define (ustring-downcase string)
   (cond ((legacy-string? string) (legacy-string-downcase string))
 	((utf32-string? string) (utf32-string-downcase string))
 	(else (error:not-a ustring? string 'ustring-downcase))))
 
+(define (ustring-foldcase string)
+  (cond ((legacy-string? string) (legacy-string-downcase string))
+	((utf32-string? string) (utf32-string-foldcase string))
+	(else (error:not-a ustring? string 'ustring-foldcase))))
+
+(define (ustring-upcase string)
+  (cond ((legacy-string? string) (legacy-string-upcase string))
+	((utf32-string? string) (utf32-string-upcase string))
+	(else (error:not-a ustring? string 'ustring-upcase))))
+
 (define (ustring-capitalize string)
   (cond ((legacy-string? string) (legacy-string-capitalize string))
 	((utf32-string? string) (utf32-string-capitalize string))
-- 
2.25.1