From a0f0a9052782528fe2c8fea522beb88469fd1ace Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Wed, 8 Feb 2017 00:21:45 -0800
Subject: [PATCH] Implement "computed" character sets.

Also define Unicode symbol characters.
---
 src/runtime/char.scm    |  4 +++
 src/runtime/chrset.scm  | 76 +++++++++++++++++++++++++++++++++++++++++
 src/runtime/runtime.pkg |  4 +++
 3 files changed, 84 insertions(+)

diff --git a/src/runtime/char.scm b/src/runtime/char.scm
index 860a65819..6943d2fe6 100644
--- a/src/runtime/char.scm
+++ b/src/runtime/char.scm
@@ -397,6 +397,10 @@ USA.
   (guarantee unicode-char? char 'char-general-category)
   (ucd-gc-value (char->integer char)))
 
+(define (unicode-code-point-general-category cp)
+  (guarantee unicode-code-point? cp 'unicode-code-point-general-category)
+  (ucd-gc-value cp))
+
 (define-integrable (utf16-surrogate? cp)
   (fix:= #xD800 (fix:and #xF800 cp)))
 
diff --git a/src/runtime/chrset.scm b/src/runtime/chrset.scm
index d03aedc0f..e2db46da6 100644
--- a/src/runtime/chrset.scm
+++ b/src/runtime/chrset.scm
@@ -283,6 +283,43 @@ USA.
 			       (cdr ranges))))))
 	(values low '()))))
 
+(define (compute-char-set procedure)
+  (%make-char-set (%compute-low procedure)
+		  (%code-points->high (%compute-high-ranges procedure))))
+
+(define (%compute-low procedure)
+  (let ((low (%make-low 0)))
+    (do ((cp 0 (fix:+ cp 1)))
+	((not (fix:< cp %low-limit)))
+      (if (procedure cp)
+	  (%low-set! low cp)))
+    low))
+
+(define (%compute-high-ranges procedure)
+  (append! (%compute-high-ranges-1 %low-limit #xD800 procedure)
+	   (%compute-high-ranges-1 #xE000 char-code-limit procedure)))
+
+(define (%compute-high-ranges-1 start end procedure)
+  (define (find-start cp ranges)
+    (if (fix:< cp end)
+	(if (procedure cp)
+	    (find-end (fix:+ cp 1) cp ranges)
+	    (find-start (fix:+ cp 1) ranges))
+	(done ranges)))
+
+  (define (find-end cp start ranges)
+    (if (fix:< cp end)
+	(if (procedure cp)
+	    (find-end (fix:+ cp 1) start ranges)
+	    (find-start (fix:+ cp 1)
+			(cons (%make-range start cp) ranges)))
+	(done (cons (%make-range start end) ranges))))
+
+  (define (done ranges)
+    (reverse! ranges))
+
+  (find-start start '()))
+
 ;;;; Predicates
 
 (define (char-in-set? char char-set)
@@ -569,6 +606,45 @@ USA.
 (define-deferred char-set:wsp (char-set #\space #\tab))
 (define-deferred char-wsp? (char-set-predicate char-set:wsp))
 
+;;;; Scheme language:
+
+(define (symbol-constituent? sv)
+  (lambda (sv)
+    (case sv
+      ;; #\" #\# #\' #\, #\; #\\ #\` #\|
+      ((#x22 #x23 #x27 #x2c #x3b #x5c #x60 #x7c) #f)
+      ((#x200C #x200D) #t)
+      (else
+       (case (unicode-code-point-general-category sv)
+	 ((letter:uppercase
+	   letter:lowercase
+	   letter:titlecase
+	   letter:modifier
+	   letter:other
+	   mark:nonspacing
+	   number:letter
+	   number:other
+	   punctuation:connector
+	   punctuation:dash
+	   punctuation:other
+	   symbol:math
+	   symbol:currency
+	   symbol:modifier
+	   symbol:other
+	   other:private-use)
+	  #t)
+	 ((mark:spacing-combining
+	   mark:enclosing
+	   number:decimal-digit)
+	  'subsequent-only)
+	 (else #f))))))
+
+(define-deferred char-set:symbol-constituent
+  (compute-char-set symbol-constituent?))
+
+(define-deferred char-set:symbol-initial
+  (compute-char-set (lambda (sv) (eq? #t (symbol-constituent? sv)))))
+
 ;;;; Backwards compatibility
 
 (define (char-set-member? char-set char)
diff --git a/src/runtime/runtime.pkg b/src/runtime/runtime.pkg
index 534d86517..488770846 100644
--- a/src/runtime/runtime.pkg
+++ b/src/runtime/runtime.pkg
@@ -1393,6 +1393,7 @@ USA.
 	  set-char-bits
 	  unicode-char->scalar-value
 	  unicode-char?
+	  unicode-code-point-general-category
 	  unicode-code-point?
 	  unicode-scalar-value->char
 	  unicode-scalar-value?))
@@ -1500,6 +1501,8 @@ USA.
 	  char-set:upper-case
 	  char-set:whitespace
 	  char-set:wsp
+	  char-set:symbol-constituent
+	  char-set:symbol-initial
 	  char-set=?
 	  char-set?
 	  char-standard?
@@ -1508,6 +1511,7 @@ USA.
 	  char-wsp?
 	  code-point-list?
 	  char-set*
+	  compute-char-set
 	  scalar-value-in-char-set?
 	  string->char-set)
   (export (runtime string)
-- 
2.25.1