Fix is_public_assigned to include Hangul Syllable and other ranges.

Hangul Syllables and several other ranges are defined in UnicodeData.txt
as just their first and last values:

```
AC00;<Hangul Syllable, First>;Lo;0;L;;;;;N;;;;;
D7A3;<Hangul Syllable, Last>;Lo;0;L;;;;;N;;;;;
```

Teach the unicode.py script how to recognize these, so that it correctly
classifies them as assigned ranges, for the `is_public_assigned`
predicate.

Author: sunfishcode

scripts/unicode.py

@@ -102,12 +102,13 @@ def _load_unicode_data(self):
 
         assigned_start = 0;
         prev_char_int = -1;
+        prev_name = "";
 
         for line in self._fetch("UnicodeData.txt").splitlines():
             # See ftp://ftp.unicode.org/Public/3.0-Update/UnicodeData-3.0.0.html
             pieces = line.split(';')
             assert len(pieces) == 15
-            char, category, cc, decomp = pieces[0], pieces[2], pieces[3], pieces[5]
+            char, name, category, cc, decomp = pieces[0], pieces[1], pieces[2], pieces[3], pieces[5]
             char_int = int(char, 16)
 
             name = pieces[1].strip()
@@ -126,10 +127,11 @@ def _load_unicode_data(self):
 
             assert category != 'Cn', "Unexpected: Unassigned codepoint in UnicodeData.txt"
             if category not in ['Co', 'Cs']:
-                if char_int != prev_char_int + 1:
+                if char_int != prev_char_int + 1 and not is_first_and_last(prev_name, name):
                     self.general_category_public_assigned.append((assigned_start, prev_char_int))
                     assigned_start = char_int
                 prev_char_int = char_int
+                prev_name = name;
 
         self.general_category_public_assigned.append((assigned_start, prev_char_int))
 
@@ -343,6 +345,15 @@ def _compute_stream_safe_tables(self):
 
 hexify = lambda c: '{:04X}'.format(c)
 
+# Test whether `first` and `last` are corresponding "<..., First>" and
+# "<..., Last>" markers.
+def is_first_and_last(first, last):
+    if not first.startswith('<') or not first.endswith(', First>'):
+        return False
+    if not last.startswith('<') or not last.endswith(', Last>'):
+        return False
+    return first[1:-8] == last[1:-7]
+
 def gen_mph_data(name, d, kv_type, kv_callback):
     (salt, keys) = minimal_perfect_hash(d)
     out.write("pub(crate) const %s_SALT: &[u16] = &[\n" % name.upper())

src/tables.rs

@@ -22051,9 +22051,7 @@ pub fn is_public_assigned(c: char) -> bool {
         | '\u{3131}'..='\u{318E}'
         | '\u{3190}'..='\u{31E3}'
         | '\u{31F0}'..='\u{321E}'
-        | '\u{3220}'..='\u{3400}'
-        | '\u{4DBF}'..='\u{4E00}'
-        | '\u{9FFC}'
+        | '\u{3220}'..='\u{9FFC}'
         | '\u{A000}'..='\u{A48C}'
         | '\u{A490}'..='\u{A4C6}'
         | '\u{A4D0}'..='\u{A62B}'
@@ -22083,8 +22081,7 @@ pub fn is_public_assigned(c: char) -> bool {
         | '\u{AB30}'..='\u{AB6B}'
         | '\u{AB70}'..='\u{ABED}'
         | '\u{ABF0}'..='\u{ABF9}'
-        | '\u{AC00}'
-        | '\u{D7A3}'
+        | '\u{AC00}'..='\u{D7A3}'
         | '\u{D7B0}'..='\u{D7C6}'
         | '\u{D7CB}'..='\u{D7FB}'
         | '\u{F900}'..='\u{FA6D}'
@@ -22305,11 +22302,9 @@ pub fn is_public_assigned(c: char) -> bool {
         | '\u{16F8F}'..='\u{16F9F}'
         | '\u{16FE0}'..='\u{16FE4}'
         | '\u{16FF0}'..='\u{16FF1}'
-        | '\u{17000}'
-        | '\u{187F7}'
+        | '\u{17000}'..='\u{187F7}'
         | '\u{18800}'..='\u{18CD5}'
-        | '\u{18D00}'
-        | '\u{18D08}'
+        | '\u{18D00}'..='\u{18D08}'
         | '\u{1B000}'..='\u{1B11E}'
         | '\u{1B150}'..='\u{1B152}'
         | '\u{1B164}'..='\u{1B167}'
@@ -22439,19 +22434,13 @@ pub fn is_public_assigned(c: char) -> bool {
         | '\u{1FB00}'..='\u{1FB92}'
         | '\u{1FB94}'..='\u{1FBCA}'
         | '\u{1FBF0}'..='\u{1FBF9}'
-        | '\u{20000}'
-        | '\u{2A6DD}'
-        | '\u{2A700}'
-        | '\u{2B734}'
-        | '\u{2B740}'
-        | '\u{2B81D}'
-        | '\u{2B820}'
-        | '\u{2CEA1}'
-        | '\u{2CEB0}'
-        | '\u{2EBE0}'
+        | '\u{20000}'..='\u{2A6DD}'
+        | '\u{2A700}'..='\u{2B734}'
+        | '\u{2B740}'..='\u{2B81D}'
+        | '\u{2B820}'..='\u{2CEA1}'
+        | '\u{2CEB0}'..='\u{2EBE0}'
         | '\u{2F800}'..='\u{2FA1D}'
-        | '\u{30000}'
-        | '\u{3134A}'
+        | '\u{30000}'..='\u{3134A}'
         | '\u{E0001}'
         | '\u{E0020}'..='\u{E007F}'
         | '\u{E0100}'..='\u{E01EF}'

tests/public_assigned.rs

@@ -71,4 +71,51 @@ fn test_public_assigned() {
     assert!(!is_public_assigned('\u{fffff}'));
     assert!(!is_public_assigned('\u{10fffe}'));
     assert!(!is_public_assigned('\u{10ffff}'));
+
+    // Several ranges are defined by "<..., First>" and "<..., Last>" pairs in
+    // UnicodeData.txt:
+
+    // CJK Ideograph Extension A
+    assert!(is_public_assigned('\u{3400}'));
+    assert!(is_public_assigned('\u{4dbf}'));
+
+    // CJK Ideograph
+    assert!(is_public_assigned('\u{4e00}'));
+    assert!(is_public_assigned('\u{9ffc}'));
+
+    // Hangul Syllable
+    assert!(is_public_assigned('\u{ac00}'));
+    assert!(is_public_assigned('\u{d7a3}'));
+
+    // Tangut Ideograph
+    assert!(is_public_assigned('\u{17000}'));
+    assert!(is_public_assigned('\u{187f7}'));
+
+    // Tangut Ideograph Supplement
+    assert!(is_public_assigned('\u{18d00}'));
+    assert!(is_public_assigned('\u{18d08}'));
+
+    // CJK Ideograph Extension B
+    assert!(is_public_assigned('\u{20000}'));
+    assert!(is_public_assigned('\u{2a6dd}'));
+
+    // CJK Ideograph Extension C
+    assert!(is_public_assigned('\u{2a700}'));
+    assert!(is_public_assigned('\u{2b734}'));
+
+    // CJK Ideograph Extension D
+    assert!(is_public_assigned('\u{2b740}'));
+    assert!(is_public_assigned('\u{2b81d}'));
+
+    // CJK Ideograph Extension E
+    assert!(is_public_assigned('\u{2b820}'));
+    assert!(is_public_assigned('\u{2cea1}'));
+
+    // CJK Ideograph Extension F
+    assert!(is_public_assigned('\u{2ceb0}'));
+    assert!(is_public_assigned('\u{2ebe0}'));
+
+    // CJK Ideograph Extension G
+    assert!(is_public_assigned('\u{30000}'));
+    assert!(is_public_assigned('\u{3134a}'));
 }