Fixed word boundary patterns: they were ascii-only while java.util.regexp is unicode compliant

Author: mykeul

java/com/google/re2j/Unicode.java

@@ -66,6 +66,11 @@ private static boolean is(int[][] ranges, int r) {
     return ranges.length > 0 && r >= ranges[0][0] && is32(ranges, r);
   }
 
+  // isLetter reports whether the rune is a letter.
+  static boolean isLetter(int r) {
+    return is(UnicodeTables.Letter, r);
+  }
+
   // isUpper reports whether the rune is an upper case letter.
   static boolean isUpper(int r) {
     // See comment in isGraphic.

java/com/google/re2j/Utils.java

@@ -156,9 +156,9 @@ static int indexOf(byte[] source, byte[] target, int fromIndex) {
 
   // isWordRune reports whether r is consider a ``word character''
   // during the evaluation of the \b and \B zero-width assertions.
-  // These assertions are ASCII-only: the word characters are [A-Za-z0-9_].
+  // These assertions are unicode compliant: the word characters are [\p{L}-z0-9_].
   static boolean isWordRune(int r) {
-    return (('A' <= r && r <= 'Z') || ('a' <= r && r <= 'z') || ('0' <= r && r <= '9') || r == '_');
+    return (Unicode.isLetter(r) || ('0' <= r && r <= '9') || r == '_');
   }
 
   //// EMPTY_* flags

javatests/com/google/re2j/PatternTest.java

@@ -193,4 +193,57 @@ public void testEquals() {
     Truth.assertThat(pattern1.hashCode()).isEqualTo(pattern2.hashCode());
     Truth.assertThat(pattern1).isNotEqualTo(pattern4);
   }
+
+  @Test
+  public void testUnicodeWordBoundary() {
+    final String pattern = "l\\p{L}*\\b";
+    final String text = "l\u00E0";
+    {
+      final java.util.regex.Matcher matcher =
+          java.util.regex.Pattern.compile(pattern).matcher(text);
+      assertEquals(true, matcher.find());
+      assertEquals("l\u00E0", text.substring(matcher.start(), matcher.end()));
+    }
+    {
+      final com.google.re2j.Matcher matcher =
+          com.google.re2j.Pattern.compile(pattern).matcher(text);
+      assertEquals(true, matcher.find());
+      assertEquals("l\u00E0", text.substring(matcher.start(), matcher.end()));
+    }
+  }
+
+  @Test
+  public void testUnicodeWordBoundary2() {
+    final String pattern = "d\u00E9\\p{L}*\\b";
+    {
+      final String text = "d\u00E9s";
+      {
+        final java.util.regex.Matcher matcher =
+            java.util.regex.Pattern.compile(pattern).matcher(text);
+        assertEquals(true, matcher.find());
+        assertEquals("d\u00E9s", text.substring(matcher.start(), matcher.end()));
+      }
+      {
+        final com.google.re2j.Matcher matcher =
+            com.google.re2j.Pattern.compile(pattern).matcher(text);
+        assertEquals(true, matcher.find());
+        assertEquals("d\u00E9s", text.substring(matcher.start(), matcher.end()));
+      }
+    }
+    {
+      final String text = "d\u00E9";
+      {
+        final java.util.regex.Matcher matcher =
+            java.util.regex.Pattern.compile(pattern).matcher(text);
+        assertEquals(true, matcher.find());
+        assertEquals("d\u00E9", text.substring(matcher.start(), matcher.end()));
+      }
+      {
+        final com.google.re2j.Matcher matcher =
+            com.google.re2j.Pattern.compile(pattern).matcher(text);
+        assertEquals(true, matcher.find());
+        assertEquals("d\u00E9", text.substring(matcher.start(), matcher.end()));
+      }
+    }
+  }
 }