Improved documentation, removed union fram change note.

Author: Napalys

javascript/extractor/src/com/semmle/js/ast/regexp/CharacterClassIntersection.java

@@ -3,6 +3,10 @@
 import com.semmle.js.ast.SourceLocation;
 import java.util.List;
 
+/**
+ * A character class intersection in a regular expression available only with the `v` flag.
+ * Example: [[abc]&&[ab]&&[b]] matches character `b` only.
+ */
 public class CharacterClassIntersection extends RegExpTerm {
     private final List<RegExpTerm> elements;
 

javascript/extractor/src/com/semmle/js/ast/regexp/CharacterClassQuotedString.java

@@ -3,8 +3,11 @@
 import com.semmle.js.ast.SourceLocation;
 
 /**
- * A '\q{}' escape sequence in a regular expression, which is a special extension
- * to standard regular expressions.
+ * A quoted string escape sequence '\q{}' in a regular expression.
+ * This feature is a non-standard extension that requires the 'v' flag.
+ * 
+ * Example: [\q{abc|def}] creates a character class that matches either the string
+ * "abc" or "def". Within the quoted string, only the alternation operator '|' is supported.
  */
 public class CharacterClassQuotedString extends RegExpTerm {
   private final RegExpTerm term;
@@ -17,7 +20,7 @@ public CharacterClassQuotedString(SourceLocation loc, RegExpTerm term) {
   public RegExpTerm getTerm() {
     return term;
   }
-
+  
   @Override
   public void accept(Visitor v) {
     v.visit(this);

javascript/extractor/src/com/semmle/js/ast/regexp/CharacterClassSubtraction.java

@@ -3,6 +3,10 @@
 import com.semmle.js.ast.SourceLocation;
 import java.util.List;
 
+/**
+ * A character class subtraction in a regular expression available only with the `v` flag.
+ * Example: [[abc]--[a]--[b]] matches character `c` only.
+ */
 public class CharacterClassSubtraction extends RegExpTerm {
     private final List<RegExpTerm> elements;
 

javascript/extractor/src/com/semmle/js/parser/RegExpParser.java

@@ -297,8 +297,8 @@ private RegExpTerm parseDisjunctionInsideQuotedString() {
         disjuncts.add(this.parseAlternativeInsideQuotedString());
     }
     if (disjuncts.size() == 1) return disjuncts.get(0);
-        return this.finishTerm(new Disjunction(loc, disjuncts));
-  }
+    return this.finishTerm(new Disjunction(loc, disjuncts));
+    }
 
   private RegExpTerm parseAlternativeInsideQuotedString() {
     SourceLocation loc = new SourceLocation(pos());

javascript/ql/lib/change-notes/2025-03-03-regex-v.md

@@ -4,5 +4,4 @@ category: feature
 * Added ability to parse new ECMA 2024 `v` flag operations:
   - Intersection `&&`
   - Subtraction `--`
-  - Union
   - `\q` quoted string