fix(JavaDoc): illegal character on escaped array types

GitOrigin-RevId: dd8098159715bd42510d807077d2679b365c546f

java/java-frontback-psi-impl/src/com/intellij/lang/java/lexer/JavaTypeEscapeLexer.java

@@ -0,0 +1,44 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.lang.java.lexer;
+
+import com.intellij.lexer.Lexer;
+import com.intellij.lexer.MergeFunction;
+import com.intellij.lexer.MergingLexerAdapterBase;
+import com.intellij.psi.TokenType;
+import com.intellij.psi.tree.IElementType;
+
+/**
+ * Lexer to wrap around the Java Lexer when parsing Java types for the markdown JavaDoc (JEP-467)
+ * In reference links, array types are escaped:  "char\[\]" which the JavaLexer doesn't like
+ * <p>
+ * It does this by <em>covering up</em> a <i>BAD_CHARACTER</i> token if followed by <i>[</i> or <i>]</i>
+ */
+public class JavaTypeEscapeLexer extends MergingLexerAdapterBase {
+  private final MergeFunction myMergeFunction = new EscapeMarkdownFunction();
+
+  public JavaTypeEscapeLexer(BasicJavaLexer original) {
+    super(original);
+  }
+
+  @Override
+  public MergeFunction getMergeFunction() {
+    return myMergeFunction;
+  }
+
+
+  private static class EscapeMarkdownFunction implements MergeFunction {
+    @Override
+    public IElementType merge(IElementType type, Lexer originalLexer) {
+      if(type != TokenType.BAD_CHARACTER) return type;
+
+      CharSequence tokenText = originalLexer.getTokenSequence();
+      if (tokenText.length() != 1 || (tokenText.charAt(0) != '[' && tokenText.charAt(0) != ']')) {
+        return type;
+      }
+
+      type = originalLexer.getTokenType();
+      originalLexer.advance();
+      return type;
+    }
+  }
+}

java/java-frontback-psi-impl/src/com/intellij/lang/java/parser/BasicJavaParserUtil.java

@@ -193,7 +193,7 @@ public final class BasicJavaParserUtil {
                                       final boolean eatAll,
                                       final LanguageLevel level,
                                       Function<LanguageLevel, JavaDocLexer> javaDocLexer,
-                                      Function<LanguageLevel, BasicJavaLexer> javaLexer) {
+                                      Function<LanguageLevel, ? extends Lexer> javaLexer) {
     final PsiElement psi = chameleon.getTreeParent() != null ? chameleon.getTreeParent().getPsi() : chameleon.getPsi();
     assert psi != null : chameleon;
     final Project project = psi.getProject();

java/java-frontback-psi-impl/src/com/intellij/psi/impl/source/BasicJavaDocElementType.java

@@ -5,6 +5,7 @@ import com.intellij.lang.Language;
 import com.intellij.lang.java.JavaLanguage;
 import com.intellij.lang.java.lexer.BasicJavaLexer;
 import com.intellij.lang.java.lexer.JavaDocLexer;
+import com.intellij.lang.java.lexer.JavaTypeEscapeLexer;
 import com.intellij.lang.java.parser.BasicJavaDocParser;
 import com.intellij.lang.java.parser.BasicJavaParser;
 import com.intellij.lang.java.parser.BasicJavaParserUtil;
@@ -125,11 +126,11 @@ public interface BasicJavaDocElementType {
 
     private final @NotNull Supplier<? extends BasicJavaParser> myJavaThinParser;
     private final Function<LanguageLevel, JavaDocLexer> javaDocLexer;
-    private final Function<LanguageLevel, BasicJavaLexer> javaLexer;
+    private final Function<LanguageLevel, JavaTypeEscapeLexer> javaLexer;
 
     public DocTypeHolderElementType(@NotNull Supplier<? extends BasicJavaParser> parser,
                                     @NotNull Function<LanguageLevel, JavaDocLexer> docLexerFunction,
-                                    @NotNull Function<LanguageLevel, BasicJavaLexer> javaLexer) {
+                                    @NotNull Function<LanguageLevel, JavaTypeEscapeLexer> javaLexer) {
       super("DOC_TYPE_HOLDER", BASIC_DOC_TYPE_HOLDER);
       this.myJavaThinParser = parser;
       this.javaDocLexer = docLexerFunction;

java/java-frontback-psi-impl/src/com/intellij/psi/impl/source/BasicJavaElementType.java

@@ -251,10 +251,10 @@ public interface BasicJavaElementType {
   final class JavaDummyElementType extends ILazyParseableElementType implements ICompositeElementType, ParentProviderElementType {
     private static final Set<IElementType> PARENT_ELEMENT_TYPES = Collections.singleton(BASIC_DUMMY_ELEMENT);
     private final Function<LanguageLevel, JavaDocLexer> javaDocLexer;
-    private final Function<LanguageLevel, BasicJavaLexer> javaLexer;
+    private final Function<LanguageLevel, ? extends Lexer> javaLexer;
 
     public JavaDummyElementType(@NotNull Function<LanguageLevel, JavaDocLexer> lexer,
-                                @NotNull Function<LanguageLevel, BasicJavaLexer> javaLexer) {
+                                @NotNull Function<LanguageLevel, Lexer> javaLexer) {
       super("DUMMY_ELEMENT", JavaLanguage.INSTANCE);
       javaDocLexer = lexer;
       this.javaLexer = javaLexer;