less garbage during indexing (-30M for IDEA project), just in case each TokenSet is 5K each

java/java-psi-api/src/com/intellij/lexer/JavaDocTokenTypes.java

@@ -17,12 +17,14 @@ package com.intellij.lexer;
 
 import com.intellij.psi.JavaDocTokenType;
 import com.intellij.psi.tree.IElementType;
+import com.intellij.psi.tree.TokenSet;
 
 /**
  * @author yole
  */
 public class JavaDocTokenTypes implements DocCommentTokenTypes {
   public static final DocCommentTokenTypes INSTANCE = new JavaDocTokenTypes();
+  private final TokenSet mySpaceCommentsSet = TokenSet.create(JavaDocTokenType.DOC_SPACE, JavaDocTokenType.DOC_COMMENT_DATA);
 
   private JavaDocTokenTypes() { }
 
@@ -41,6 +43,11 @@ public class JavaDocTokenTypes implements DocCommentTokenTypes {
     return JavaDocTokenType.DOC_COMMENT_DATA;
   }
 
+  @Override
+  public TokenSet spaceCommentsTokenSet() {
+    return mySpaceCommentsSet;
+  }
+
   @Override
   public IElementType space() {
     return JavaDocTokenType.DOC_SPACE;

platform/core-api/src/com/intellij/lexer/DocCommentLexer.java

@@ -16,7 +16,6 @@
 package com.intellij.lexer;
 
 import com.intellij.psi.tree.IElementType;
-import com.intellij.psi.tree.TokenSet;
 import com.intellij.util.text.CharArrayUtil;
 
 import java.io.IOException;
@@ -24,7 +23,7 @@ import java.io.IOException;
 public class DocCommentLexer extends MergingLexerAdapter {
   public DocCommentLexer(final DocCommentTokenTypes tokenTypes, final boolean isJdk15Enabled) {
     super(new AsteriskStripperLexer(new _JavaDocLexer(isJdk15Enabled, tokenTypes), tokenTypes),
-          TokenSet.create(tokenTypes.commentData(), tokenTypes.space()));
+          tokenTypes.spaceCommentsTokenSet());
   }
 
   private static class AsteriskStripperLexer extends LexerBase {

platform/core-api/src/com/intellij/lexer/DocCommentTokenTypes.java

@@ -17,6 +17,7 @@
 package com.intellij.lexer;
 
 import com.intellij.psi.tree.IElementType;
+import com.intellij.psi.tree.TokenSet;
 
 /**
  * Allows to specify a set of language-dependent token types for the doc comment lexer.
@@ -27,6 +28,7 @@ public interface DocCommentTokenTypes {
   IElementType commentStart();
   IElementType commentEnd();
   IElementType commentData();
+  TokenSet spaceCommentsTokenSet();
   IElementType space();
   IElementType tagValueToken();
   IElementType tagValueLParen();