How to use

getHiddenTokensToLeft

method

in

org.antlr.v4.runtime.CommonTokenStream

protected List<Comment> getComments(ParserRuleContext ctx) {
  Token start = ctx.getStart();
  if (start != null) {
    int tokPos = start.getTokenIndex();
    List<Token> refChannel = tokens.getHiddenTokensToLeft(tokPos, CHANNEL_COMMENTS);
    if (refChannel != null) {
      return getCommentOnChannel(refChannel);
    }
  }
  return Collections.emptyList();
}

private void addIgnoredChars(ParserRuleContext ctx, NodeBuilder nodeBuilder) {
  Token start = ctx.getStart();
  int tokenStartIndex = start.getTokenIndex();
  List<Token> leftChannel = tokens.getHiddenTokensToLeft(tokenStartIndex, CHANNEL_IGNORED_CHARS);
  List<IgnoredChar> ignoredCharsLeft = mapTokenToIgnoredChar(leftChannel);
  Token stop = ctx.getStop();
  int tokenStopIndex = stop.getTokenIndex();
  List<Token> rightChannel = tokens.getHiddenTokensToRight(tokenStopIndex, CHANNEL_IGNORED_CHARS);
  List<IgnoredChar> ignoredCharsRight = mapTokenToIgnoredChar(rightChannel);
  nodeBuilder.ignoredChars(new IgnoredChars(ignoredCharsLeft, ignoredCharsRight));
}

@SuppressWarnings("unused")
private String buildFunctionBody(ExpressionBodyContext expressionBodyContext){
  StringBuffer sb=new StringBuffer();
  for(ParseTree node:expressionBodyContext.children){
    Interval interval=node.getSourceInterval();
    int index=interval.a;
    List<Token> leftTokens=tokenStream.getHiddenTokensToLeft(index);
    if(leftTokens!=null){
      Token token=leftTokens.get(0);
      String text=token.getText();
      sb.append(text);
    }
    sb.append(node.getText());
    List<Token> rightTokens=tokenStream.getHiddenTokensToRight(index);
    if(rightTokens!=null){
      Token token=rightTokens.get(0);
      String text=token.getText();
      sb.append(text);
    }
  }
  return sb.toString();
}

public static List<Token> getPreviousWS(CommonTokenStream tokens, int i) {
  List<Token> hiddenTokensToLeft = tokens.getHiddenTokensToLeft(i);
  if ( hiddenTokensToLeft==null ) return null;
  return filter(hiddenTokensToLeft, t -> t.getText().matches("\\s+"));
}

@Override
public String visitTerminal(TerminalNode node){
  int index = node.getSymbol().getTokenIndex();
  String lws = tokens.getHiddenTokensToLeft(index) != null ? tokens.getHiddenTokensToLeft(index).stream().map(Token::getText).collect(joining()) : "";
  String rws = tokens.getHiddenTokensToRight(index) != null ? tokens.getHiddenTokensToRight(index).stream().map(Token::getText).collect(joining()) : "";
  return lws + node.getText() + rws;
}

private String lwhitespace(int tokenIndex) {
  List<Token> hidden = tokens.getHiddenTokensToLeft(tokenIndex);
  if(hidden == null){ return ""; }
  Integer newline = newlineOrEOF(hidden);
  newline = newline == null ? 0 : newline;
  return wsFrom(newline, hidden.size(), hidden);
}

@SuppressWarnings("unused")
private String buildFunctionBody(ExpressionBodyContext expressionBodyContext){
  StringBuffer sb=new StringBuffer();
  for(ParseTree node:expressionBodyContext.children){
    Interval interval=node.getSourceInterval();
    int index=interval.a;
    List<Token> leftTokens=tokenStream.getHiddenTokensToLeft(index);
    if(leftTokens!=null){
      Token token=leftTokens.get(0);
      String text=token.getText();
      sb.append(text);
    }
    sb.append(node.getText());
    List<Token> rightTokens=tokenStream.getHiddenTokensToRight(index);
    if(rightTokens!=null){
      Token token=rightTokens.get(0);
      String text=token.getText();
      sb.append(text);
    }
  }
  return sb.toString();
}
 

protected List<Comment> getComments(ParserRuleContext ctx) {
  Token start = ctx.getStart();
  if (start != null) {
    int tokPos = start.getTokenIndex();
    List<Token> refChannel = tokens.getHiddenTokensToLeft(tokPos, CHANNEL_COMMENTS);
    if (refChannel != null) {
      return getCommentOnChannel(refChannel);
    }
  }
  return Collections.emptyList();
}

/** Get start/stop of an entire rule including semi and then clean up
 *  WS at end.
 */
public static String getRuleText(CommonTokenStream tokens, ParserRuleContext ruleDefNode) {
  Token stop = ruleDefNode.getStop();
  Token semi = stop;
  TerminalNode colonNode = ruleDefNode.getToken(ANTLRv4Parser.COLON, 0);
  Token colon = colonNode.getSymbol();
  Token beforeSemi = tokens.get(stop.getTokenIndex()-1);
  Token afterColon = tokens.get(colon.getTokenIndex()+1);
  // trim whitespace/comments before / after rule text
  List<Token> ignoreBefore = tokens.getHiddenTokensToRight(colon.getTokenIndex());
  List<Token> ignoreAfter = tokens.getHiddenTokensToLeft(semi.getTokenIndex());
  Token textStart = afterColon;
  Token textStop = beforeSemi;
  if ( ignoreBefore!=null ) {
    Token lastWSAfterColon = ignoreBefore.get(ignoreBefore.size()-1);
    textStart = tokens.get(lastWSAfterColon.getTokenIndex()+1);
  }
  if ( ignoreAfter!=null ) {
    int firstWSAtEndOfRule = ignoreAfter.get(0).getTokenIndex()-1;
    textStop = tokens.get(firstWSAtEndOfRule); // stop before 1st ignore token at end
  }
  return tokens.getText(textStart, textStop);
}

private void addIgnoredChars(ParserRuleContext ctx, NodeBuilder nodeBuilder) {
  Token start = ctx.getStart();
  int tokenStartIndex = start.getTokenIndex();
  List<Token> leftChannel = tokens.getHiddenTokensToLeft(tokenStartIndex, CHANNEL_IGNORED_CHARS);
  List<IgnoredChar> ignoredCharsLeft = mapTokenToIgnoredChar(leftChannel);
  Token stop = ctx.getStop();
  int tokenStopIndex = stop.getTokenIndex();
  List<Token> rightChannel = tokens.getHiddenTokensToRight(tokenStopIndex, CHANNEL_IGNORED_CHARS);
  List<IgnoredChar> ignoredCharsRight = mapTokenToIgnoredChar(rightChannel);
  nodeBuilder.ignoredChars(new IgnoredChars(ignoredCharsLeft, ignoredCharsRight));
}