int seen;

          @Override
          public boolean processLine(String line) {
            seen++;
            return false;
          }

          @Override
          public Integer getResult() {
            return seen;
          }
        };
    assertEquals(
        "processLine was called more than once",
        1,
        CharStreams.readLines(r, alwaysFalse).intValue());

          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;
            return false;
          }

          @Override
          public Integer getResult() {
            return seen;
          }
        };
    assertEquals(
        "processLine was called more than once",
        1,
        CharStreams.readLines(r, alwaysFalse).intValue());

    List<String> list =
        lines.readLines(
            new LineProcessor<List<String>>() {
              List<String> list = Lists.newArrayList();

              @Override
              public boolean processLine(String line) throws IOException {
                list.add(line);
                return true;
              }

              @Override
              public List<String> getResult() {

    List<String> list =
        lines.readLines(
            new LineProcessor<List<String>>() {
              List<String> list = Lists.newArrayList();

              @Override
              public boolean processLine(String line) throws IOException {
                list.add(line);
                return true;
              }

              @Override
              public List<String> getResult() {

    LineProcessor<List<String>> collect =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override
          public boolean processLine(String line) {
            collector.add(line);
            return true;
          }

          @Override
          public List<String> getResult() {
            return collector;
          }

    checkNotNull(readable);
    checkNotNull(processor);

    LineReader lineReader = new LineReader(readable);
    String line;
    while ((line = lineReader.readLine()) != null) {
      if (!processor.processLine(line)) {
        break;
      }
    }
    return processor.getResult();
  }

  /**
   * Reads and discards data from the given {@code Readable} until the end of the stream is reached.

    LineProcessor<List<String>> collect =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override
          public boolean processLine(String line) {
            collector.add(line);
            return true;
          }

          @Override
          public List<String> getResult() {
            return collector;
          }

    public <T extends @Nullable Object> T readLines(LineProcessor<T> processor) throws IOException {
      Iterator<String> lines = linesIterator();
      while (lines.hasNext()) {
        if (!processor.processLine(lines.next())) {
          break;
        }
      }
      return processor.getResult();
    }

    @Override
    public String toString() {

        .readLines(
            new LineProcessor<List<String>>() {
              final List<String> result = Lists.newArrayList();

              @Override
              public boolean processLine(String line) {
                result.add(line);
                return true;
              }

              @Override
              public List<String> getResult() {
                return result;

func (in *Input) macroName() string {
	// We use the Stack's input method; no macro processing at this stage.
	tok := in.Stack.Next()
	if tok != scanner.Ident {
		in.expectText("expected identifier after # directive")
	}
	// Name is alphanumeric by definition.
	return in.Stack.Text()
}

// #define processing.
func (in *Input) define() {
	name := in.macroName()
	args, tokens := in.macroDefinition(name)