private static final ImmutableMap<Character, String> NO_REPLACEMENTS = ImmutableMap.of();
  private static final ImmutableMap<Character, String> SIMPLE_REPLACEMENTS =
      ImmutableMap.of(
          '\n', "<newline>",
          '\t', "<tab>",
          '&', "<and>");

  public void testSafeRange() throws IOException {
    // Basic escaping of unsafe chars (wrap them in {,}'s)
    CharEscaper wrappingEscaper =

      val length = logMessage.length
      while (i < length) {
        var newline = logMessage.indexOf('\n', i)
        newline = if (newline != -1) newline else length
        do {
          val end = minOf(newline, i + MAX_LOG_LENGTH)
          Log.println(logLevel, tag, logMessage.substring(i, end))
          i = end
        } while (i < newline)
        i++
      }
    }
  }

import (
	"iter"
	"unicode"
	"unicode/utf8"
)

// Lines returns an iterator over the newline-terminated lines in the byte slice s.
// The lines yielded by the iterator include their terminating newlines.
// If s is empty, the iterator yields no lines at all.
// If s does not end in a newline, the final yielded line will not end in a newline.
// It returns a single-use iterator.
func Lines(s []byte) iter.Seq[[]byte] {

// by one mandatory newline. In regular expression notation, it is `\r?\n`.
// The last non-empty line of input will be returned even if it has no
// newline.
func ScanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
	if atEOF && len(data) == 0 {
		return 0, nil, nil
	}
	if i := bytes.IndexByte(data, '\n'); i >= 0 {
		// We have a full newline-terminated line.

		// Test some weird characters over the wire.
		{"foo", "newline\n", testData, false, true},
		{"foo", "newline\t", testData, false, true},
		{"foo", "newline \n", testData, false, true},
		{"foo", "newline$$$\n", testData, false, true},
		{"foo", "newline%%%\n", testData, false, true},
		{"foo", "newline \t % $ & * ^ # @ \n", testData, false, true},

  while (!exhausted()) {
    if (buffer[0] != ' '.code.toByte()) return
    skip(1L)
  }
}

private fun BufferedSource.skipRestOfLine() {
  when (val newline = indexOf('\n'.code.toByte())) {
    -1L -> skip(buffer.size) // Exhaust this source.
    else -> skip(newline + 1)
  }
}

/**
 * Reads lines from `IdnaMappingTable.txt`.
 *

	base *src.PosBase
	line int
	file *os.File // If non-nil, file descriptor to close.
}

func NewTokenizer(name string, r io.Reader, file *os.File) *Tokenizer {
	var s scanner.Scanner
	s.Init(r)
	// Newline is like a semicolon; other space characters are fine.
	s.Whitespace = 1<<'\t' | 1<<'\r' | 1<<' '
	// Don't skip comments: we need to count newlines.
	s.Mode = scanner.ScanChars |
		scanner.ScanFloats |
		scanner.ScanIdents |

The [bytes] package adds several functions that work with iterators:
- [Lines] returns an iterator over the
  newline-terminated lines in the byte slice s.
- [SplitSeq] returns an iterator over
  all substrings of s separated by sep.
- [SplitAfterSeq] returns an iterator
  over substrings of s split after each instance of sep.
- [FieldsSeq] returns an iterator over
  substrings of s split around runs of whitespace characters,
  as defined by unicode.IsSpace.

      with(sink) {
        writeInt(totalRuleBytes)
        for (domain in sortedRules) {
          write(domain).writeByte(NEWLINE)
        }
        writeInt(totalExceptionRuleBytes)
        for (domain in sortedExceptionRules) {
          write(domain).writeByte(NEWLINE)
        }
      }
    }
  }

  private suspend fun writeOutputFile(importResults: ImportResults) =

				acceptArg = false
			default:
				in.Error("bad definition for macro:", name)
			}
		}
	}
	var tokens []Token
	// Scan to newline. Backslashes escape newlines.
	for tok != '\n' {
		if tok == scanner.EOF {
			in.Error("missing newline in definition for macro:", name)
		}
		if tok == '\\' {
			tok = in.Stack.Next()
			if tok != '\n' && tok != '\\' {