Adding upstream version 1.16.10.upstream/1.16.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 915 insertions, 0 deletions

diff --git a/src/text/scanner/scanner_test.go b/src/text/scanner/scanner_test.go
new file mode 100644
index 0000000..fe39d30
--- /dev/null
+++ b/src/text/scanner/scanner_test.go
@@ -0,0 +1,915 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package scanner
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+// A StringReader delivers its data one string segment at a time via Read.
+type StringReader struct {
+	data []string
+	step int
+}
+
+func (r *StringReader) Read(p []byte) (n int, err error) {
+	if r.step < len(r.data) {
+		s := r.data[r.step]
+		n = copy(p, s)
+		r.step++
+	} else {
+		err = io.EOF
+	}
+	return
+}
+
+func readRuneSegments(t *testing.T, segments []string) {
+	got := ""
+	want := strings.Join(segments, "")
+	s := new(Scanner).Init(&StringReader{data: segments})
+	for {
+		ch := s.Next()
+		if ch == EOF {
+			break
+		}
+		got += string(ch)
+	}
+	if got != want {
+		t.Errorf("segments=%v got=%s want=%s", segments, got, want)
+	}
+}
+
+var segmentList = [][]string{
+	{},
+	{""},
+	{"日", "本語"},
+	{"\u65e5", "\u672c", "\u8a9e"},
+	{"\U000065e5", " ", "\U0000672c", "\U00008a9e"},
+	{"\xe6", "\x97\xa5\xe6", "\x9c\xac\xe8\xaa\x9e"},
+	{"Hello", ", ", "World", "!"},
+	{"Hello", ", ", "", "World", "!"},
+}
+
+func TestNext(t *testing.T) {
+	for _, s := range segmentList {
+		readRuneSegments(t, s)
+	}
+}
+
+type token struct {
+	tok  rune
+	text string
+}
+
+var f100 = "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+
+var tokenList = []token{
+	{Comment, "// line comments"},
+	{Comment, "//"},
+	{Comment, "////"},
+	{Comment, "// comment"},
+	{Comment, "// /* comment */"},
+	{Comment, "// // comment //"},
+	{Comment, "//" + f100},
+
+	{Comment, "// general comments"},
+	{Comment, "/**/"},
+	{Comment, "/***/"},
+	{Comment, "/* comment */"},
+	{Comment, "/* // comment */"},
+	{Comment, "/* /* comment */"},
+	{Comment, "/*\n comment\n*/"},
+	{Comment, "/*" + f100 + "*/"},
+
+	{Comment, "// identifiers"},
+	{Ident, "a"},
+	{Ident, "a0"},
+	{Ident, "foobar"},
+	{Ident, "abc123"},
+	{Ident, "LGTM"},
+	{Ident, "_"},
+	{Ident, "_abc123"},
+	{Ident, "abc123_"},
+	{Ident, "_abc_123_"},
+	{Ident, "_äöü"},
+	{Ident, "_本"},
+	{Ident, "äöü"},
+	{Ident, "本"},
+	{Ident, "a۰۱۸"},
+	{Ident, "foo६४"},
+	{Ident, "bar９８７６"},
+	{Ident, f100},
+
+	{Comment, "// decimal ints"},
+	{Int, "0"},
+	{Int, "1"},
+	{Int, "9"},
+	{Int, "42"},
+	{Int, "1234567890"},
+
+	{Comment, "// octal ints"},
+	{Int, "00"},
+	{Int, "01"},
+	{Int, "07"},
+	{Int, "042"},
+	{Int, "01234567"},
+
+	{Comment, "// hexadecimal ints"},
+	{Int, "0x0"},
+	{Int, "0x1"},
+	{Int, "0xf"},
+	{Int, "0x42"},
+	{Int, "0x123456789abcDEF"},
+	{Int, "0x" + f100},
+	{Int, "0X0"},
+	{Int, "0X1"},
+	{Int, "0XF"},
+	{Int, "0X42"},
+	{Int, "0X123456789abcDEF"},
+	{Int, "0X" + f100},
+
+	{Comment, "// floats"},
+	{Float, "0."},
+	{Float, "1."},
+	{Float, "42."},
+	{Float, "01234567890."},
+	{Float, ".0"},
+	{Float, ".1"},
+	{Float, ".42"},
+	{Float, ".0123456789"},
+	{Float, "0.0"},
+	{Float, "1.0"},
+	{Float, "42.0"},
+	{Float, "01234567890.0"},
+	{Float, "0e0"},
+	{Float, "1e0"},
+	{Float, "42e0"},
+	{Float, "01234567890e0"},
+	{Float, "0E0"},
+	{Float, "1E0"},
+	{Float, "42E0"},
+	{Float, "01234567890E0"},
+	{Float, "0e+10"},
+	{Float, "1e-10"},
+	{Float, "42e+10"},
+	{Float, "01234567890e-10"},
+	{Float, "0E+10"},
+	{Float, "1E-10"},
+	{Float, "42E+10"},
+	{Float, "01234567890E-10"},
+
+	{Comment, "// chars"},
+	{Char, `' '`},
+	{Char, `'a'`},
+	{Char, `'本'`},
+	{Char, `'\a'`},
+	{Char, `'\b'`},
+	{Char, `'\f'`},
+	{Char, `'\n'`},
+	{Char, `'\r'`},
+	{Char, `'\t'`},
+	{Char, `'\v'`},
+	{Char, `'\''`},
+	{Char, `'\000'`},
+	{Char, `'\777'`},
+	{Char, `'\x00'`},
+	{Char, `'\xff'`},
+	{Char, `'\u0000'`},
+	{Char, `'\ufA16'`},
+	{Char, `'\U00000000'`},
+	{Char, `'\U0000ffAB'`},
+
+	{Comment, "// strings"},
+	{String, `" "`},
+	{String, `"a"`},
+	{String, `"本"`},
+	{String, `"\a"`},
+	{String, `"\b"`},
+	{String, `"\f"`},
+	{String, `"\n"`},
+	{String, `"\r"`},
+	{String, `"\t"`},
+	{String, `"\v"`},
+	{String, `"\""`},
+	{String, `"\000"`},
+	{String, `"\777"`},
+	{String, `"\x00"`},
+	{String, `"\xff"`},
+	{String, `"\u0000"`},
+	{String, `"\ufA16"`},
+	{String, `"\U00000000"`},
+	{String, `"\U0000ffAB"`},
+	{String, `"` + f100 + `"`},
+
+	{Comment, "// raw strings"},
+	{RawString, "``"},
+	{RawString, "`\\`"},
+	{RawString, "`" + "\n\n/* foobar */\n\n" + "`"},
+	{RawString, "`" + f100 + "`"},
+
+	{Comment, "// individual characters"},
+	// NUL character is not allowed
+	{'\x01', "\x01"},
+	{' ' - 1, string(' ' - 1)},
+	{'+', "+"},
+	{'/', "/"},
+	{'.', "."},
+	{'~', "~"},
+	{'(', "("},
+}
+
+func makeSource(pattern string) *bytes.Buffer {
+	var buf bytes.Buffer
+	for _, k := range tokenList {
+		fmt.Fprintf(&buf, pattern, k.text)
+	}
+	return &buf
+}
+
+func checkTok(t *testing.T, s *Scanner, line int, got, want rune, text string) {
+	if got != want {
+		t.Fatalf("tok = %s, want %s for %q", TokenString(got), TokenString(want), text)
+	}
+	if s.Line != line {
+		t.Errorf("line = %d, want %d for %q", s.Line, line, text)
+	}
+	stext := s.TokenText()
+	if stext != text {
+		t.Errorf("text = %q, want %q", stext, text)
+	} else {
+		// check idempotency of TokenText() call
+		stext = s.TokenText()
+		if stext != text {
+			t.Errorf("text = %q, want %q (idempotency check)", stext, text)
+		}
+	}
+}
+
+func checkTokErr(t *testing.T, s *Scanner, line int, want rune, text string) {
+	prevCount := s.ErrorCount
+	checkTok(t, s, line, s.Scan(), want, text)
+	if s.ErrorCount != prevCount+1 {
+		t.Fatalf("want error for %q", text)
+	}
+}
+
+func countNewlines(s string) int {
+	n := 0
+	for _, ch := range s {
+		if ch == '\n' {
+			n++
+		}
+	}
+	return n
+}
+
+func testScan(t *testing.T, mode uint) {
+	s := new(Scanner).Init(makeSource(" \t%s\n"))
+	s.Mode = mode
+	tok := s.Scan()
+	line := 1
+	for _, k := range tokenList {
+		if mode&SkipComments == 0 || k.tok != Comment {
+			checkTok(t, s, line, tok, k.tok, k.text)
+			tok = s.Scan()
+		}
+		line += countNewlines(k.text) + 1 // each token is on a new line
+	}
+	checkTok(t, s, line, tok, EOF, "")
+}
+
+func TestScan(t *testing.T) {
+	testScan(t, GoTokens)
+	testScan(t, GoTokens&^SkipComments)
+}
+
+func TestInvalidExponent(t *testing.T) {
+	const src = "1.5e 1.5E 1e+ 1e- 1.5z"
+	s := new(Scanner).Init(strings.NewReader(src))
+	s.Error = func(s *Scanner, msg string) {
+		const want = "exponent has no digits"
+		if msg != want {
+			t.Errorf("%s: got error %q; want %q", s.TokenText(), msg, want)
+		}
+	}
+	checkTokErr(t, s, 1, Float, "1.5e")
+	checkTokErr(t, s, 1, Float, "1.5E")
+	checkTokErr(t, s, 1, Float, "1e+")
+	checkTokErr(t, s, 1, Float, "1e-")
+	checkTok(t, s, 1, s.Scan(), Float, "1.5")
+	checkTok(t, s, 1, s.Scan(), Ident, "z")
+	checkTok(t, s, 1, s.Scan(), EOF, "")
+	if s.ErrorCount != 4 {
+		t.Errorf("%d errors, want 4", s.ErrorCount)
+	}
+}
+
+func TestPosition(t *testing.T) {
+	src := makeSource("\t\t\t\t%s\n")
+	s := new(Scanner).Init(src)
+	s.Mode = GoTokens &^ SkipComments
+	s.Scan()
+	pos := Position{"", 4, 1, 5}
+	for _, k := range tokenList {
+		if s.Offset != pos.Offset {
+			t.Errorf("offset = %d, want %d for %q", s.Offset, pos.Offset, k.text)
+		}
+		if s.Line != pos.Line {
+			t.Errorf("line = %d, want %d for %q", s.Line, pos.Line, k.text)
+		}
+		if s.Column != pos.Column {
+			t.Errorf("column = %d, want %d for %q", s.Column, pos.Column, k.text)
+		}
+		pos.Offset += 4 + len(k.text) + 1     // 4 tabs + token bytes + newline
+		pos.Line += countNewlines(k.text) + 1 // each token is on a new line
+		s.Scan()
+	}
+	// make sure there were no token-internal errors reported by scanner
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+}
+
+func TestScanZeroMode(t *testing.T) {
+	src := makeSource("%s\n")
+	str := src.String()
+	s := new(Scanner).Init(src)
+	s.Mode = 0       // don't recognize any token classes
+	s.Whitespace = 0 // don't skip any whitespace
+	tok := s.Scan()
+	for i, ch := range str {
+		if tok != ch {
+			t.Fatalf("%d. tok = %s, want %s", i, TokenString(tok), TokenString(ch))
+		}
+		tok = s.Scan()
+	}
+	if tok != EOF {
+		t.Fatalf("tok = %s, want EOF", TokenString(tok))
+	}
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+}
+
+func testScanSelectedMode(t *testing.T, mode uint, class rune) {
+	src := makeSource("%s\n")
+	s := new(Scanner).Init(src)
+	s.Mode = mode
+	tok := s.Scan()
+	for tok != EOF {
+		if tok < 0 && tok != class {
+			t.Fatalf("tok = %s, want %s", TokenString(tok), TokenString(class))
+		}
+		tok = s.Scan()
+	}
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+}
+
+func TestScanSelectedMask(t *testing.T) {
+	testScanSelectedMode(t, 0, 0)
+	testScanSelectedMode(t, ScanIdents, Ident)
+	// Don't test ScanInts and ScanNumbers since some parts of
+	// the floats in the source look like (invalid) octal ints
+	// and ScanNumbers may return either Int or Float.
+	testScanSelectedMode(t, ScanChars, Char)
+	testScanSelectedMode(t, ScanStrings, String)
+	testScanSelectedMode(t, SkipComments, 0)
+	testScanSelectedMode(t, ScanComments, Comment)
+}
+
+func TestScanCustomIdent(t *testing.T) {
+	const src = "faab12345 a12b123 a12 3b"
+	s := new(Scanner).Init(strings.NewReader(src))
+	// ident = ( 'a' | 'b' ) { digit } .
+	// digit = '0' .. '3' .
+	// with a maximum length of 4
+	s.IsIdentRune = func(ch rune, i int) bool {
+		return i == 0 && (ch == 'a' || ch == 'b') || 0 < i && i < 4 && '0' <= ch && ch <= '3'
+	}
+	checkTok(t, s, 1, s.Scan(), 'f', "f")
+	checkTok(t, s, 1, s.Scan(), Ident, "a")
+	checkTok(t, s, 1, s.Scan(), Ident, "a")
+	checkTok(t, s, 1, s.Scan(), Ident, "b123")
+	checkTok(t, s, 1, s.Scan(), Int, "45")
+	checkTok(t, s, 1, s.Scan(), Ident, "a12")
+	checkTok(t, s, 1, s.Scan(), Ident, "b123")
+	checkTok(t, s, 1, s.Scan(), Ident, "a12")
+	checkTok(t, s, 1, s.Scan(), Int, "3")
+	checkTok(t, s, 1, s.Scan(), Ident, "b")
+	checkTok(t, s, 1, s.Scan(), EOF, "")
+}
+
+func TestScanNext(t *testing.T) {
+	const BOM = '\uFEFF'
+	BOMs := string(BOM)
+	s := new(Scanner).Init(strings.NewReader(BOMs + "if a == bcd /* com" + BOMs + "ment */ {\n\ta += c\n}" + BOMs + "// line comment ending in eof"))
+	checkTok(t, s, 1, s.Scan(), Ident, "if") // the first BOM is ignored
+	checkTok(t, s, 1, s.Scan(), Ident, "a")
+	checkTok(t, s, 1, s.Scan(), '=', "=")
+	checkTok(t, s, 0, s.Next(), '=', "")
+	checkTok(t, s, 0, s.Next(), ' ', "")
+	checkTok(t, s, 0, s.Next(), 'b', "")
+	checkTok(t, s, 1, s.Scan(), Ident, "cd")
+	checkTok(t, s, 1, s.Scan(), '{', "{")
+	checkTok(t, s, 2, s.Scan(), Ident, "a")
+	checkTok(t, s, 2, s.Scan(), '+', "+")
+	checkTok(t, s, 0, s.Next(), '=', "")
+	checkTok(t, s, 2, s.Scan(), Ident, "c")
+	checkTok(t, s, 3, s.Scan(), '}', "}")
+	checkTok(t, s, 3, s.Scan(), BOM, BOMs)
+	checkTok(t, s, 3, s.Scan(), -1, "")
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+}
+
+func TestScanWhitespace(t *testing.T) {
+	var buf bytes.Buffer
+	var ws uint64
+	// start at 1, NUL character is not allowed
+	for ch := byte(1); ch < ' '; ch++ {
+		buf.WriteByte(ch)
+		ws |= 1 << ch
+	}
+	const orig = 'x'
+	buf.WriteByte(orig)
+
+	s := new(Scanner).Init(&buf)
+	s.Mode = 0
+	s.Whitespace = ws
+	tok := s.Scan()
+	if tok != orig {
+		t.Errorf("tok = %s, want %s", TokenString(tok), TokenString(orig))
+	}
+}
+
+func testError(t *testing.T, src, pos, msg string, tok rune) {
+	s := new(Scanner).Init(strings.NewReader(src))
+	errorCalled := false
+	s.Error = func(s *Scanner, m string) {
+		if !errorCalled {
+			// only look at first error
+			if p := s.Pos().String(); p != pos {
+				t.Errorf("pos = %q, want %q for %q", p, pos, src)
+			}
+			if m != msg {
+				t.Errorf("msg = %q, want %q for %q", m, msg, src)
+			}
+			errorCalled = true
+		}
+	}
+	tk := s.Scan()
+	if tk != tok {
+		t.Errorf("tok = %s, want %s for %q", TokenString(tk), TokenString(tok), src)
+	}
+	if !errorCalled {
+		t.Errorf("error handler not called for %q", src)
+	}
+	if s.ErrorCount == 0 {
+		t.Errorf("count = %d, want > 0 for %q", s.ErrorCount, src)
+	}
+}
+
+func TestError(t *testing.T) {
+	testError(t, "\x00", "<input>:1:1", "invalid character NUL", 0)
+	testError(t, "\x80", "<input>:1:1", "invalid UTF-8 encoding", utf8.RuneError)
+	testError(t, "\xff", "<input>:1:1", "invalid UTF-8 encoding", utf8.RuneError)
+
+	testError(t, "a\x00", "<input>:1:2", "invalid character NUL", Ident)
+	testError(t, "ab\x80", "<input>:1:3", "invalid UTF-8 encoding", Ident)
+	testError(t, "abc\xff", "<input>:1:4", "invalid UTF-8 encoding", Ident)
+
+	testError(t, `"a`+"\x00", "<input>:1:3", "invalid character NUL", String)
+	testError(t, `"ab`+"\x80", "<input>:1:4", "invalid UTF-8 encoding", String)
+	testError(t, `"abc`+"\xff", "<input>:1:5", "invalid UTF-8 encoding", String)
+
+	testError(t, "`a"+"\x00", "<input>:1:3", "invalid character NUL", RawString)
+	testError(t, "`ab"+"\x80", "<input>:1:4", "invalid UTF-8 encoding", RawString)
+	testError(t, "`abc"+"\xff", "<input>:1:5", "invalid UTF-8 encoding", RawString)
+
+	testError(t, `'\"'`, "<input>:1:3", "invalid char escape", Char)
+	testError(t, `"\'"`, "<input>:1:3", "invalid char escape", String)
+
+	testError(t, `01238`, "<input>:1:6", "invalid digit '8' in octal literal", Int)
+	testError(t, `01238123`, "<input>:1:9", "invalid digit '8' in octal literal", Int)
+	testError(t, `0x`, "<input>:1:3", "hexadecimal literal has no digits", Int)
+	testError(t, `0xg`, "<input>:1:3", "hexadecimal literal has no digits", Int)
+	testError(t, `'aa'`, "<input>:1:4", "invalid char literal", Char)
+	testError(t, `1.5e`, "<input>:1:5", "exponent has no digits", Float)
+	testError(t, `1.5E`, "<input>:1:5", "exponent has no digits", Float)
+	testError(t, `1.5e+`, "<input>:1:6", "exponent has no digits", Float)
+	testError(t, `1.5e-`, "<input>:1:6", "exponent has no digits", Float)
+
+	testError(t, `'`, "<input>:1:2", "literal not terminated", Char)
+	testError(t, `'`+"\n", "<input>:1:2", "literal not terminated", Char)
+	testError(t, `"abc`, "<input>:1:5", "literal not terminated", String)
+	testError(t, `"abc`+"\n", "<input>:1:5", "literal not terminated", String)
+	testError(t, "`abc\n", "<input>:2:1", "literal not terminated", RawString)
+	testError(t, `/*/`, "<input>:1:4", "comment not terminated", EOF)
+}
+
+// An errReader returns (0, err) where err is not io.EOF.
+type errReader struct{}
+
+func (errReader) Read(b []byte) (int, error) {
+	return 0, io.ErrNoProgress // some error that is not io.EOF
+}
+
+func TestIOError(t *testing.T) {
+	s := new(Scanner).Init(errReader{})
+	errorCalled := false
+	s.Error = func(s *Scanner, msg string) {
+		if !errorCalled {
+			if want := io.ErrNoProgress.Error(); msg != want {
+				t.Errorf("msg = %q, want %q", msg, want)
+			}
+			errorCalled = true
+		}
+	}
+	tok := s.Scan()
+	if tok != EOF {
+		t.Errorf("tok = %s, want EOF", TokenString(tok))
+	}
+	if !errorCalled {
+		t.Errorf("error handler not called")
+	}
+}
+
+func checkPos(t *testing.T, got, want Position) {
+	if got.Offset != want.Offset || got.Line != want.Line || got.Column != want.Column {
+		t.Errorf("got offset, line, column = %d, %d, %d; want %d, %d, %d",
+			got.Offset, got.Line, got.Column, want.Offset, want.Line, want.Column)
+	}
+}
+
+func checkNextPos(t *testing.T, s *Scanner, offset, line, column int, char rune) {
+	if ch := s.Next(); ch != char {
+		t.Errorf("ch = %s, want %s", TokenString(ch), TokenString(char))
+	}
+	want := Position{Offset: offset, Line: line, Column: column}
+	checkPos(t, s.Pos(), want)
+}
+
+func checkScanPos(t *testing.T, s *Scanner, offset, line, column int, char rune) {
+	want := Position{Offset: offset, Line: line, Column: column}
+	checkPos(t, s.Pos(), want)
+	if ch := s.Scan(); ch != char {
+		t.Errorf("ch = %s, want %s", TokenString(ch), TokenString(char))
+		if string(ch) != s.TokenText() {
+			t.Errorf("tok = %q, want %q", s.TokenText(), string(ch))
+		}
+	}
+	checkPos(t, s.Position, want)
+}
+
+func TestPos(t *testing.T) {
+	// corner case: empty source
+	s := new(Scanner).Init(strings.NewReader(""))
+	checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1})
+	s.Peek() // peek doesn't affect the position
+	checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1})
+
+	// corner case: source with only a newline
+	s = new(Scanner).Init(strings.NewReader("\n"))
+	checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1})
+	checkNextPos(t, s, 1, 2, 1, '\n')
+	// after EOF position doesn't change
+	for i := 10; i > 0; i-- {
+		checkScanPos(t, s, 1, 2, 1, EOF)
+	}
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+
+	// corner case: source with only a single character
+	s = new(Scanner).Init(strings.NewReader("本"))
+	checkPos(t, s.Pos(), Position{Offset: 0, Line: 1, Column: 1})
+	checkNextPos(t, s, 3, 1, 2, '本')
+	// after EOF position doesn't change
+	for i := 10; i > 0; i-- {
+		checkScanPos(t, s, 3, 1, 2, EOF)
+	}
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+
+	// positions after calling Next
+	s = new(Scanner).Init(strings.NewReader("  foo६४  \n\n本語\n"))
+	checkNextPos(t, s, 1, 1, 2, ' ')
+	s.Peek() // peek doesn't affect the position
+	checkNextPos(t, s, 2, 1, 3, ' ')
+	checkNextPos(t, s, 3, 1, 4, 'f')
+	checkNextPos(t, s, 4, 1, 5, 'o')
+	checkNextPos(t, s, 5, 1, 6, 'o')
+	checkNextPos(t, s, 8, 1, 7, '६')
+	checkNextPos(t, s, 11, 1, 8, '४')
+	checkNextPos(t, s, 12, 1, 9, ' ')
+	checkNextPos(t, s, 13, 1, 10, ' ')
+	checkNextPos(t, s, 14, 2, 1, '\n')
+	checkNextPos(t, s, 15, 3, 1, '\n')
+	checkNextPos(t, s, 18, 3, 2, '本')
+	checkNextPos(t, s, 21, 3, 3, '語')
+	checkNextPos(t, s, 22, 4, 1, '\n')
+	// after EOF position doesn't change
+	for i := 10; i > 0; i-- {
+		checkScanPos(t, s, 22, 4, 1, EOF)
+	}
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+
+	// positions after calling Scan
+	s = new(Scanner).Init(strings.NewReader("abc\n本語\n\nx"))
+	s.Mode = 0
+	s.Whitespace = 0
+	checkScanPos(t, s, 0, 1, 1, 'a')
+	s.Peek() // peek doesn't affect the position
+	checkScanPos(t, s, 1, 1, 2, 'b')
+	checkScanPos(t, s, 2, 1, 3, 'c')
+	checkScanPos(t, s, 3, 1, 4, '\n')
+	checkScanPos(t, s, 4, 2, 1, '本')
+	checkScanPos(t, s, 7, 2, 2, '語')
+	checkScanPos(t, s, 10, 2, 3, '\n')
+	checkScanPos(t, s, 11, 3, 1, '\n')
+	checkScanPos(t, s, 12, 4, 1, 'x')
+	// after EOF position doesn't change
+	for i := 10; i > 0; i-- {
+		checkScanPos(t, s, 13, 4, 2, EOF)
+	}
+	if s.ErrorCount != 0 {
+		t.Errorf("%d errors", s.ErrorCount)
+	}
+}
+
+type countReader int
+
+func (r *countReader) Read([]byte) (int, error) {
+	*r++
+	return 0, io.EOF
+}
+
+func TestNextEOFHandling(t *testing.T) {
+	var r countReader
+
+	// corner case: empty source
+	s := new(Scanner).Init(&r)
+
+	tok := s.Next()
+	if tok != EOF {
+		t.Error("1) EOF not reported")
+	}
+
+	tok = s.Peek()
+	if tok != EOF {
+		t.Error("2) EOF not reported")
+	}
+
+	if r != 1 {
+		t.Errorf("scanner called Read %d times, not once", r)
+	}
+}
+
+func TestScanEOFHandling(t *testing.T) {
+	var r countReader
+
+	// corner case: empty source
+	s := new(Scanner).Init(&r)
+
+	tok := s.Scan()
+	if tok != EOF {
+		t.Error("1) EOF not reported")
+	}
+
+	tok = s.Peek()
+	if tok != EOF {
+		t.Error("2) EOF not reported")
+	}
+
+	if r != 1 {
+		t.Errorf("scanner called Read %d times, not once", r)
+	}
+}
+
+func TestIssue29723(t *testing.T) {
+	s := new(Scanner).Init(strings.NewReader(`x "`))
+	s.Error = func(s *Scanner, _ string) {
+		got := s.TokenText() // this call shouldn't panic
+		const want = `"`
+		if got != want {
+			t.Errorf("got %q; want %q", got, want)
+		}
+	}
+	for r := s.Scan(); r != EOF; r = s.Scan() {
+	}
+}
+
+func TestNumbers(t *testing.T) {
+	for _, test := range []struct {
+		tok              rune
+		src, tokens, err string
+	}{
+		// binaries
+		{Int, "0b0", "0b0", ""},
+		{Int, "0b1010", "0b1010", ""},
+		{Int, "0B1110", "0B1110", ""},
+
+		{Int, "0b", "0b", "binary literal has no digits"},
+		{Int, "0b0190", "0b0190", "invalid digit '9' in binary literal"},
+		{Int, "0b01a0", "0b01 a0", ""}, // only accept 0-9
+
+		// binary floats (invalid)
+		{Float, "0b.", "0b.", "invalid radix point in binary literal"},
+		{Float, "0b.1", "0b.1", "invalid radix point in binary literal"},
+		{Float, "0b1.0", "0b1.0", "invalid radix point in binary literal"},
+		{Float, "0b1e10", "0b1e10", "'e' exponent requires decimal mantissa"},
+		{Float, "0b1P-1", "0b1P-1", "'P' exponent requires hexadecimal mantissa"},
+
+		// octals
+		{Int, "0o0", "0o0", ""},
+		{Int, "0o1234", "0o1234", ""},
+		{Int, "0O1234", "0O1234", ""},
+
+		{Int, "0o", "0o", "octal literal has no digits"},
+		{Int, "0o8123", "0o8123", "invalid digit '8' in octal literal"},
+		{Int, "0o1293", "0o1293", "invalid digit '9' in octal literal"},
+		{Int, "0o12a3", "0o12 a3", ""}, // only accept 0-9
+
+		// octal floats (invalid)
+		{Float, "0o.", "0o.", "invalid radix point in octal literal"},
+		{Float, "0o.2", "0o.2", "invalid radix point in octal literal"},
+		{Float, "0o1.2", "0o1.2", "invalid radix point in octal literal"},
+		{Float, "0o1E+2", "0o1E+2", "'E' exponent requires decimal mantissa"},
+		{Float, "0o1p10", "0o1p10", "'p' exponent requires hexadecimal mantissa"},
+
+		// 0-octals
+		{Int, "0", "0", ""},
+		{Int, "0123", "0123", ""},
+
+		{Int, "08123", "08123", "invalid digit '8' in octal literal"},
+		{Int, "01293", "01293", "invalid digit '9' in octal literal"},
+		{Int, "0F.", "0 F .", ""}, // only accept 0-9
+		{Int, "0123F.", "0123 F .", ""},
+		{Int, "0123456x", "0123456 x", ""},
+
+		// decimals
+		{Int, "1", "1", ""},
+		{Int, "1234", "1234", ""},
+
+		{Int, "1f", "1 f", ""}, // only accept 0-9
+
+		// decimal floats
+		{Float, "0.", "0.", ""},
+		{Float, "123.", "123.", ""},
+		{Float, "0123.", "0123.", ""},
+
+		{Float, ".0", ".0", ""},
+		{Float, ".123", ".123", ""},
+		{Float, ".0123", ".0123", ""},
+
+		{Float, "0.0", "0.0", ""},
+		{Float, "123.123", "123.123", ""},
+		{Float, "0123.0123", "0123.0123", ""},
+
+		{Float, "0e0", "0e0", ""},
+		{Float, "123e+0", "123e+0", ""},
+		{Float, "0123E-1", "0123E-1", ""},
+
+		{Float, "0.e+1", "0.e+1", ""},
+		{Float, "123.E-10", "123.E-10", ""},
+		{Float, "0123.e123", "0123.e123", ""},
+
+		{Float, ".0e-1", ".0e-1", ""},
+		{Float, ".123E+10", ".123E+10", ""},
+		{Float, ".0123E123", ".0123E123", ""},
+
+		{Float, "0.0e1", "0.0e1", ""},
+		{Float, "123.123E-10", "123.123E-10", ""},
+		{Float, "0123.0123e+456", "0123.0123e+456", ""},
+
+		{Float, "0e", "0e", "exponent has no digits"},
+		{Float, "0E+", "0E+", "exponent has no digits"},
+		{Float, "1e+f", "1e+ f", "exponent has no digits"},
+		{Float, "0p0", "0p0", "'p' exponent requires hexadecimal mantissa"},
+		{Float, "1.0P-1", "1.0P-1", "'P' exponent requires hexadecimal mantissa"},
+
+		// hexadecimals
+		{Int, "0x0", "0x0", ""},
+		{Int, "0x1234", "0x1234", ""},
+		{Int, "0xcafef00d", "0xcafef00d", ""},
+		{Int, "0XCAFEF00D", "0XCAFEF00D", ""},
+
+		{Int, "0x", "0x", "hexadecimal literal has no digits"},
+		{Int, "0x1g", "0x1 g", ""},
+
+		// hexadecimal floats
+		{Float, "0x0p0", "0x0p0", ""},
+		{Float, "0x12efp-123", "0x12efp-123", ""},
+		{Float, "0xABCD.p+0", "0xABCD.p+0", ""},
+		{Float, "0x.0189P-0", "0x.0189P-0", ""},
+		{Float, "0x1.ffffp+1023", "0x1.ffffp+1023", ""},
+
+		{Float, "0x.", "0x.", "hexadecimal literal has no digits"},
+		{Float, "0x0.", "0x0.", "hexadecimal mantissa requires a 'p' exponent"},
+		{Float, "0x.0", "0x.0", "hexadecimal mantissa requires a 'p' exponent"},
+		{Float, "0x1.1", "0x1.1", "hexadecimal mantissa requires a 'p' exponent"},
+		{Float, "0x1.1e0", "0x1.1e0", "hexadecimal mantissa requires a 'p' exponent"},
+		{Float, "0x1.2gp1a", "0x1.2 gp1a", "hexadecimal mantissa requires a 'p' exponent"},
+		{Float, "0x0p", "0x0p", "exponent has no digits"},
+		{Float, "0xeP-", "0xeP-", "exponent has no digits"},
+		{Float, "0x1234PAB", "0x1234P AB", "exponent has no digits"},
+		{Float, "0x1.2p1a", "0x1.2p1 a", ""},
+
+		// separators
+		{Int, "0b_1000_0001", "0b_1000_0001", ""},
+		{Int, "0o_600", "0o_600", ""},
+		{Int, "0_466", "0_466", ""},
+		{Int, "1_000", "1_000", ""},
+		{Float, "1_000.000_1", "1_000.000_1", ""},
+		{Int, "0x_f00d", "0x_f00d", ""},
+		{Float, "0x_f00d.0p1_2", "0x_f00d.0p1_2", ""},
+
+		{Int, "0b__1000", "0b__1000", "'_' must separate successive digits"},
+		{Int, "0o60___0", "0o60___0", "'_' must separate successive digits"},
+		{Int, "0466_", "0466_", "'_' must separate successive digits"},
+		{Float, "1_.", "1_.", "'_' must separate successive digits"},
+		{Float, "0._1", "0._1", "'_' must separate successive digits"},
+		{Float, "2.7_e0", "2.7_e0", "'_' must separate successive digits"},
+		{Int, "0x___0", "0x___0", "'_' must separate successive digits"},
+		{Float, "0x1.0_p0", "0x1.0_p0", "'_' must separate successive digits"},
+	} {
+		s := new(Scanner).Init(strings.NewReader(test.src))
+		var err string
+		s.Error = func(s *Scanner, msg string) {
+			if err == "" {
+				err = msg
+			}
+		}
+
+		for i, want := range strings.Split(test.tokens, " ") {
+			err = ""
+			tok := s.Scan()
+			lit := s.TokenText()
+			if i == 0 {
+				if tok != test.tok {
+					t.Errorf("%q: got token %s; want %s", test.src, TokenString(tok), TokenString(test.tok))
+				}
+				if err != test.err {
+					t.Errorf("%q: got error %q; want %q", test.src, err, test.err)
+				}
+			}
+			if lit != want {
+				t.Errorf("%q: got literal %q (%s); want %s", test.src, lit, TokenString(tok), want)
+			}
+		}
+
+		// make sure we read all
+		if tok := s.Scan(); tok != EOF {
+			t.Errorf("%q: got %s; want EOF", test.src, TokenString(tok))
+		}
+	}
+}
+
+func TestIssue30320(t *testing.T) {
+	for _, test := range []struct {
+		in, want string
+		mode     uint
+	}{
+		{"foo01.bar31.xx-0-1-1-0", "01 31 0 1 1 0", ScanInts},
+		{"foo0/12/0/5.67", "0 12 0 5 67", ScanInts},
+		{"xxx1e0yyy", "1 0", ScanInts},
+		{"1_2", "1_2", ScanInts},
+		{"xxx1.0yyy2e3ee", "1 0 2 3", ScanInts},
+		{"xxx1.0yyy2e3ee", "1.0 2e3", ScanFloats},
+	} {
+		got := extractInts(test.in, test.mode)
+		if got != test.want {
+			t.Errorf("%q: got %q; want %q", test.in, got, test.want)
+		}
+	}
+}
+
+func extractInts(t string, mode uint) (res string) {
+	var s Scanner
+	s.Init(strings.NewReader(t))
+	s.Mode = mode
+	for {
+		switch tok := s.Scan(); tok {
+		case Int, Float:
+			if len(res) > 0 {
+				res += " "
+			}
+			res += s.TokenText()
+		case EOF:
+			return
+		}
+	}
+}