go scanner_test 源码
golang scanner_test 代码
文件路径：/src/go/scanner/scanner_test.go
// 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 (
"go/token"
"os"
"path/filepath"
"runtime"
"strings"
"testing"
)
var fset = token.NewFileSet()
const /* class */ (
special = iota
literal
operator
keyword
)
func tokenclass(tok token.Token) int {
switch {
case tok.IsLiteral():
return literal
case tok.IsOperator():
return operator
case tok.IsKeyword():
return keyword
}
return special
}
type elt struct {
tok token.Token
lit string
class int
}
var tokens = []elt{
// Special tokens
{token.COMMENT, "/* a comment */", special},
{token.COMMENT, "// a comment \n", special},
{token.COMMENT, "/*\r*/", special},
{token.COMMENT, "/**\r/*/", special}, // issue 11151
{token.COMMENT, "/**\r\r/*/", special},
{token.COMMENT, "//\r\n", special},
// Identifiers and basic type literals
{token.IDENT, "foobar", literal},
{token.IDENT, "a۰۱۸", literal},
{token.IDENT, "foo६४", literal},
{token.IDENT, "bar９８７６", literal},
{token.IDENT, "ŝ", literal}, // was bug (issue 4000)
{token.IDENT, "ŝfoo", literal}, // was bug (issue 4000)
{token.INT, "0", literal},
{token.INT, "1", literal},
{token.INT, "123456789012345678890", literal},
{token.INT, "01234567", literal},
{token.INT, "0xcafebabe", literal},
{token.FLOAT, "0.", literal},
{token.FLOAT, ".0", literal},
{token.FLOAT, "3.14159265", literal},
{token.FLOAT, "1e0", literal},
{token.FLOAT, "1e+100", literal},
{token.FLOAT, "1e-100", literal},
{token.FLOAT, "2.71828e-1000", literal},
{token.IMAG, "0i", literal},
{token.IMAG, "1i", literal},
{token.IMAG, "012345678901234567889i", literal},
{token.IMAG, "123456789012345678890i", literal},
{token.IMAG, "0.i", literal},
{token.IMAG, ".0i", literal},
{token.IMAG, "3.14159265i", literal},
{token.IMAG, "1e0i", literal},
{token.IMAG, "1e+100i", literal},
{token.IMAG, "1e-100i", literal},
{token.IMAG, "2.71828e-1000i", literal},
{token.CHAR, "'a'", literal},
{token.CHAR, "'\\000'", literal},
{token.CHAR, "'\\xFF'", literal},
{token.CHAR, "'\\uff16'", literal},
{token.CHAR, "'\\U0000ff16'", literal},
{token.STRING, "`foobar`", literal},
{token.STRING, "`" + `foo
bar` +
"`",
literal,
},
{token.STRING, "`\r`", literal},
{token.STRING, "`foo\r\nbar`", literal},
// Operators and delimiters
{token.ADD, "+", operator},
{token.SUB, "-", operator},
{token.MUL, "*", operator},
{token.QUO, "/", operator},
{token.REM, "%", operator},
{token.AND, "&", operator},
{token.OR, "|", operator},
{token.XOR, "^", operator},
{token.SHL, "<<", operator},
{token.SHR, ">>", operator},
{token.AND_NOT, "&^", operator},
{token.ADD_ASSIGN, "+=", operator},
{token.SUB_ASSIGN, "-=", operator},
{token.MUL_ASSIGN, "*=", operator},
{token.QUO_ASSIGN, "/=", operator},
{token.REM_ASSIGN, "%=", operator},
{token.AND_ASSIGN, "&=", operator},
{token.OR_ASSIGN, "|=", operator},
{token.XOR_ASSIGN, "^=", operator},
{token.SHL_ASSIGN, "<<=", operator},
{token.SHR_ASSIGN, ">>=", operator},
{token.AND_NOT_ASSIGN, "&^=", operator},
{token.LAND, "&&", operator},
{token.LOR, "||", operator},
{token.ARROW, "<-", operator},
{token.INC, "++", operator},
{token.DEC, "--", operator},
{token.EQL, "==", operator},
{token.LSS, "<", operator},
{token.GTR, ">", operator},
{token.ASSIGN, "=", operator},
{token.NOT, "!", operator},
{token.NEQ, "!=", operator},
{token.LEQ, "<=", operator},
{token.GEQ, ">=", operator},
{token.DEFINE, ":=", operator},
{token.ELLIPSIS, "...", operator},
{token.LPAREN, "(", operator},
{token.LBRACK, "[", operator},
{token.LBRACE, "{", operator},
{token.COMMA, ",", operator},
{token.PERIOD, ".", operator},
{token.RPAREN, ")", operator},
{token.RBRACK, "]", operator},
{token.RBRACE, "}", operator},
{token.SEMICOLON, ";", operator},
{token.COLON, ":", operator},
{token.TILDE, "~", operator},
// Keywords
{token.BREAK, "break", keyword},
{token.CASE, "case", keyword},
{token.CHAN, "chan", keyword},
{token.CONST, "const", keyword},
{token.CONTINUE, "continue", keyword},
{token.DEFAULT, "default", keyword},
{token.DEFER, "defer", keyword},
{token.ELSE, "else", keyword},
{token.FALLTHROUGH, "fallthrough", keyword},
{token.FOR, "for", keyword},
{token.FUNC, "func", keyword},
{token.GO, "go", keyword},
{token.GOTO, "goto", keyword},
{token.IF, "if", keyword},
{token.IMPORT, "import", keyword},
{token.INTERFACE, "interface", keyword},
{token.MAP, "map", keyword},
{token.PACKAGE, "package", keyword},
{token.RANGE, "range", keyword},
{token.RETURN, "return", keyword},
{token.SELECT, "select", keyword},
{token.STRUCT, "struct", keyword},
{token.SWITCH, "switch", keyword},
{token.TYPE, "type", keyword},
{token.VAR, "var", keyword},
}
const whitespace = " \t \n\n\n" // to separate tokens
var source = func() []byte {
var src []byte
for _, t := range tokens {
src = append(src, t.lit...)
src = append(src, whitespace...)
}
return src
}()
func newlineCount(s string) int {
n := 0
for i := 0; i < len(s); i++ {
if s[i] == '\n' {
n++
}
}
return n
}
func checkPos(t *testing.T, lit string, p token.Pos, expected token.Position) {
pos := fset.Position(p)
// Check cleaned filenames so that we don't have to worry about
// different os.PathSeparator values.
if pos.Filename != expected.Filename && filepath.Clean(pos.Filename) != filepath.Clean(expected.Filename) {
t.Errorf("bad filename for %q: got %s, expected %s", lit, pos.Filename, expected.Filename)
}
if pos.Offset != expected.Offset {
t.Errorf("bad position for %q: got %d, expected %d", lit, pos.Offset, expected.Offset)
}
if pos.Line != expected.Line {
t.Errorf("bad line for %q: got %d, expected %d", lit, pos.Line, expected.Line)
}
if pos.Column != expected.Column {
t.Errorf("bad column for %q: got %d, expected %d", lit, pos.Column, expected.Column)
}
}
// Verify that calling Scan() provides the correct results.
func TestScan(t *testing.T) {
whitespace_linecount := newlineCount(whitespace)
// error handler
eh := func(_ token.Position, msg string) {
t.Errorf("error handler called (msg = %s)", msg)
}
// verify scan
var s Scanner
s.Init(fset.AddFile("", fset.Base(), len(source)), source, eh, ScanComments|dontInsertSemis)
// set up expected position
epos := token.Position{
Filename: "",
Offset: 0,
Line: 1,
Column: 1,
}
index := 0
for {
pos, tok, lit := s.Scan()
// check position
if tok == token.EOF {
// correction for EOF
epos.Line = newlineCount(string(source))
epos.Column = 2
}
checkPos(t, lit, pos, epos)
// check token
e := elt{token.EOF, "", special}
if index < len(tokens) {
e = tokens[index]
index++
}
if tok != e.tok {
t.Errorf("bad token for %q: got %s, expected %s", lit, tok, e.tok)
}
// check token class
if tokenclass(tok) != e.class {
t.Errorf("bad class for %q: got %d, expected %d", lit, tokenclass(tok), e.class)
}
// check literal
elit := ""
switch e.tok {
case token.COMMENT:
// no CRs in comments
elit = string(stripCR([]byte(e.lit), e.lit[1] == '*'))
//-style comment literal doesn't contain newline
if elit[1] == '/' {
elit = elit[0 : len(elit)-1]
}
case token.IDENT:
elit = e.lit
case token.SEMICOLON:
elit = ";"
default:
if e.tok.IsLiteral() {
// no CRs in raw string literals
elit = e.lit
if elit[0] == '`' {
elit = string(stripCR([]byte(elit), false))
}
} else if e.tok.IsKeyword() {
elit = e.lit
}
}
if lit != elit {
t.Errorf("bad literal for %q: got %q, expected %q", lit, lit, elit)
}
if tok == token.EOF {
break
}
// update position
epos.Offset += len(e.lit) + len(whitespace)
epos.Line += newlineCount(e.lit) + whitespace_linecount
}
if s.ErrorCount != 0 {
t.Errorf("found %d errors", s.ErrorCount)
}
}
func TestStripCR(t *testing.T) {
for _, test := range []struct{ have, want string }{
{"//\n", "//\n"},
{"//\r\n", "//\n"},
{"//\r\r\r\n", "//\n"},
{"//\r*\r/\r\n", "//*/\n"},
{"/**/", "/**/"},
{"/*\r/*/", "/*/*/"},
{"/*\r*/", "/**/"},
{"/**\r/*/", "/**\r/*/"},
{"/*\r/\r*\r/*/", "/*/*\r/*/"},
{"/*\r\r\r\r*/", "/**/"},
} {
got := string(stripCR([]byte(test.have), len(test.have) >= 2 && test.have[1] == '*'))
if got != test.want {
t.Errorf("stripCR(%q) = %q; want %q", test.have, got, test.want)
}
}
}
func checkSemi(t *testing.T, line string, mode Mode) {
var S Scanner
file := fset.AddFile("TestSemis", fset.Base(), len(line))
S.Init(file, []byte(line), nil, mode)
pos, tok, lit := S.Scan()
for tok != token.EOF {
if tok == token.ILLEGAL {
// the illegal token literal indicates what
// kind of semicolon literal to expect
semiLit := "\n"
if lit[0] == '#' {
semiLit = ";"
}
// next token must be a semicolon
semiPos := file.Position(pos)
semiPos.Offset++
semiPos.Column++
pos, tok, lit = S.Scan()
if tok == token.SEMICOLON {
if lit != semiLit {
t.Errorf(`bad literal for %q: got %q, expected %q`, line, lit, semiLit)
}
checkPos(t, line, pos, semiPos)
} else {
t.Errorf("bad token for %q: got %s, expected ;", line, tok)
}
} else if tok == token.SEMICOLON {
t.Errorf("bad token for %q: got ;, expected no ;", line)
}
pos, tok, lit = S.Scan()
}
}
var lines = []string{
// # indicates a semicolon present in the source
// $ indicates an automatically inserted semicolon
"",
"\ufeff#;", // first BOM is ignored
"#;",
"foo$\n",
"123$\n",
"1.2$\n",
"'x'$\n",
`"x"` + "$\n",
"`x`$\n",
"+\n",
"-\n",
"*\n",
"/\n",
"%\n",
"&\n",
"|\n",
"^\n",
"<<\n",
">>\n",
"&^\n",
"+=\n",
"-=\n",
"*=\n",
"/=\n",
"%=\n",
"&=\n",
"|=\n",
"^=\n",
"<<=\n",
">>=\n",
"&^=\n",
"&&\n",
"||\n",
"<-\n",
"++$\n",
"--$\n",
"==\n",
"<\n",
">\n",
"=\n",
"!\n",
"!=\n",
"<=\n",
">=\n",
":=\n",
"...\n",
"(\n",
"[\n",
"{\n",
",\n",
".\n",
")$\n",
"]$\n",
"}$\n",
"#;\n",
":\n",
"break$\n",
"case\n",
"chan\n",
"const\n",
"continue$\n",
"default\n",
"defer\n",
"else\n",
"fallthrough$\n",
"for\n",
"func\n",
"go\n",
"goto\n",
"if\n",
"import\n",
"interface\n",
"map\n",
"package\n",
"range\n",
"return$\n",
"select\n",
"struct\n",
"switch\n",
"type\n",
"var\n",
"foo$//comment\n",
"foo$//comment",
"foo$/*comment*/\n",
"foo$/*\n*/",
"foo$/*comment*/ \n",
"foo$/*\n*/ ",
"foo $// comment\n",
"foo $// comment",
"foo $/*comment*/\n",
"foo $/*\n*/",
"foo $/* */ /* \n */ bar$/**/\n",
"foo $/*0*/ /*1*/ /*2*/\n",
"foo $/*comment*/ \n",
"foo $/*0*/ /*1*/ /*2*/ \n",
"foo $/**/ /*-------------*/ /*----\n*/bar $/* \n*/baa$\n",
"foo $/* an EOF terminates a line */",
"foo $/* an EOF terminates a line */ /*",
"foo $/* an EOF terminates a line */ //",
"package main$\n\nfunc main() {\n\tif {\n\t\treturn /* */ }$\n}$\n",
"package main$",
}
func TestSemis(t *testing.T) {
for _, line := range lines {
checkSemi(t, line, 0)
checkSemi(t, line, ScanComments)
// if the input ended in newlines, the input must tokenize the
// same with or without those newlines
for i := len(line) - 1; i >= 0 && line[i] == '\n'; i-- {
checkSemi(t, line[0:i], 0)
checkSemi(t, line[0:i], ScanComments)
}
}
}
type segment struct {
srcline string // a line of source text
filename string // filename for current token; error message for invalid line directives
line, column int // line and column for current token; error position for invalid line directives
}
var segments = []segment{
// exactly one token per line since the test consumes one token per segment
{" line1", "TestLineDirectives", 1, 3},
{"\nline2", "TestLineDirectives", 2, 1},
{"\nline3 //line File1.go:100", "TestLineDirectives", 3, 1}, // bad line comment, ignored
{"\nline4", "TestLineDirectives", 4, 1},
{"\n//line File1.go:100\n line100", "File1.go", 100, 0},
{"\n//line \t :42\n line1", " \t ", 42, 0},
{"\n//line File2.go:200\n line200", "File2.go", 200, 0},
{"\n//line foo\t:42\n line42", "foo\t", 42, 0},
{"\n //line foo:42\n line43", "foo\t", 44, 0}, // bad line comment, ignored (use existing, prior filename)
{"\n//line foo 42\n line44", "foo\t", 46, 0}, // bad line comment, ignored (use existing, prior filename)
{"\n//line /bar:42\n line45", "/bar", 42, 0},
{"\n//line ./foo:42\n line46", "foo", 42, 0},
{"\n//line a/b/c/File1.go:100\n line100", "a/b/c/File1.go", 100, 0},
{"\n//line c:\\bar:42\n line200", "c:\\bar", 42, 0},
{"\n//line c:\\dir\\File1.go:100\n line201", "c:\\dir\\File1.go", 100, 0},
// tests for new line directive syntax
{"\n//line :100\na1", "", 100, 0}, // missing filename means empty filename
{"\n//line bar:100\nb1", "bar", 100, 0},
{"\n//line :100:10\nc1", "bar", 100, 10}, // missing filename means current filename
{"\n//line foo:100:10\nd1", "foo", 100, 10},
{"\n/*line :100*/a2", "", 100, 0}, // missing filename means empty filename
{"\n/*line bar:100*/b2", "bar", 100, 0},
{"\n/*line :100:10*/c2", "bar", 100, 10}, // missing filename means current filename
{"\n/*line foo:100:10*/d2", "foo", 100, 10},
{"\n/*line foo:100:10*/ e2", "foo", 100, 14}, // line-directive relative column
{"\n/*line foo:100:10*/\n\nf2", "foo", 102, 1}, // absolute column since on new line
}
var dirsegments = []segment{
// exactly one token per line since the test consumes one token per segment
{" line1", "TestLineDir/TestLineDirectives", 1, 3},
{"\n//line File1.go:100\n line100", "TestLineDir/File1.go", 100, 0},
}
var dirUnixSegments = []segment{
{"\n//line /bar:42\n line42", "/bar", 42, 0},
}
var dirWindowsSegments = []segment{
{"\n//line c:\\bar:42\n line42", "c:\\bar", 42, 0},
}
// Verify that line directives are interpreted correctly.
func TestLineDirectives(t *testing.T) {
testSegments(t, segments, "TestLineDirectives")
testSegments(t, dirsegments, "TestLineDir/TestLineDirectives")
if runtime.GOOS == "windows" {
testSegments(t, dirWindowsSegments, "TestLineDir/TestLineDirectives")
} else {
testSegments(t, dirUnixSegments, "TestLineDir/TestLineDirectives")
}
}
func testSegments(t *testing.T, segments []segment, filename string) {
var src string
for _, e := range segments {
src += e.srcline
}
// verify scan
var S Scanner
file := fset.AddFile(filename, fset.Base(), len(src))
S.Init(file, []byte(src), func(pos token.Position, msg string) { t.Error(Error{pos, msg}) }, dontInsertSemis)
for _, s := range segments {
p, _, lit := S.Scan()
pos := file.Position(p)
checkPos(t, lit, p, token.Position{
Filename: s.filename,
Offset: pos.Offset,
Line: s.line,
Column: s.column,
})
}
if S.ErrorCount != 0 {
t.Errorf("got %d errors", S.ErrorCount)
}
}
// The filename is used for the error message in these test cases.
// The first line directive is valid and used to control the expected error line.
var invalidSegments = []segment{
{"\n//line :1:1\n//line foo:42 extra text\ndummy", "invalid line number: 42 extra text", 1, 12},
{"\n//line :2:1\n//line foobar:\ndummy", "invalid line number: ", 2, 15},
{"\n//line :5:1\n//line :0\ndummy", "invalid line number: 0", 5, 9},
{"\n//line :10:1\n//line :1:0\ndummy", "invalid column number: 0", 10, 11},
{"\n//line :1:1\n//line :foo:0\ndummy", "invalid line number: 0", 1, 13}, // foo is considered part of the filename
}
// Verify that invalid line directives get the correct error message.
func TestInvalidLineDirectives(t *testing.T) {
// make source
var src string
for _, e := range invalidSegments {
src += e.srcline
}
// verify scan
var S Scanner
var s segment // current segment
file := fset.AddFile(filepath.Join("dir", "TestInvalidLineDirectives"), fset.Base(), len(src))
S.Init(file, []byte(src), func(pos token.Position, msg string) {
if msg != s.filename {
t.Errorf("got error %q; want %q", msg, s.filename)
}
if pos.Line != s.line || pos.Column != s.column {
t.Errorf("got position %d:%d; want %d:%d", pos.Line, pos.Column, s.line, s.column)
}
}, dontInsertSemis)
for _, s = range invalidSegments {
S.Scan()
}
if S.ErrorCount != len(invalidSegments) {
t.Errorf("got %d errors; want %d", S.ErrorCount, len(invalidSegments))
}
}
// Verify that initializing the same scanner more than once works correctly.
func TestInit(t *testing.T) {
var s Scanner
// 1st init
src1 := "if true { }"
f1 := fset.AddFile("src1", fset.Base(), len(src1))
s.Init(f1, []byte(src1), nil, dontInsertSemis)
if f1.Size() != len(src1) {
t.Errorf("bad file size: got %d, expected %d", f1.Size(), len(src1))
}
s.Scan() // if
s.Scan() // true
_, tok, _ := s.Scan() // {
if tok != token.LBRACE {
t.Errorf("bad token: got %s, expected %s", tok, token.LBRACE)
}
// 2nd init
src2 := "go true { ]"
f2 := fset.AddFile("src2", fset.Base(), len(src2))
s.Init(f2, []byte(src2), nil, dontInsertSemis)
if f2.Size() != len(src2) {
t.Errorf("bad file size: got %d, expected %d", f2.Size(), len(src2))
}
_, tok, _ = s.Scan() // go
if tok != token.GO {
t.Errorf("bad token: got %s, expected %s", tok, token.GO)
}
if s.ErrorCount != 0 {
t.Errorf("found %d errors", s.ErrorCount)
}
}
func TestStdErrorHander(t *testing.T) {
const src = "@\n" + // illegal character, cause an error
"@ @\n" + // two errors on the same line
"//line File2:20\n" +
"@\n" + // different file, but same line
"//line File2:1\n" +
"@ @\n" + // same file, decreasing line number
"//line File1:1\n" +
"@ @ @" // original file, line 1 again
var list ErrorList
eh := func(pos token.Position, msg string) { list.Add(pos, msg) }
var s Scanner
s.Init(fset.AddFile("File1", fset.Base(), len(src)), []byte(src), eh, dontInsertSemis)
for {
if _, tok, _ := s.Scan(); tok == token.EOF {
break
}
}
if len(list) != s.ErrorCount {
t.Errorf("found %d errors, expected %d", len(list), s.ErrorCount)
}
if len(list) != 9 {
t.Errorf("found %d raw errors, expected 9", len(list))
PrintError(os.Stderr, list)
}
list.Sort()
if len(list) != 9 {
t.Errorf("found %d sorted errors, expected 9", len(list))
PrintError(os.Stderr, list)
}
list.RemoveMultiples()
if len(list) != 4 {
t.Errorf("found %d one-per-line errors, expected 4", len(list))
PrintError(os.Stderr, list)
}
}
type errorCollector struct {
cnt int // number of errors encountered
msg string // last error message encountered
pos token.Position // last error position encountered
}
func checkError(t *testing.T, src string, tok token.Token, pos int, lit, err string) {
var s Scanner
var h errorCollector
eh := func(pos token.Position, msg string) {
h.cnt++
h.msg = msg
h.pos = pos
}
s.Init(fset.AddFile("", fset.Base(), len(src)), []byte(src), eh, ScanComments|dontInsertSemis)
_, tok0, lit0 := s.Scan()
if tok0 != tok {
t.Errorf("%q: got %s, expected %s", src, tok0, tok)
}
if tok0 != token.ILLEGAL && lit0 != lit {
t.Errorf("%q: got literal %q, expected %q", src, lit0, lit)
}
cnt := 0
if err != "" {
cnt = 1
}
if h.cnt != cnt {
t.Errorf("%q: got cnt %d, expected %d", src, h.cnt, cnt)
}
if h.msg != err {
t.Errorf("%q: got msg %q, expected %q", src, h.msg, err)
}
if h.pos.Offset != pos {
t.Errorf("%q: got offset %d, expected %d", src, h.pos.Offset, pos)
}
}
var errors = []struct {
src string
tok token.Token
pos int
lit string
err string
}{
{"\a", token.ILLEGAL, 0, "", "illegal character U+0007"},
{`#`, token.ILLEGAL, 0, "", "illegal character U+0023 '#'"},
{`…`, token.ILLEGAL, 0, "", "illegal character U+2026 '…'"},
{"..", token.PERIOD, 0, "", ""}, // two periods, not invalid token (issue #28112)
{`' '`, token.CHAR, 0, `' '`, ""},
{`''`, token.CHAR, 0, `''`, "illegal rune literal"},
{`'12'`, token.CHAR, 0, `'12'`, "illegal rune literal"},
{`'123'`, token.CHAR, 0, `'123'`, "illegal rune literal"},
{`'\0'`, token.CHAR, 3, `'\0'`, "illegal character U+0027 ''' in escape sequence"},
{`'\07'`, token.CHAR, 4, `'\07'`, "illegal character U+0027 ''' in escape sequence"},
{`'\8'`, token.CHAR, 2, `'\8'`, "unknown escape sequence"},
{`'\08'`, token.CHAR, 3, `'\08'`, "illegal character U+0038 '8' in escape sequence"},
{`'\x'`, token.CHAR, 3, `'\x'`, "illegal character U+0027 ''' in escape sequence"},
{`'\x0'`, token.CHAR, 4, `'\x0'`, "illegal character U+0027 ''' in escape sequence"},
{`'\x0g'`, token.CHAR, 4, `'\x0g'`, "illegal character U+0067 'g' in escape sequence"},
{`'\u'`, token.CHAR, 3, `'\u'`, "illegal character U+0027 ''' in escape sequence"},
{`'\u0'`, token.CHAR, 4, `'\u0'`, "illegal character U+0027 ''' in escape sequence"},
{`'\u00'`, token.CHAR, 5, `'\u00'`, "illegal character U+0027 ''' in escape sequence"},
{`'\u000'`, token.CHAR, 6, `'\u000'`, "illegal character U+0027 ''' in escape sequence"},
{`'\u000`, token.CHAR, 6, `'\u000`, "escape sequence not terminated"},
{`'\u0000'`, token.CHAR, 0, `'\u0000'`, ""},
{`'\U'`, token.CHAR, 3, `'\U'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U0'`, token.CHAR, 4, `'\U0'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U00'`, token.CHAR, 5, `'\U00'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U000'`, token.CHAR, 6, `'\U000'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U0000'`, token.CHAR, 7, `'\U0000'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U00000'`, token.CHAR, 8, `'\U00000'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U000000'`, token.CHAR, 9, `'\U000000'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U0000000'`, token.CHAR, 10, `'\U0000000'`, "illegal character U+0027 ''' in escape sequence"},
{`'\U0000000`, token.CHAR, 10, `'\U0000000`, "escape sequence not terminated"},
{`'\U00000000'`, token.CHAR, 0, `'\U00000000'`, ""},
{`'\Uffffffff'`, token.CHAR, 2, `'\Uffffffff'`, "escape sequence is invalid Unicode code point"},
{`'`, token.CHAR, 0, `'`, "rune literal not terminated"},
{`'\`, token.CHAR, 2, `'\`, "escape sequence not terminated"},
{"'\n", token.CHAR, 0, "'", "rune literal not terminated"},
{"'\n ", token.CHAR, 0, "'", "rune literal not terminated"},
{`""`, token.STRING, 0, `""`, ""},
{`"abc`, token.STRING, 0, `"abc`, "string literal not terminated"},
{"\"abc\n", token.STRING, 0, `"abc`, "string literal not terminated"},
{"\"abc\n ", token.STRING, 0, `"abc`, "string literal not terminated"},
{"``", token.STRING, 0, "``", ""},
{"`", token.STRING, 0, "`", "raw string literal not terminated"},
{"/**/", token.COMMENT, 0, "/**/", ""},
{"/*", token.COMMENT, 0, "/*", "comment not terminated"},
{"077", token.INT, 0, "077", ""},
{"078.", token.FLOAT, 0, "078.", ""},
{"07801234567.", token.FLOAT, 0, "07801234567.", ""},
{"078e0", token.FLOAT, 0, "078e0", ""},
{"0E", token.FLOAT, 2, "0E", "exponent has no digits"}, // issue 17621
{"078", token.INT, 2, "078", "invalid digit '8' in octal literal"},
{"07090000008", token.INT, 3, "07090000008", "invalid digit '9' in octal literal"},
{"0x", token.INT, 2, "0x", "hexadecimal literal has no digits"},
{"\"abc\x00def\"", token.STRING, 4, "\"abc\x00def\"", "illegal character NUL"},
{"\"abc\x80def\"", token.STRING, 4, "\"abc\x80def\"", "illegal UTF-8 encoding"},
{"\ufeff\ufeff", token.ILLEGAL, 3, "\ufeff\ufeff", "illegal byte order mark"}, // only first BOM is ignored
{"//\ufeff", token.COMMENT, 2, "//\ufeff", "illegal byte order mark"}, // only first BOM is ignored
{"'\ufeff" + `'`, token.CHAR, 1, "'\ufeff" + `'`, "illegal byte order mark"}, // only first BOM is ignored
{`"` + "abc\ufeffdef" + `"`, token.STRING, 4, `"` + "abc\ufeffdef" + `"`, "illegal byte order mark"}, // only first BOM is ignored
{"abc\x00def", token.IDENT, 3, "abc", "illegal character NUL"},
{"abc\x00", token.IDENT, 3, "abc", "illegal character NUL"},
}
func TestScanErrors(t *testing.T) {
for _, e := range errors {
checkError(t, e.src, e.tok, e.pos, e.lit, e.err)
}
}
// Verify that no comments show up as literal values when skipping comments.
func TestIssue10213(t *testing.T) {
const src = `
var (
A = 1 // foo
)
var (
B = 2
// foo
)
var C = 3 // foo
var D = 4
// foo
func anycode() {
// foo
}
`
var s Scanner
s.Init(fset.AddFile("", fset.Base(), len(src)), []byte(src), nil, 0)
for {
pos, tok, lit := s.Scan()
class := tokenclass(tok)
if lit != "" && class != keyword && class != literal && tok != token.SEMICOLON {
t.Errorf("%s: tok = %s, lit = %q", fset.Position(pos), tok, lit)
}
if tok <= token.EOF {
break
}
}
}
func TestIssue28112(t *testing.T) {
const src = "... .. 0.. .." // make sure to have stand-alone ".." immediately before EOF to test EOF behavior
tokens := []token.Token{token.ELLIPSIS, token.PERIOD, token.PERIOD, token.FLOAT, token.PERIOD, token.PERIOD, token.PERIOD, token.EOF}
var s Scanner
s.Init(fset.AddFile("", fset.Base(), len(src)), []byte(src), nil, 0)
for _, want := range tokens {
pos, got, lit := s.Scan()
if got != want {
t.Errorf("%s: got %s, want %s", fset.Position(pos), got, want)
}
// literals expect to have a (non-empty) literal string and we don't care about other tokens for this test
if tokenclass(got) == literal && lit == "" {
t.Errorf("%s: for %s got empty literal string", fset.Position(pos), got)
}
}
}
func BenchmarkScan(b *testing.B) {
b.StopTimer()
fset := token.NewFileSet()
file := fset.AddFile("", fset.Base(), len(source))
var s Scanner
b.StartTimer()
for i := 0; i < b.N; i++ {
s.Init(file, source, nil, ScanComments)
for {
_, tok, _ := s.Scan()
if tok == token.EOF {
break
}
}
}
}
func BenchmarkScanFiles(b *testing.B) {
// Scan a few arbitrary large files, and one small one, to provide some
// variety in benchmarks.
for _, p := range []string{
"go/types/expr.go",
"go/parser/parser.go",
"net/http/server.go",
"go/scanner/errors.go",
} {
b.Run(p, func(b *testing.B) {
b.StopTimer()
filename := filepath.Join("..", "..", filepath.FromSlash(p))
src, err := os.ReadFile(filename)
if err != nil {
b.Fatal(err)
}
fset := token.NewFileSet()
file := fset.AddFile(filename, fset.Base(), len(src))
b.SetBytes(int64(len(src)))
var s Scanner
b.StartTimer()
for i := 0; i < b.N; i++ {
s.Init(file, src, nil, ScanComments)
for {
_, tok, _ := s.Scan()
if tok == token.EOF {
break
}
}
}
})
}
}
func TestNumbers(t *testing.T) {
for _, test := range []struct {
tok token.Token
src, tokens, err string
}{
// binaries
{token.INT, "0b0", "0b0", ""},
{token.INT, "0b1010", "0b1010", ""},
{token.INT, "0B1110", "0B1110", ""},
{token.INT, "0b", "0b", "binary literal has no digits"},
{token.INT, "0b0190", "0b0190", "invalid digit '9' in binary literal"},
{token.INT, "0b01a0", "0b01 a0", ""}, // only accept 0-9
{token.FLOAT, "0b.", "0b.", "invalid radix point in binary literal"},
{token.FLOAT, "0b.1", "0b.1", "invalid radix point in binary literal"},
{token.FLOAT, "0b1.0", "0b1.0", "invalid radix point in binary literal"},
{token.FLOAT, "0b1e10", "0b1e10", "'e' exponent requires decimal mantissa"},
{token.FLOAT, "0b1P-1", "0b1P-1", "'P' exponent requires hexadecimal mantissa"},
{token.IMAG, "0b10i", "0b10i", ""},
{token.IMAG, "0b10.0i", "0b10.0i", "invalid radix point in binary literal"},
// octals
{token.INT, "0o0", "0o0", ""},
{token.INT, "0o1234", "0o1234", ""},
{token.INT, "0O1234", "0O1234", ""},
{token.INT, "0o", "0o", "octal literal has no digits"},
{token.INT, "0o8123", "0o8123", "invalid digit '8' in octal literal"},
{token.INT, "0o1293", "0o1293", "invalid digit '9' in octal literal"},
{token.INT, "0o12a3", "0o12 a3", ""}, // only accept 0-9
{token.FLOAT, "0o.", "0o.", "invalid radix point in octal literal"},
{token.FLOAT, "0o.2", "0o.2", "invalid radix point in octal literal"},
{token.FLOAT, "0o1.2", "0o1.2", "invalid radix point in octal literal"},
{token.FLOAT, "0o1E+2", "0o1E+2", "'E' exponent requires decimal mantissa"},
{token.FLOAT, "0o1p10", "0o1p10", "'p' exponent requires hexadecimal mantissa"},
{token.IMAG, "0o10i", "0o10i", ""},
{token.IMAG, "0o10e0i", "0o10e0i", "'e' exponent requires decimal mantissa"},
// 0-octals
{token.INT, "0", "0", ""},
{token.INT, "0123", "0123", ""},
{token.INT, "08123", "08123", "invalid digit '8' in octal literal"},
{token.INT, "01293", "01293", "invalid digit '9' in octal literal"},
{token.INT, "0F.", "0 F .", ""}, // only accept 0-9
{token.INT, "0123F.", "0123 F .", ""},
{token.INT, "0123456x", "0123456 x", ""},
// decimals
{token.INT, "1", "1", ""},
{token.INT, "1234", "1234", ""},
{token.INT, "1f", "1 f", ""}, // only accept 0-9
{token.IMAG, "0i", "0i", ""},
{token.IMAG, "0678i", "0678i", ""},
// decimal floats
{token.FLOAT, "0.", "0.", ""},
{token.FLOAT, "123.", "123.", ""},
{token.FLOAT, "0123.", "0123.", ""},
{token.FLOAT, ".0", ".0", ""},
{token.FLOAT, ".123", ".123", ""},
{token.FLOAT, ".0123", ".0123", ""},
{token.FLOAT, "0.0", "0.0", ""},
{token.FLOAT, "123.123", "123.123", ""},
{token.FLOAT, "0123.0123", "0123.0123", ""},
{token.FLOAT, "0e0", "0e0", ""},
{token.FLOAT, "123e+0", "123e+0", ""},
{token.FLOAT, "0123E-1", "0123E-1", ""},
{token.FLOAT, "0.e+1", "0.e+1", ""},
{token.FLOAT, "123.E-10", "123.E-10", ""},
{token.FLOAT, "0123.e123", "0123.e123", ""},
{token.FLOAT, ".0e-1", ".0e-1", ""},
{token.FLOAT, ".123E+10", ".123E+10", ""},
{token.FLOAT, ".0123E123", ".0123E123", ""},
{token.FLOAT, "0.0e1", "0.0e1", ""},
{token.FLOAT, "123.123E-10", "123.123E-10", ""},
{token.FLOAT, "0123.0123e+456", "0123.0123e+456", ""},
{token.FLOAT, "0e", "0e", "exponent has no digits"},
{token.FLOAT, "0E+", "0E+", "exponent has no digits"},
{token.FLOAT, "1e+f", "1e+ f", "exponent has no digits"},
{token.FLOAT, "0p0", "0p0", "'p' exponent requires hexadecimal mantissa"},
{token.FLOAT, "1.0P-1", "1.0P-1", "'P' exponent requires hexadecimal mantissa"},
{token.IMAG, "0.i", "0.i", ""},
{token.IMAG, ".123i", ".123i", ""},
{token.IMAG, "123.123i", "123.123i", ""},
{token.IMAG, "123e+0i", "123e+0i", ""},
{token.IMAG, "123.E-10i", "123.E-10i", ""},
{token.IMAG, ".123E+10i", ".123E+10i", ""},
// hexadecimals
{token.INT, "0x0", "0x0", ""},
{token.INT, "0x1234", "0x1234", ""},
{token.INT, "0xcafef00d", "0xcafef00d", ""},
{token.INT, "0XCAFEF00D", "0XCAFEF00D", ""},
{token.INT, "0x", "0x", "hexadecimal literal has no digits"},
{token.INT, "0x1g", "0x1 g", ""},
{token.IMAG, "0xf00i", "0xf00i", ""},
// hexadecimal floats
{token.FLOAT, "0x0p0", "0x0p0", ""},
{token.FLOAT, "0x12efp-123", "0x12efp-123", ""},
{token.FLOAT, "0xABCD.p+0", "0xABCD.p+0", ""},
{token.FLOAT, "0x.0189P-0", "0x.0189P-0", ""},
{token.FLOAT, "0x1.ffffp+1023", "0x1.ffffp+1023", ""},
{token.FLOAT, "0x.", "0x.", "hexadecimal literal has no digits"},
{token.FLOAT, "0x0.", "0x0.", "hexadecimal mantissa requires a 'p' exponent"},
{token.FLOAT, "0x.0", "0x.0", "hexadecimal mantissa requires a 'p' exponent"},
{token.FLOAT, "0x1.1", "0x1.1", "hexadecimal mantissa requires a 'p' exponent"},
{token.FLOAT, "0x1.1e0", "0x1.1e0", "hexadecimal mantissa requires a 'p' exponent"},
{token.FLOAT, "0x1.2gp1a", "0x1.2 gp1a", "hexadecimal mantissa requires a 'p' exponent"},
{token.FLOAT, "0x0p", "0x0p", "exponent has no digits"},
{token.FLOAT, "0xeP-", "0xeP-", "exponent has no digits"},
{token.FLOAT, "0x1234PAB", "0x1234P AB", "exponent has no digits"},
{token.FLOAT, "0x1.2p1a", "0x1.2p1 a", ""},
{token.IMAG, "0xf00.bap+12i", "0xf00.bap+12i", ""},
// separators
{token.INT, "0b_1000_0001", "0b_1000_0001", ""},
{token.INT, "0o_600", "0o_600", ""},
{token.INT, "0_466", "0_466", ""},
{token.INT, "1_000", "1_000", ""},
{token.FLOAT, "1_000.000_1", "1_000.000_1", ""},
{token.IMAG, "10e+1_2_3i", "10e+1_2_3i", ""},
{token.INT, "0x_f00d", "0x_f00d", ""},
{token.FLOAT, "0x_f00d.0p1_2", "0x_f00d.0p1_2", ""},
{token.INT, "0b__1000", "0b__1000", "'_' must separate successive digits"},
{token.INT, "0o60___0", "0o60___0", "'_' must separate successive digits"},
{token.INT, "0466_", "0466_", "'_' must separate successive digits"},
{token.FLOAT, "1_.", "1_.", "'_' must separate successive digits"},
{token.FLOAT, "0._1", "0._1", "'_' must separate successive digits"},
{token.FLOAT, "2.7_e0", "2.7_e0", "'_' must separate successive digits"},
{token.IMAG, "10e+12_i", "10e+12_i", "'_' must separate successive digits"},
{token.INT, "0x___0", "0x___0", "'_' must separate successive digits"},
{token.FLOAT, "0x1.0_p0", "0x1.0_p0", "'_' must separate successive digits"},
} {
var s Scanner
var err string
s.Init(fset.AddFile("", fset.Base(), len(test.src)), []byte(test.src), func(_ token.Position, msg string) {
if err == "" {
err = msg
}
}, 0)
for i, want := range strings.Split(test.tokens, " ") {
err = ""
_, tok, lit := s.Scan()
// compute lit where for tokens where lit is not defined
switch tok {
case token.PERIOD:
lit = "."
case token.ADD:
lit = "+"
case token.SUB:
lit = "-"
}
if i == 0 {
if tok != test.tok {
t.Errorf("%q: got token %s; want %s", test.src, tok, 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, tok, want)
}
}
// make sure we read all
_, tok, _ := s.Scan()
if tok == token.SEMICOLON {
_, tok, _ = s.Scan()
}
if tok != token.EOF {
t.Errorf("%q: got %s; want EOF", test.src, tok)
}
}
}
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