blob: 8d2e6f5c64e86448d8fe6e16d6112b794492771e [file] [log] [blame]
// 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 fmt_test
import (
"bufio"
"bytes"
. "fmt"
"io"
"math"
"os"
"reflect"
"regexp"
"strings"
"testing"
"utf8"
)
type ScanTest struct {
text string
in interface{}
out interface{}
}
type ScanfTest struct {
format string
text string
in interface{}
out interface{}
}
type ScanfMultiTest struct {
format string
text string
in []interface{}
out []interface{}
err string
}
var (
boolVal bool
intVal int
int8Val int8
int16Val int16
int32Val int32
int64Val int64
uintVal uint
uint8Val uint8
uint16Val uint16
uint32Val uint32
uint64Val uint64
float32Val float32
float64Val float64
stringVal string
stringVal1 string
bytesVal []byte
complex64Val complex64
complex128Val complex128
renamedBoolVal renamedBool
renamedIntVal renamedInt
renamedInt8Val renamedInt8
renamedInt16Val renamedInt16
renamedInt32Val renamedInt32
renamedInt64Val renamedInt64
renamedUintVal renamedUint
renamedUint8Val renamedUint8
renamedUint16Val renamedUint16
renamedUint32Val renamedUint32
renamedUint64Val renamedUint64
renamedUintptrVal renamedUintptr
renamedStringVal renamedString
renamedBytesVal renamedBytes
renamedFloat32Val renamedFloat32
renamedFloat64Val renamedFloat64
renamedComplex64Val renamedComplex64
renamedComplex128Val renamedComplex128
)
type FloatTest struct {
text string
in float64
out float64
}
// Xs accepts any non-empty run of the verb character
type Xs string
func (x *Xs) Scan(state ScanState, verb int) os.Error {
tok, err := state.Token(true, func(r int) bool { return r == verb })
if err != nil {
return err
}
s := string(tok)
if !regexp.MustCompile("^" + string(verb) + "+$").MatchString(s) {
return os.ErrorString("syntax error for xs")
}
*x = Xs(s)
return nil
}
var xVal Xs
// IntString accepts an integer followed immediately by a string.
// It tests the embedding of a scan within a scan.
type IntString struct {
i int
s string
}
func (s *IntString) Scan(state ScanState, verb int) os.Error {
if _, err := Fscan(state, &s.i); err != nil {
return err
}
tok, err := state.Token(true, nil)
if err != nil {
return err
}
s.s = string(tok)
return nil
}
var intStringVal IntString
// myStringReader implements Read but not ReadRune, allowing us to test our readRune wrapper
// type that creates something that can read runes given only Read().
type myStringReader struct {
r *strings.Reader
}
func (s *myStringReader) Read(p []byte) (n int, err os.Error) {
return s.r.Read(p)
}
func newReader(s string) *myStringReader {
return &myStringReader{strings.NewReader(s)}
}
var scanTests = []ScanTest{
// Basic types
{"T\n", &boolVal, true}, // boolean test vals toggle to be sure they are written
{"F\n", &boolVal, false}, // restored to zero value
{"21\n", &intVal, 21},
{"0\n", &intVal, 0},
{"000\n", &intVal, 0},
{"0x10\n", &intVal, 0x10},
{"-0x10\n", &intVal, -0x10},
{"0377\n", &intVal, 0377},
{"-0377\n", &intVal, -0377},
{"0\n", &uintVal, uint(0)},
{"000\n", &uintVal, uint(0)},
{"0x10\n", &uintVal, uint(0x10)},
{"0377\n", &uintVal, uint(0377)},
{"22\n", &int8Val, int8(22)},
{"23\n", &int16Val, int16(23)},
{"24\n", &int32Val, int32(24)},
{"25\n", &int64Val, int64(25)},
{"127\n", &int8Val, int8(127)},
{"-21\n", &intVal, -21},
{"-22\n", &int8Val, int8(-22)},
{"-23\n", &int16Val, int16(-23)},
{"-24\n", &int32Val, int32(-24)},
{"-25\n", &int64Val, int64(-25)},
{"-128\n", &int8Val, int8(-128)},
{"+21\n", &intVal, +21},
{"+22\n", &int8Val, int8(+22)},
{"+23\n", &int16Val, int16(+23)},
{"+24\n", &int32Val, int32(+24)},
{"+25\n", &int64Val, int64(+25)},
{"+127\n", &int8Val, int8(+127)},
{"26\n", &uintVal, uint(26)},
{"27\n", &uint8Val, uint8(27)},
{"28\n", &uint16Val, uint16(28)},
{"29\n", &uint32Val, uint32(29)},
{"30\n", &uint64Val, uint64(30)},
{"255\n", &uint8Val, uint8(255)},
{"32767\n", &int16Val, int16(32767)},
{"2.3\n", &float64Val, 2.3},
{"2.3e1\n", &float32Val, float32(2.3e1)},
{"2.3e2\n", &float64Val, 2.3e2},
{"2.3p2\n", &float64Val, 2.3 * 4},
{"2.3p+2\n", &float64Val, 2.3 * 4},
{"2.3p+66\n", &float64Val, 2.3 * (1 << 32) * (1 << 32) * 4},
{"2.3p-66\n", &float64Val, 2.3 / ((1 << 32) * (1 << 32) * 4)},
{"2.35\n", &stringVal, "2.35"},
{"2345678\n", &bytesVal, []byte("2345678")},
{"(3.4e1-2i)\n", &complex128Val, 3.4e1 - 2i},
{"-3.45e1-3i\n", &complex64Val, complex64(-3.45e1 - 3i)},
{"-.45e1-1e2i\n", &complex128Val, complex128(-.45e1 - 100i)},
{"hello\n", &stringVal, "hello"},
// Renamed types
{"true\n", &renamedBoolVal, renamedBool(true)},
{"F\n", &renamedBoolVal, renamedBool(false)},
{"101\n", &renamedIntVal, renamedInt(101)},
{"102\n", &renamedIntVal, renamedInt(102)},
{"103\n", &renamedUintVal, renamedUint(103)},
{"104\n", &renamedUintVal, renamedUint(104)},
{"105\n", &renamedInt8Val, renamedInt8(105)},
{"106\n", &renamedInt16Val, renamedInt16(106)},
{"107\n", &renamedInt32Val, renamedInt32(107)},
{"108\n", &renamedInt64Val, renamedInt64(108)},
{"109\n", &renamedUint8Val, renamedUint8(109)},
{"110\n", &renamedUint16Val, renamedUint16(110)},
{"111\n", &renamedUint32Val, renamedUint32(111)},
{"112\n", &renamedUint64Val, renamedUint64(112)},
{"113\n", &renamedUintptrVal, renamedUintptr(113)},
{"114\n", &renamedStringVal, renamedString("114")},
{"115\n", &renamedBytesVal, renamedBytes([]byte("115"))},
// Custom scanners.
{" vvv ", &xVal, Xs("vvv")},
{" 1234hello", &intStringVal, IntString{1234, "hello"}},
// Fixed bugs
{"2147483648\n", &int64Val, int64(2147483648)}, // was: integer overflow
}
var scanfTests = []ScanfTest{
{"%v", "TRUE\n", &boolVal, true},
{"%t", "false\n", &boolVal, false},
{"%v", "-71\n", &intVal, -71},
{"%v", "0377\n", &intVal, 0377},
{"%v", "0x44\n", &intVal, 0x44},
{"%d", "72\n", &intVal, 72},
{"%c", "a\n", &intVal, 'a'},
{"%c", "\u5072\n", &intVal, 0x5072},
{"%c", "\u1234\n", &intVal, '\u1234'},
{"%d", "73\n", &int8Val, int8(73)},
{"%d", "+74\n", &int16Val, int16(74)},
{"%d", "75\n", &int32Val, int32(75)},
{"%d", "76\n", &int64Val, int64(76)},
{"%b", "1001001\n", &intVal, 73},
{"%o", "075\n", &intVal, 075},
{"%x", "a75\n", &intVal, 0xa75},
{"%v", "71\n", &uintVal, uint(71)},
{"%d", "72\n", &uintVal, uint(72)},
{"%d", "73\n", &uint8Val, uint8(73)},
{"%d", "74\n", &uint16Val, uint16(74)},
{"%d", "75\n", &uint32Val, uint32(75)},
{"%d", "76\n", &uint64Val, uint64(76)},
{"%b", "1001001\n", &uintVal, uint(73)},
{"%o", "075\n", &uintVal, uint(075)},
{"%x", "a75\n", &uintVal, uint(0xa75)},
{"%x", "A75\n", &uintVal, uint(0xa75)},
{"%U", "U+1234\n", &intVal, int(0x1234)},
{"%U", "U+4567\n", &uintVal, uint(0x4567)},
// Strings
{"%s", "using-%s\n", &stringVal, "using-%s"},
{"%x", "7573696e672d2578\n", &stringVal, "using-%x"},
{"%q", `"quoted\twith\\do\u0075bl\x65s"` + "\n", &stringVal, "quoted\twith\\doubles"},
{"%q", "`quoted with backs`\n", &stringVal, "quoted with backs"},
// Byte slices
{"%s", "bytes-%s\n", &bytesVal, []byte("bytes-%s")},
{"%x", "62797465732d2578\n", &bytesVal, []byte("bytes-%x")},
{"%q", `"bytes\rwith\vdo\u0075bl\x65s"` + "\n", &bytesVal, []byte("bytes\rwith\vdoubles")},
{"%q", "`bytes with backs`\n", &bytesVal, []byte("bytes with backs")},
// Renamed types
{"%v\n", "true\n", &renamedBoolVal, renamedBool(true)},
{"%t\n", "F\n", &renamedBoolVal, renamedBool(false)},
{"%v", "101\n", &renamedIntVal, renamedInt(101)},
{"%c", "\u0101\n", &renamedIntVal, renamedInt('\u0101')},
{"%o", "0146\n", &renamedIntVal, renamedInt(102)},
{"%v", "103\n", &renamedUintVal, renamedUint(103)},
{"%d", "104\n", &renamedUintVal, renamedUint(104)},
{"%d", "105\n", &renamedInt8Val, renamedInt8(105)},
{"%d", "106\n", &renamedInt16Val, renamedInt16(106)},
{"%d", "107\n", &renamedInt32Val, renamedInt32(107)},
{"%d", "108\n", &renamedInt64Val, renamedInt64(108)},
{"%x", "6D\n", &renamedUint8Val, renamedUint8(109)},
{"%o", "0156\n", &renamedUint16Val, renamedUint16(110)},
{"%d", "111\n", &renamedUint32Val, renamedUint32(111)},
{"%d", "112\n", &renamedUint64Val, renamedUint64(112)},
{"%d", "113\n", &renamedUintptrVal, renamedUintptr(113)},
{"%s", "114\n", &renamedStringVal, renamedString("114")},
{"%q", "\"1155\"\n", &renamedBytesVal, renamedBytes([]byte("1155"))},
{"%g", "116e1\n", &renamedFloat32Val, renamedFloat32(116e1)},
{"%g", "-11.7e+1", &renamedFloat64Val, renamedFloat64(-11.7e+1)},
{"%g", "11+6e1i\n", &renamedComplex64Val, renamedComplex64(11 + 6e1i)},
{"%g", "-11.+7e+1i", &renamedComplex128Val, renamedComplex128(-11. + 7e+1i)},
// Interesting formats
{"here is\tthe value:%d", "here is the\tvalue:118\n", &intVal, 118},
{"%% %%:%d", "% %:119\n", &intVal, 119},
// Corner cases
{"%x", "FFFFFFFF\n", &uint32Val, uint32(0xFFFFFFFF)},
// Custom scanner.
{"%s", " sss ", &xVal, Xs("sss")},
{"%2s", "sssss", &xVal, Xs("ss")},
// Fixed bugs
{"%d\n", "27\n", &intVal, 27}, // ok
{"%d\n", "28 \n", &intVal, 28}, // was: "unexpected newline"
}
var overflowTests = []ScanTest{
{"128", &int8Val, 0},
{"32768", &int16Val, 0},
{"-129", &int8Val, 0},
{"-32769", &int16Val, 0},
{"256", &uint8Val, 0},
{"65536", &uint16Val, 0},
{"1e100", &float32Val, 0},
{"1e500", &float64Val, 0},
{"(1e100+0i)", &complex64Val, 0},
{"(1+1e100i)", &complex64Val, 0},
{"(1-1e500i)", &complex128Val, 0},
}
var i, j, k int
var f float64
var s, t string
var c complex128
var x, y Xs
var z IntString
var multiTests = []ScanfMultiTest{
{"", "", nil, nil, ""},
{"%d", "23", args(&i), args(23), ""},
{"%2s%3s", "22333", args(&s, &t), args("22", "333"), ""},
{"%2d%3d", "44555", args(&i, &j), args(44, 555), ""},
{"%2d.%3d", "66.777", args(&i, &j), args(66, 777), ""},
{"%d, %d", "23, 18", args(&i, &j), args(23, 18), ""},
{"%3d22%3d", "33322333", args(&i, &j), args(333, 333), ""},
{"%6vX=%3fY", "3+2iX=2.5Y", args(&c, &f), args((3 + 2i), 2.5), ""},
{"%d%s", "123abc", args(&i, &s), args(123, "abc"), ""},
{"%c%c%c", "2\u50c2X", args(&i, &j, &k), args('2', '\u50c2', 'X'), ""},
// Custom scanners.
{"%e%f", "eefffff", args(&x, &y), args(Xs("ee"), Xs("fffff")), ""},
{"%4v%s", "12abcd", args(&z, &s), args(IntString{12, "ab"}, "cd"), ""},
// Errors
{"%t", "23 18", args(&i), nil, "bad verb"},
{"%d %d %d", "23 18", args(&i, &j), args(23, 18), "too few operands"},
{"%d %d", "23 18 27", args(&i, &j, &k), args(23, 18), "too many operands"},
{"%c", "\u0100", args(&int8Val), nil, "overflow"},
{"X%d", "10X", args(&intVal), nil, "input does not match format"},
// Bad UTF-8: should see every byte.
{"%c%c%c", "\xc2X\xc2", args(&i, &j, &k), args(utf8.RuneError, 'X', utf8.RuneError), ""},
}
func testScan(name string, t *testing.T, scan func(r io.Reader, a ...interface{}) (int, os.Error)) {
for _, test := range scanTests {
var r io.Reader
if name == "StringReader" {
r = strings.NewReader(test.text)
} else {
r = newReader(test.text)
}
n, err := scan(r, test.in)
if err != nil {
m := ""
if n > 0 {
m = Sprintf(" (%d fields ok)", n)
}
t.Errorf("%s got error scanning %q: %s%s", name, test.text, err, m)
continue
}
if n != 1 {
t.Errorf("%s count error on entry %q: got %d", name, test.text, n)
continue
}
// The incoming value may be a pointer
v := reflect.NewValue(test.in)
if p, ok := v.(*reflect.PtrValue); ok {
v = p.Elem()
}
val := v.Interface()
if !reflect.DeepEqual(val, test.out) {
t.Errorf("%s scanning %q: expected %v got %v, type %T", name, test.text, test.out, val, val)
}
}
}
func TestScan(t *testing.T) {
testScan("StringReader", t, Fscan)
}
func TestMyReaderScan(t *testing.T) {
testScan("myStringReader", t, Fscan)
}
func TestScanln(t *testing.T) {
testScan("StringReader", t, Fscanln)
}
func TestMyReaderScanln(t *testing.T) {
testScan("myStringReader", t, Fscanln)
}
func TestScanf(t *testing.T) {
for _, test := range scanfTests {
n, err := Sscanf(test.text, test.format, test.in)
if err != nil {
t.Errorf("got error scanning (%q, %q): %s", test.format, test.text, err)
continue
}
if n != 1 {
t.Errorf("count error on entry (%q, %q): got %d", test.format, test.text, n)
continue
}
// The incoming value may be a pointer
v := reflect.NewValue(test.in)
if p, ok := v.(*reflect.PtrValue); ok {
v = p.Elem()
}
val := v.Interface()
if !reflect.DeepEqual(val, test.out) {
t.Errorf("scanning (%q, %q): expected %v got %v, type %T", test.format, test.text, test.out, val, val)
}
}
}
func TestScanOverflow(t *testing.T) {
// different machines and different types report errors with different strings.
re := regexp.MustCompile("overflow|too large|out of range|not representable")
for _, test := range overflowTests {
_, err := Sscan(test.text, test.in)
if err == nil {
t.Errorf("expected overflow scanning %q", test.text)
continue
}
if !re.MatchString(err.String()) {
t.Errorf("expected overflow error scanning %q: %s", test.text, err)
}
}
}
func verifyNaN(str string, t *testing.T) {
var f float64
var f32 float32
var f64 float64
text := str + " " + str + " " + str
n, err := Fscan(strings.NewReader(text), &f, &f32, &f64)
if err != nil {
t.Errorf("got error scanning %q: %s", text, err)
}
if n != 3 {
t.Errorf("count error scanning %q: got %d", text, n)
}
if !math.IsNaN(float64(f)) || !math.IsNaN(float64(f32)) || !math.IsNaN(f64) {
t.Errorf("didn't get NaNs scanning %q: got %g %g %g", text, f, f32, f64)
}
}
func TestNaN(t *testing.T) {
for _, s := range []string{"nan", "NAN", "NaN"} {
verifyNaN(s, t)
}
}
func verifyInf(str string, t *testing.T) {
var f float64
var f32 float32
var f64 float64
text := str + " " + str + " " + str
n, err := Fscan(strings.NewReader(text), &f, &f32, &f64)
if err != nil {
t.Errorf("got error scanning %q: %s", text, err)
}
if n != 3 {
t.Errorf("count error scanning %q: got %d", text, n)
}
sign := 1
if str[0] == '-' {
sign = -1
}
if !math.IsInf(float64(f), sign) || !math.IsInf(float64(f32), sign) || !math.IsInf(f64, sign) {
t.Errorf("didn't get right Infs scanning %q: got %g %g %g", text, f, f32, f64)
}
}
func TestInf(t *testing.T) {
for _, s := range []string{"inf", "+inf", "-inf", "INF", "-INF", "+INF", "Inf", "-Inf", "+Inf"} {
verifyInf(s, t)
}
}
func testScanfMulti(name string, t *testing.T) {
sliceType := reflect.Typeof(make([]interface{}, 1)).(*reflect.SliceType)
for _, test := range multiTests {
var r io.Reader
if name == "StringReader" {
r = strings.NewReader(test.text)
} else {
r = newReader(test.text)
}
n, err := Fscanf(r, test.format, test.in...)
if err != nil {
if test.err == "" {
t.Errorf("got error scanning (%q, %q): %q", test.format, test.text, err)
} else if strings.Index(err.String(), test.err) < 0 {
t.Errorf("got wrong error scanning (%q, %q): %q; expected %q", test.format, test.text, err, test.err)
}
continue
}
if test.err != "" {
t.Errorf("expected error %q error scanning (%q, %q)", test.err, test.format, test.text)
}
if n != len(test.out) {
t.Errorf("count error on entry (%q, %q): expected %d got %d", test.format, test.text, len(test.out), n)
continue
}
// Convert the slice of pointers into a slice of values
resultVal := reflect.MakeSlice(sliceType, n, n)
for i := 0; i < n; i++ {
v := reflect.NewValue(test.in[i]).(*reflect.PtrValue).Elem()
resultVal.Elem(i).(*reflect.InterfaceValue).Set(v)
}
result := resultVal.Interface()
if !reflect.DeepEqual(result, test.out) {
t.Errorf("scanning (%q, %q): expected %v got %v", test.format, test.text, test.out, result)
}
}
}
func TestScanfMulti(t *testing.T) {
testScanfMulti("StringReader", t)
}
func TestMyReaderScanfMulti(t *testing.T) {
testScanfMulti("myStringReader", t)
}
func TestScanMultiple(t *testing.T) {
var a int
var s string
n, err := Sscan("123abc", &a, &s)
if n != 2 {
t.Errorf("Sscan count error: expected 2: got %d", n)
}
if err != nil {
t.Errorf("Sscan expected no error; got %s", err)
}
if a != 123 || s != "abc" {
t.Errorf("Sscan wrong values: got (%d %q) expected (123 \"abc\")", a, s)
}
n, err = Sscan("asdf", &s, &a)
if n != 1 {
t.Errorf("Sscan count error: expected 1: got %d", n)
}
if err == nil {
t.Errorf("Sscan expected error; got none: %s", err)
}
if s != "asdf" {
t.Errorf("Sscan wrong values: got %q expected \"asdf\"", s)
}
}
// Empty strings are not valid input when scanning a string.
func TestScanEmpty(t *testing.T) {
var s1, s2 string
n, err := Sscan("abc", &s1, &s2)
if n != 1 {
t.Errorf("Sscan count error: expected 1: got %d", n)
}
if err == nil {
t.Error("Sscan <one item> expected error; got none")
}
if s1 != "abc" {
t.Errorf("Sscan wrong values: got %q expected \"abc\"", s1)
}
n, err = Sscan("", &s1, &s2)
if n != 0 {
t.Errorf("Sscan count error: expected 0: got %d", n)
}
if err == nil {
t.Error("Sscan <empty> expected error; got none")
}
// Quoted empty string is OK.
n, err = Sscanf(`""`, "%q", &s1)
if n != 1 {
t.Errorf("Sscanf count error: expected 1: got %d", n)
}
if err != nil {
t.Errorf("Sscanf <empty> expected no error with quoted string; got %s", err)
}
}
func TestScanNotPointer(t *testing.T) {
r := strings.NewReader("1")
var a int
_, err := Fscan(r, a)
if err == nil {
t.Error("expected error scanning non-pointer")
} else if strings.Index(err.String(), "pointer") < 0 {
t.Errorf("expected pointer error scanning non-pointer, got: %s", err)
}
}
func TestScanlnNoNewline(t *testing.T) {
var a int
_, err := Sscanln("1 x\n", &a)
if err == nil {
t.Error("expected error scanning string missing newline")
} else if strings.Index(err.String(), "newline") < 0 {
t.Errorf("expected newline error scanning string missing newline, got: %s", err)
}
}
func TestScanlnWithMiddleNewline(t *testing.T) {
r := strings.NewReader("123\n456\n")
var a, b int
_, err := Fscanln(r, &a, &b)
if err == nil {
t.Error("expected error scanning string with extra newline")
} else if strings.Index(err.String(), "newline") < 0 {
t.Errorf("expected newline error scanning string with extra newline, got: %s", err)
}
}
// Special Reader that counts reads at end of file.
type eofCounter struct {
reader *strings.Reader
eofCount int
}
func (ec *eofCounter) Read(b []byte) (n int, err os.Error) {
n, err = ec.reader.Read(b)
if n == 0 {
ec.eofCount++
}
return
}
// Verify that when we scan, we see at most EOF once per call to a Scan function,
// and then only when it's really an EOF
func TestEOF(t *testing.T) {
ec := &eofCounter{strings.NewReader("123\n"), 0}
var a int
n, err := Fscanln(ec, &a)
if err != nil {
t.Error("unexpected error", err)
}
if n != 1 {
t.Error("expected to scan one item, got", n)
}
if ec.eofCount != 0 {
t.Error("expected zero EOFs", ec.eofCount)
ec.eofCount = 0 // reset for next test
}
n, err = Fscanln(ec, &a)
if err == nil {
t.Error("expected error scanning empty string")
}
if n != 0 {
t.Error("expected to scan zero items, got", n)
}
if ec.eofCount != 1 {
t.Error("expected one EOF, got", ec.eofCount)
}
}
// Verify that, at least when using bufio, successive calls to Fscan do not lose runes.
func TestUnreadRuneWithBufio(t *testing.T) {
r := bufio.NewReader(strings.NewReader("123αb"))
var i int
var a string
n, err := Fscanf(r, "%d", &i)
if n != 1 || err != nil {
t.Errorf("reading int expected one item, no errors; got %d %q", n, err)
}
if i != 123 {
t.Errorf("expected 123; got %d", i)
}
n, err = Fscanf(r, "%s", &a)
if n != 1 || err != nil {
t.Errorf("reading string expected one item, no errors; got %d %q", n, err)
}
if a != "αb" {
t.Errorf("expected αb; got %q", a)
}
}
type TwoLines string
// Attempt to read two lines into the object. Scanln should prevent this
// because it stops at newline; Scan and Scanf should be fine.
func (t *TwoLines) Scan(state ScanState, verb int) os.Error {
chars := make([]int, 0, 100)
for nlCount := 0; nlCount < 2; {
c, _, err := state.ReadRune()
if err != nil {
return err
}
chars = append(chars, c)
if c == '\n' {
nlCount++
}
}
*t = TwoLines(string(chars))
return nil
}
func TestMultiLine(t *testing.T) {
input := "abc\ndef\n"
// Sscan should work
var tscan TwoLines
n, err := Sscan(input, &tscan)
if n != 1 {
t.Errorf("Sscan: expected 1 item; got %d", n)
}
if err != nil {
t.Errorf("Sscan: expected no error; got %s", err)
}
if string(tscan) != input {
t.Errorf("Sscan: expected %q; got %q", input, tscan)
}
// Sscanf should work
var tscanf TwoLines
n, err = Sscanf(input, "%s", &tscanf)
if n != 1 {
t.Errorf("Sscanf: expected 1 item; got %d", n)
}
if err != nil {
t.Errorf("Sscanf: expected no error; got %s", err)
}
if string(tscanf) != input {
t.Errorf("Sscanf: expected %q; got %q", input, tscanf)
}
// Sscanln should not work
var tscanln TwoLines
n, err = Sscanln(input, &tscanln)
if n != 0 {
t.Errorf("Sscanln: expected 0 items; got %d: %q", n, tscanln)
}
if err == nil {
t.Error("Sscanln: expected error; got none")
} else if err != io.ErrUnexpectedEOF {
t.Errorf("Sscanln: expected io.ErrUnexpectedEOF (ha!); got %s", err)
}
}
// RecursiveInt accepts an string matching %d.%d.%d....
// and parses it into a linked list.
// It allows us to benchmark recursive descent style scanners.
type RecursiveInt struct {
i int
next *RecursiveInt
}
func (r *RecursiveInt) Scan(state ScanState, verb int) (err os.Error) {
_, err = Fscan(state, &r.i)
if err != nil {
return
}
next := new(RecursiveInt)
_, err = Fscanf(state, ".%v", next)
if err != nil {
if err == os.ErrorString("input does not match format") || err == io.ErrUnexpectedEOF {
err = nil
}
return
}
r.next = next
return
}
// Perform the same scanning task as RecursiveInt.Scan
// but without recurring through scanner, so we can compare
// performance more directly.
func scanInts(r *RecursiveInt, b *bytes.Buffer) (err os.Error) {
r.next = nil
_, err = Fscan(b, &r.i)
if err != nil {
return
}
var c int
c, _, err = b.ReadRune()
if err != nil {
if err == os.EOF {
err = nil
}
return
}
if c != '.' {
return
}
next := new(RecursiveInt)
err = scanInts(next, b)
if err == nil {
r.next = next
}
return
}
func makeInts(n int) []byte {
var buf bytes.Buffer
Fprintf(&buf, "1")
for i := 1; i < n; i++ {
Fprintf(&buf, ".%d", i+1)
}
return buf.Bytes()
}
func TestScanInts(t *testing.T) {
testScanInts(t, scanInts)
testScanInts(t, func(r *RecursiveInt, b *bytes.Buffer) (err os.Error) {
_, err = Fscan(b, r)
return
})
}
const intCount = 1000
func testScanInts(t *testing.T, scan func(*RecursiveInt, *bytes.Buffer) os.Error) {
r := new(RecursiveInt)
ints := makeInts(intCount)
buf := bytes.NewBuffer(ints)
err := scan(r, buf)
if err != nil {
t.Error("unexpected error", err)
}
i := 1
for ; r != nil; r = r.next {
if r.i != i {
t.Fatalf("bad scan: expected %d got %d", i, r.i)
}
i++
}
if i-1 != intCount {
t.Fatalf("bad scan count: expected %d got %d", intCount, i-1)
}
}
func BenchmarkScanInts(b *testing.B) {
b.ResetTimer()
ints := makeInts(intCount)
var r RecursiveInt
for i := b.N - 1; i >= 0; i-- {
buf := bytes.NewBuffer(ints)
b.StartTimer()
scanInts(&r, buf)
b.StopTimer()
}
}
func BenchmarkScanRecursiveInt(b *testing.B) {
b.ResetTimer()
ints := makeInts(intCount)
var r RecursiveInt
for i := b.N - 1; i >= 0; i-- {
buf := bytes.NewBuffer(ints)
b.StartTimer()
Fscan(buf, &r)
b.StopTimer()
}
}