Involved Source Filesbuffer.go Package bytes implements functions for the manipulation of byte slices.
It is analogous to the facilities of the [strings] package.reader.go
Code Examples
package main
import (
"bytes"
"fmt"
"os"
)
func main() {
var b bytes.Buffer // A Buffer needs no initialization.
b.Write([]byte("Hello "))
fmt.Fprintf(&b, "world!")
b.WriteTo(os.Stdout)
}
package main
import (
"bytes"
"os"
"strconv"
)
func main() {
var buf bytes.Buffer
for i := 0; i < 4; i++ {
b := buf.AvailableBuffer()
b = strconv.AppendInt(b, int64(i), 10)
b = append(b, ' ')
buf.Write(b)
}
os.Stdout.Write(buf.Bytes())
}
package main
import (
"bytes"
"os"
)
func main() {
buf := bytes.Buffer{}
buf.Write([]byte{'h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd'})
os.Stdout.Write(buf.Bytes())
}
package main
import (
"bytes"
"fmt"
)
func main() {
buf1 := bytes.NewBuffer(make([]byte, 10))
buf2 := bytes.NewBuffer(make([]byte, 0, 10))
fmt.Println(buf1.Cap())
fmt.Println(buf2.Cap())
}
package main
import (
"bytes"
"fmt"
)
func main() {
var b bytes.Buffer
b.Grow(64)
bb := b.Bytes()
b.Write([]byte("64 bytes or fewer"))
fmt.Printf("%q", bb[:b.Len()])
}
package main
import (
"bytes"
"fmt"
)
func main() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
fmt.Printf("%d", b.Len())
}
package main
import (
"bytes"
"fmt"
)
func main() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
fmt.Printf("%s\n", b.Next(2))
fmt.Printf("%s\n", b.Next(2))
fmt.Printf("%s", b.Next(2))
}
package main
import (
"bytes"
"fmt"
)
func main() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
rdbuf := make([]byte, 1)
n, err := b.Read(rdbuf)
if err != nil {
panic(err)
}
fmt.Println(n)
fmt.Println(b.String())
fmt.Println(string(rdbuf))
}
package main
import (
"bytes"
"fmt"
)
func main() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
c, err := b.ReadByte()
if err != nil {
panic(err)
}
fmt.Println(c)
fmt.Println(b.String())
}
package main
import (
"bytes"
"encoding/base64"
"io"
"os"
)
func main() {
// A Buffer can turn a string or a []byte into an io.Reader.
buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
dec := base64.NewDecoder(base64.StdEncoding, buf)
io.Copy(os.Stdout, dec)
}
package main
import (
"bytes"
"fmt"
)
func main() {
b := []byte("abc")
clone := bytes.Clone(b)
fmt.Printf("%s\n", clone)
clone[0] = 'd'
fmt.Printf("%s\n", b)
fmt.Printf("%s\n", clone)
}
package main
import (
"bytes"
)
func main() {
// Interpret Compare's result by comparing it to zero.
var a, b []byte
if bytes.Compare(a, b) < 0 {
// a less b
}
if bytes.Compare(a, b) <= 0 {
// a less or equal b
}
if bytes.Compare(a, b) > 0 {
// a greater b
}
if bytes.Compare(a, b) >= 0 {
// a greater or equal b
}
// Prefer Equal to Compare for equality comparisons.
if bytes.Equal(a, b) {
// a equal b
}
if !bytes.Equal(a, b) {
// a not equal b
}
}
package main
import (
"bytes"
"slices"
)
func main() {
// Binary search to find a matching byte slice.
var needle []byte
var haystack [][]byte // Assume sorted
_, found := slices.BinarySearchFunc(haystack, needle, bytes.Compare)
if found {
// Found it!
}
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.Contains([]byte("seafood"), []byte("foo")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("bar")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("")))
fmt.Println(bytes.Contains([]byte(""), []byte("")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "fÄo!"))
fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "去是伟大的."))
fmt.Println(bytes.ContainsAny([]byte("I like seafood."), ""))
fmt.Println(bytes.ContainsAny([]byte(""), ""))
}
package main
import (
"bytes"
"fmt"
)
func main() {
f := func(r rune) bool {
return r >= 'a' && r <= 'z'
}
fmt.Println(bytes.ContainsFunc([]byte("HELLO"), f))
fmt.Println(bytes.ContainsFunc([]byte("World"), f))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'f'))
fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'ö'))
fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '大'))
fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '!'))
fmt.Println(bytes.ContainsRune([]byte(""), '@'))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.Count([]byte("cheese"), []byte("e")))
fmt.Println(bytes.Count([]byte("five"), []byte(""))) // before & after each rune
}
package main
import (
"bytes"
"fmt"
)
func main() {
show := func(s, sep string) {
before, after, found := bytes.Cut([]byte(s), []byte(sep))
fmt.Printf("Cut(%q, %q) = %q, %q, %v\n", s, sep, before, after, found)
}
show("Gopher", "Go")
show("Gopher", "ph")
show("Gopher", "er")
show("Gopher", "Badger")
}
package main
import (
"bytes"
"fmt"
)
func main() {
show := func(s, sep string) {
after, found := bytes.CutPrefix([]byte(s), []byte(sep))
fmt.Printf("CutPrefix(%q, %q) = %q, %v\n", s, sep, after, found)
}
show("Gopher", "Go")
show("Gopher", "ph")
}
package main
import (
"bytes"
"fmt"
)
func main() {
show := func(s, sep string) {
before, found := bytes.CutSuffix([]byte(s), []byte(sep))
fmt.Printf("CutSuffix(%q, %q) = %q, %v\n", s, sep, before, found)
}
show("Gopher", "Go")
show("Gopher", "er")
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.Equal([]byte("Go"), []byte("Go")))
fmt.Println(bytes.Equal([]byte("Go"), []byte("C++")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("Fields are: %q", bytes.Fields([]byte(" foo bar baz ")))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
f := func(c rune) bool {
return !unicode.IsLetter(c) && !unicode.IsNumber(c)
}
fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte(" foo1;bar2,baz3..."), f))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("Go")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("C")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("go")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("O")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("Ami")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.Index([]byte("chicken"), []byte("ken")))
fmt.Println(bytes.Index([]byte("chicken"), []byte("dmr")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.IndexAny([]byte("chicken"), "aeiouy"))
fmt.Println(bytes.IndexAny([]byte("crwth"), "aeiouy"))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.IndexByte([]byte("chicken"), byte('k')))
fmt.Println(bytes.IndexByte([]byte("chicken"), byte('g')))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
f := func(c rune) bool {
return unicode.Is(unicode.Han, c)
}
fmt.Println(bytes.IndexFunc([]byte("Hello, 世界"), f))
fmt.Println(bytes.IndexFunc([]byte("Hello, world"), f))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.IndexRune([]byte("chicken"), 'k'))
fmt.Println(bytes.IndexRune([]byte("chicken"), 'd'))
}
package main
import (
"bytes"
"fmt"
)
func main() {
s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
fmt.Printf("%s", bytes.Join(s, []byte(", ")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("rodent")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "MüQp"))
fmt.Println(bytes.LastIndexAny([]byte("go 地鼠"), "地大"))
fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "z,!."))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('g')))
fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('r')))
fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('z')))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsLetter))
fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsPunct))
fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsNumber))
}
package main
import (
"bytes"
"fmt"
)
func main() {
rot13 := func(r rune) rune {
switch {
case r >= 'A' && r <= 'Z':
return 'A' + (r-'A'+13)%26
case r >= 'a' && r <= 'z':
return 'a' + (r-'a'+13)%26
}
return r
}
fmt.Printf("%s\n", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("k"), []byte("ky"), 2))
fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("oink"), []byte("moo"), -1))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s\n", bytes.ReplaceAll([]byte("oink oink oink"), []byte("oink"), []byte("moo")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
rs := bytes.Runes([]byte("go gopher"))
for _, r := range rs {
fmt.Printf("%#U\n", r)
}
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%q\n", bytes.Split([]byte("a,b,c"), []byte(",")))
fmt.Printf("%q\n", bytes.Split([]byte("a man a plan a canal panama"), []byte("a ")))
fmt.Printf("%q\n", bytes.Split([]byte(" xyz "), []byte("")))
fmt.Printf("%q\n", bytes.Split([]byte(""), []byte("Bernardo O'Higgins")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%q\n", bytes.SplitAfter([]byte("a,b,c"), []byte(",")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%q\n", bytes.SplitAfterN([]byte("a,b,c"), []byte(","), 2))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%q\n", bytes.SplitN([]byte("a,b,c"), []byte(","), 2))
z := bytes.SplitN([]byte("a,b,c"), []byte(","), 0)
fmt.Printf("%q (nil = %v)\n", z, z == nil)
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s", bytes.Title([]byte("her royal highness")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
str := []byte("AHOJ VÝVOJÁRİ GOLANG")
totitle := bytes.ToLowerSpecial(unicode.AzeriCase, str)
fmt.Println("Original : " + string(str))
fmt.Println("ToLower : " + string(totitle))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s\n", bytes.ToTitle([]byte("loud noises")))
fmt.Printf("%s\n", bytes.ToTitle([]byte("хлеб")))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
str := []byte("ahoj vývojári golang")
totitle := bytes.ToTitleSpecial(unicode.AzeriCase, str)
fmt.Println("Original : " + string(str))
fmt.Println("ToTitle : " + string(totitle))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
str := []byte("ahoj vývojári golang")
totitle := bytes.ToUpperSpecial(unicode.AzeriCase, str)
fmt.Println("Original : " + string(str))
fmt.Println("ToUpper : " + string(totitle))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("abc"), []byte("\uFFFD")))
fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("a\xffb\xC0\xAFc\xff"), []byte("")))
fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("\xed\xa0\x80"), []byte("abc")))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsLetter)))
fmt.Println(string(bytes.TrimFunc([]byte("\"go-gopher!\""), unicode.IsLetter)))
fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsPunct)))
fmt.Println(string(bytes.TrimFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Print(string(bytes.TrimLeft([]byte("453gopher8257"), "0123456789")))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher"), unicode.IsLetter)))
fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher!"), unicode.IsPunct)))
fmt.Println(string(bytes.TrimLeftFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
}
package main
import (
"bytes"
"fmt"
)
func main() {
var b = []byte("Goodbye,, world!")
b = bytes.TrimPrefix(b, []byte("Goodbye,"))
b = bytes.TrimPrefix(b, []byte("See ya,"))
fmt.Printf("Hello%s", b)
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Print(string(bytes.TrimRight([]byte("453gopher8257"), "0123456789")))
}
package main
import (
"bytes"
"fmt"
"unicode"
)
func main() {
fmt.Println(string(bytes.TrimRightFunc([]byte("go-gopher"), unicode.IsLetter)))
fmt.Println(string(bytes.TrimRightFunc([]byte("go-gopher!"), unicode.IsPunct)))
fmt.Println(string(bytes.TrimRightFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
}
package main
import (
"bytes"
"fmt"
)
func main() {
fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
}
package main
import (
"bytes"
"os"
)
func main() {
var b = []byte("Hello, goodbye, etc!")
b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
b = bytes.TrimSuffix(b, []byte("gopher"))
b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
os.Stdout.Write(b)
}
Package-Level Type Names (total 2)
/* sort by: | */
A Buffer is a variable-sized buffer of bytes with [Buffer.Read] and [Buffer.Write] methods.
The zero value for Buffer is an empty buffer ready to use. Available returns how many bytes are unused in the buffer. AvailableBuffer returns an empty buffer with b.Available() capacity.
This buffer is intended to be appended to and
passed to an immediately succeeding [Buffer.Write] call.
The buffer is only valid until the next write operation on b. Bytes returns a slice of length b.Len() holding the unread portion of the buffer.
The slice is valid for use only until the next buffer modification (that is,
only until the next call to a method like [Buffer.Read], [Buffer.Write], [Buffer.Reset], or [Buffer.Truncate]).
The slice aliases the buffer content at least until the next buffer modification,
so immediate changes to the slice will affect the result of future reads. Cap returns the capacity of the buffer's underlying byte slice, that is, the
total space allocated for the buffer's data. Grow grows the buffer's capacity, if necessary, to guarantee space for
another n bytes. After Grow(n), at least n bytes can be written to the
buffer without another allocation.
If n is negative, Grow will panic.
If the buffer can't grow it will panic with [ErrTooLarge]. Len returns the number of bytes of the unread portion of the buffer;
b.Len() == len(b.Bytes()). Next returns a slice containing the next n bytes from the buffer,
advancing the buffer as if the bytes had been returned by [Buffer.Read].
If there are fewer than n bytes in the buffer, Next returns the entire buffer.
The slice is only valid until the next call to a read or write method. Read reads the next len(p) bytes from the buffer or until the buffer
is drained. The return value n is the number of bytes read. If the
buffer has no data to return, err is io.EOF (unless len(p) is zero);
otherwise it is nil. ReadByte reads and returns the next byte from the buffer.
If no byte is available, it returns error io.EOF. ReadBytes reads until the first occurrence of delim in the input,
returning a slice containing the data up to and including the delimiter.
If ReadBytes encounters an error before finding a delimiter,
it returns the data read before the error and the error itself (often io.EOF).
ReadBytes returns err != nil if and only if the returned data does not end in
delim. ReadFrom reads data from r until EOF and appends it to the buffer, growing
the buffer as needed. The return value n is the number of bytes read. Any
error except io.EOF encountered during the read is also returned. If the
buffer becomes too large, ReadFrom will panic with [ErrTooLarge]. ReadRune reads and returns the next UTF-8-encoded
Unicode code point from the buffer.
If no bytes are available, the error returned is io.EOF.
If the bytes are an erroneous UTF-8 encoding, it
consumes one byte and returns U+FFFD, 1. ReadString reads until the first occurrence of delim in the input,
returning a string containing the data up to and including the delimiter.
If ReadString encounters an error before finding a delimiter,
it returns the data read before the error and the error itself (often io.EOF).
ReadString returns err != nil if and only if the returned data does not end
in delim. Reset resets the buffer to be empty,
but it retains the underlying storage for use by future writes.
Reset is the same as [Buffer.Truncate](0). String returns the contents of the unread portion of the buffer
as a string. If the [Buffer] is a nil pointer, it returns "<nil>".
To build strings more efficiently, see the strings.Builder type. Truncate discards all but the first n unread bytes from the buffer
but continues to use the same allocated storage.
It panics if n is negative or greater than the length of the buffer. UnreadByte unreads the last byte returned by the most recent successful
read operation that read at least one byte. If a write has happened since
the last read, if the last read returned an error, or if the read read zero
bytes, UnreadByte returns an error. UnreadRune unreads the last rune returned by [Buffer.ReadRune].
If the most recent read or write operation on the buffer was
not a successful [Buffer.ReadRune], UnreadRune returns an error. (In this regard
it is stricter than [Buffer.UnreadByte], which will unread the last byte
from any read operation.) Write appends the contents of p to the buffer, growing the buffer as
needed. The return value n is the length of p; err is always nil. If the
buffer becomes too large, Write will panic with [ErrTooLarge]. WriteByte appends the byte c to the buffer, growing the buffer as needed.
The returned error is always nil, but is included to match [bufio.Writer]'s
WriteByte. If the buffer becomes too large, WriteByte will panic with
[ErrTooLarge]. WriteRune appends the UTF-8 encoding of Unicode code point r to the
buffer, returning its length and an error, which is always nil but is
included to match [bufio.Writer]'s WriteRune. The buffer is grown as needed;
if it becomes too large, WriteRune will panic with [ErrTooLarge]. WriteString appends the contents of s to the buffer, growing the buffer as
needed. The return value n is the length of s; err is always nil. If the
buffer becomes too large, WriteString will panic with [ErrTooLarge]. WriteTo writes data to w until the buffer is drained or an error occurs.
The return value n is the number of bytes written; it always fits into an
int, but it is int64 to match the io.WriterTo interface. Any error
encountered during the write is also returned.
*Buffer : compress/flate.Reader
*Buffer : expvar.Var
*Buffer : fmt.Stringer
*Buffer : image/jpeg.Reader
*Buffer : internal/bisect.Writer
*Buffer : io.ByteReader
*Buffer : io.ByteScanner
*Buffer : io.ByteWriter
*Buffer : io.Reader
*Buffer : io.ReaderFrom
*Buffer : io.ReadWriter
*Buffer : io.RuneReader
*Buffer : io.RuneScanner
*Buffer : io.StringWriter
*Buffer : io.Writer
*Buffer : io.WriterTo
func NewBuffer(buf []byte) *Buffer
func NewBufferString(s string) *Buffer
func encoding/json.Compact(dst *Buffer, src []byte) error
func encoding/json.HTMLEscape(dst *Buffer, src []byte)
func encoding/json.Indent(dst *Buffer, src []byte, prefix, indent string) error
func go/types.WriteExpr(buf *Buffer, x ast.Expr)
func go/types.WriteSignature(buf *Buffer, sig *types.Signature, qf types.Qualifier)
func go/types.WriteType(buf *Buffer, typ types.Type, qf types.Qualifier)
A Reader implements the io.Reader, io.ReaderAt, io.WriterTo, io.Seeker,
io.ByteScanner, and io.RuneScanner interfaces by reading from
a byte slice.
Unlike a [Buffer], a Reader is read-only and supports seeking.
The zero value for Reader operates like a Reader of an empty slice. Len returns the number of bytes of the unread portion of the
slice. Read implements the [io.Reader] interface. ReadAt implements the [io.ReaderAt] interface. ReadByte implements the [io.ByteReader] interface. ReadRune implements the [io.RuneReader] interface. Reset resets the [Reader] to be reading from b. Seek implements the [io.Seeker] interface. Size returns the original length of the underlying byte slice.
Size is the number of bytes available for reading via [Reader.ReadAt].
The result is unaffected by any method calls except [Reader.Reset]. UnreadByte complements [Reader.ReadByte] in implementing the [io.ByteScanner] interface. UnreadRune complements [Reader.ReadRune] in implementing the [io.RuneScanner] interface. WriteTo implements the [io.WriterTo] interface.
*Reader : compress/flate.Reader
*Reader : image/jpeg.Reader
*Reader : io.ByteReader
*Reader : io.ByteScanner
*Reader : io.Reader
*Reader : io.ReaderAt
*Reader : io.ReadSeeker
*Reader : io.RuneReader
*Reader : io.RuneScanner
*Reader : io.Seeker
*Reader : io.WriterTo
func NewReader(b []byte) *Reader
Package-Level Functions (total 55)
Clone returns a copy of b[:len(b)].
The result may have additional unused capacity.
Clone(nil) returns nil.
Compare returns an integer comparing two byte slices lexicographically.
The result will be 0 if a == b, -1 if a < b, and +1 if a > b.
A nil argument is equivalent to an empty slice.
Contains reports whether subslice is within b.
ContainsAny reports whether any of the UTF-8-encoded code points in chars are within b.
ContainsFunc reports whether any of the UTF-8-encoded code points r within b satisfy f(r).
ContainsRune reports whether the rune is contained in the UTF-8-encoded byte slice b.
Count counts the number of non-overlapping instances of sep in s.
If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
Cut slices s around the first instance of sep,
returning the text before and after sep.
The found result reports whether sep appears in s.
If sep does not appear in s, cut returns s, nil, false.
Cut returns slices of the original slice s, not copies.
CutPrefix returns s without the provided leading prefix byte slice
and reports whether it found the prefix.
If s doesn't start with prefix, CutPrefix returns s, false.
If prefix is the empty byte slice, CutPrefix returns s, true.
CutPrefix returns slices of the original slice s, not copies.
CutSuffix returns s without the provided ending suffix byte slice
and reports whether it found the suffix.
If s doesn't end with suffix, CutSuffix returns s, false.
If suffix is the empty byte slice, CutSuffix returns s, true.
CutSuffix returns slices of the original slice s, not copies.
Equal reports whether a and b
are the same length and contain the same bytes.
A nil argument is equivalent to an empty slice.
EqualFold reports whether s and t, interpreted as UTF-8 strings,
are equal under simple Unicode case-folding, which is a more general
form of case-insensitivity.
Fields interprets s as a sequence of UTF-8-encoded code points.
It splits the slice s around each instance of one or more consecutive white space
characters, as defined by unicode.IsSpace, returning a slice of subslices of s or an
empty slice if s contains only white space.
FieldsFunc interprets s as a sequence of UTF-8-encoded code points.
It splits the slice s at each run of code points c satisfying f(c) and
returns a slice of subslices of s. If all code points in s satisfy f(c), or
len(s) == 0, an empty slice is returned.
FieldsFunc makes no guarantees about the order in which it calls f(c)
and assumes that f always returns the same value for a given c.
HasPrefix reports whether the byte slice s begins with prefix.
HasSuffix reports whether the byte slice s ends with suffix.
Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
IndexAny interprets s as a sequence of UTF-8-encoded Unicode code points.
It returns the byte index of the first occurrence in s of any of the Unicode
code points in chars. It returns -1 if chars is empty or if there is no code
point in common.
IndexByte returns the index of the first instance of c in b, or -1 if c is not present in b.
IndexFunc interprets s as a sequence of UTF-8-encoded code points.
It returns the byte index in s of the first Unicode
code point satisfying f(c), or -1 if none do.
IndexRune interprets s as a sequence of UTF-8-encoded code points.
It returns the byte index of the first occurrence in s of the given rune.
It returns -1 if rune is not present in s.
If r is utf8.RuneError, it returns the first instance of any
invalid UTF-8 byte sequence.
Join concatenates the elements of s to create a new byte slice. The separator
sep is placed between elements in the resulting slice.
LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
LastIndexAny interprets s as a sequence of UTF-8-encoded Unicode code
points. It returns the byte index of the last occurrence in s of any of
the Unicode code points in chars. It returns -1 if chars is empty or if
there is no code point in common.
LastIndexByte returns the index of the last instance of c in s, or -1 if c is not present in s.
LastIndexFunc interprets s as a sequence of UTF-8-encoded code points.
It returns the byte index in s of the last Unicode
code point satisfying f(c), or -1 if none do.
Map returns a copy of the byte slice s with all its characters modified
according to the mapping function. If mapping returns a negative value, the character is
dropped from the byte slice with no replacement. The characters in s and the
output are interpreted as UTF-8-encoded code points.
NewBuffer creates and initializes a new [Buffer] using buf as its
initial contents. The new [Buffer] takes ownership of buf, and the
caller should not use buf after this call. NewBuffer is intended to
prepare a [Buffer] to read existing data. It can also be used to set
the initial size of the internal buffer for writing. To do that,
buf should have the desired capacity but a length of zero.
In most cases, new([Buffer]) (or just declaring a [Buffer] variable) is
sufficient to initialize a [Buffer].
NewBufferString creates and initializes a new [Buffer] using string s as its
initial contents. It is intended to prepare a buffer to read an existing
string.
In most cases, new([Buffer]) (or just declaring a [Buffer] variable) is
sufficient to initialize a [Buffer].
Repeat returns a new byte slice consisting of count copies of b.
It panics if count is negative or if the result of (len(b) * count)
overflows.
Replace returns a copy of the slice s with the first n
non-overlapping instances of old replaced by new.
If old is empty, it matches at the beginning of the slice
and after each UTF-8 sequence, yielding up to k+1 replacements
for a k-rune slice.
If n < 0, there is no limit on the number of replacements.
ReplaceAll returns a copy of the slice s with all
non-overlapping instances of old replaced by new.
If old is empty, it matches at the beginning of the slice
and after each UTF-8 sequence, yielding up to k+1 replacements
for a k-rune slice.
Runes interprets s as a sequence of UTF-8-encoded code points.
It returns a slice of runes (Unicode code points) equivalent to s.
Split slices s into all subslices separated by sep and returns a slice of
the subslices between those separators.
If sep is empty, Split splits after each UTF-8 sequence.
It is equivalent to SplitN with a count of -1.
To split around the first instance of a separator, see Cut.
SplitAfter slices s into all subslices after each instance of sep and
returns a slice of those subslices.
If sep is empty, SplitAfter splits after each UTF-8 sequence.
It is equivalent to SplitAfterN with a count of -1.
SplitAfterN slices s into subslices after each instance of sep and
returns a slice of those subslices.
If sep is empty, SplitAfterN splits after each UTF-8 sequence.
The count determines the number of subslices to return:
n > 0: at most n subslices; the last subslice will be the unsplit remainder.
n == 0: the result is nil (zero subslices)
n < 0: all subslices
SplitN slices s into subslices separated by sep and returns a slice of
the subslices between those separators.
If sep is empty, SplitN splits after each UTF-8 sequence.
The count determines the number of subslices to return:
n > 0: at most n subslices; the last subslice will be the unsplit remainder.
n == 0: the result is nil (zero subslices)
n < 0: all subslices
To split around the first instance of a separator, see Cut.
Title treats s as UTF-8-encoded bytes and returns a copy with all Unicode letters that begin
words mapped to their title case.
Deprecated: The rule Title uses for word boundaries does not handle Unicode
punctuation properly. Use golang.org/x/text/cases instead.
ToLower returns a copy of the byte slice s with all Unicode letters mapped to
their lower case.
ToLowerSpecial treats s as UTF-8-encoded bytes and returns a copy with all the Unicode letters mapped to their
lower case, giving priority to the special casing rules.
ToTitle treats s as UTF-8-encoded bytes and returns a copy with all the Unicode letters mapped to their title case.
ToTitleSpecial treats s as UTF-8-encoded bytes and returns a copy with all the Unicode letters mapped to their
title case, giving priority to the special casing rules.
ToUpper returns a copy of the byte slice s with all Unicode letters mapped to
their upper case.
ToUpperSpecial treats s as UTF-8-encoded bytes and returns a copy with all the Unicode letters mapped to their
upper case, giving priority to the special casing rules.
ToValidUTF8 treats s as UTF-8-encoded bytes and returns a copy with each run of bytes
representing invalid UTF-8 replaced with the bytes in replacement, which may be empty.
Trim returns a subslice of s by slicing off all leading and
trailing UTF-8-encoded code points contained in cutset.
TrimFunc returns a subslice of s by slicing off all leading and trailing
UTF-8-encoded code points c that satisfy f(c).
TrimLeft returns a subslice of s by slicing off all leading
UTF-8-encoded code points contained in cutset.
TrimLeftFunc treats s as UTF-8-encoded bytes and returns a subslice of s by slicing off
all leading UTF-8-encoded code points c that satisfy f(c).
TrimPrefix returns s without the provided leading prefix string.
If s doesn't start with prefix, s is returned unchanged.
TrimRight returns a subslice of s by slicing off all trailing
UTF-8-encoded code points that are contained in cutset.
TrimRightFunc returns a subslice of s by slicing off all trailing
UTF-8-encoded code points c that satisfy f(c).
TrimSpace returns a subslice of s by slicing off all leading and
trailing white space, as defined by Unicode.
TrimSuffix returns s without the provided trailing suffix string.
If s doesn't end with suffix, s is returned unchanged.
Package-Level Variables (only one)
ErrTooLarge is passed to panic if memory cannot be allocated to store data in a buffer.
Package-Level Constants (only one)
MinRead is the minimum slice size passed to a Read call by
[Buffer.ReadFrom]. As long as the [Buffer] has at least MinRead bytes beyond
what is required to hold the contents of r, ReadFrom will not grow the
underlying buffer.
The pages are generated with Goldsv0.7.0-preview. (GOOS=linux GOARCH=amd64)
Golds is a Go 101 project developed by Tapir Liu.
PR and bug reports are welcome and can be submitted to the issue list.
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