bytes
Package bytes
Overview
Package bytes implements functions for the manipulation of byte slices. It is analogous to the facilities of the strings package.
Index
Examples
Package files
buffer.go bytes.go bytes_amd64.go bytes_decl.go reader.go
Constants
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.
const MinRead = 512
Variables
ErrTooLarge is passed to panic if memory cannot be allocated to store data in a buffer.
var ErrTooLarge = errors.New("bytes.Buffer: too large")
func CompareSource
func Compare(a, b []byte) int
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.
Example
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 } }
Example (Search)
package main import ( "bytes" "sort" ) func main() { // Binary search to find a matching byte slice. var needle []byte var haystack [][]byte // Assume sorted i := sort.Search(len(haystack), func(i int) bool { // Return haystack[i] >= needle. return bytes.Compare(haystack[i], needle) >= 0 }) if i < len(haystack) && bytes.Equal(haystack[i], needle) { // Found it! } }
func ContainsSource
func Contains(b, subslice []byte) bool
Contains reports whether subslice is within b.
Example
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(""))) }
func ContainsAnySource
func ContainsAny(b []byte, chars string) bool
ContainsAny reports whether any of the UTF-8-encoded Unicode code points in chars are within b.
func ContainsRuneSource
func ContainsRune(b []byte, r rune) bool
ContainsRune reports whether the Unicode code point r is within b.
func CountSource
func Count(s, sep []byte) int
Count counts the number of non-overlapping instances of sep in s. If sep is an empty slice, Count returns 1 + the number of Unicode code points in s.
Example
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 }
func EqualSource
func Equal(a, b []byte) bool
Equal returns a boolean reporting whether a and b are the same length and contain the same bytes. A nil argument is equivalent to an empty slice.
func EqualFoldSource
func EqualFold(s, t []byte) bool
EqualFold reports whether s and t, interpreted as UTF-8 strings, are equal under Unicode case-folding.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go"))) }
func FieldsSource
func Fields(s []byte) [][]byte
Fields splits the slice s around each instance of one or more consecutive white space characters, returning a slice of subslices of s or an empty list if s contains only white space.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("Fields are: %q", bytes.Fields([]byte(" foo bar baz "))) }
func FieldsFuncSource
func FieldsFunc(s []byte, f func(rune) bool) [][]byte
FieldsFunc interprets s as a sequence of UTF-8-encoded Unicode 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). If f does not return consistent results for a given c, FieldsFunc may crash.
Example
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)) }
func HasPrefixSource
func HasPrefix(s, prefix []byte) bool
HasPrefix tests whether the byte slice s begins with prefix.
Example
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(""))) }
func HasSuffixSource
func HasSuffix(s, suffix []byte) bool
HasSuffix tests whether the byte slice s ends with suffix.
Example
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(""))) }
func IndexSource
func Index(s, sep []byte) int
Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Println(bytes.Index([]byte("chicken"), []byte("ken"))) fmt.Println(bytes.Index([]byte("chicken"), []byte("dmr"))) }
func IndexAnySource
func IndexAny(s []byte, chars string) int
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.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Println(bytes.IndexAny([]byte("chicken"), "aeiouy")) fmt.Println(bytes.IndexAny([]byte("crwth"), "aeiouy")) }
func IndexByteSource
func IndexByte(s []byte, c byte) int
IndexByte returns the index of the first instance of c in s, or -1 if c is not present in s.
func IndexFuncSource
func IndexFunc(s []byte, f func(r rune) bool) int
IndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points. It returns the byte index in s of the first Unicode code point satisfying f(c), or -1 if none do.
Example
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)) }
func IndexRuneSource
func IndexRune(s []byte, r rune) int
IndexRune interprets s as a sequence of UTF-8-encoded Unicode 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.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Println(bytes.IndexRune([]byte("chicken"), 'k')) fmt.Println(bytes.IndexRune([]byte("chicken"), 'd')) }
func JoinSource
func Join(s [][]byte, sep []byte) []byte
Join concatenates the elements of s to create a new byte slice. The separator sep is placed between elements in the resulting slice.
Example
package main import ( "bytes" "fmt" ) func main() { s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")} fmt.Printf("%s", bytes.Join(s, []byte(", "))) }
func LastIndexSource
func LastIndex(s, sep []byte) int
LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
Example
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"))) }
func LastIndexAnySource
func LastIndexAny(s []byte, chars string) int
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.
func LastIndexByteSource
func LastIndexByte(s []byte, c byte) int
LastIndexByte returns the index of the last instance of c in s, or -1 if c is not present in s.
func LastIndexFuncSource
func LastIndexFunc(s []byte, f func(r rune) bool) int
LastIndexFunc interprets s as a sequence of UTF-8-encoded Unicode code points. It returns the byte index in s of the last Unicode code point satisfying f(c), or -1 if none do.
func MapSource
func Map(mapping func(r rune) rune, s []byte) []byte
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 string with no replacement. The characters in s and the output are interpreted as UTF-8-encoded Unicode code points.
Example
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", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher..."))) }
func RepeatSource
func Repeat(b []byte, count int) []byte
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.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2)) }
func ReplaceSource
func Replace(s, old, new []byte, n int) []byte
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.
Example
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)) }
func RunesSource
func Runes(s []byte) []rune
Runes returns a slice of runes (Unicode code points) equivalent to s.
func SplitSource
func Split(s, sep []byte) [][]byte
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.
Example
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"))) }
func SplitAfterSource
func SplitAfter(s, sep []byte) [][]byte
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.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%q\n", bytes.SplitAfter([]byte("a,b,c"), []byte(","))) }
func SplitAfterNSource
func SplitAfterN(s, sep []byte, n int) [][]byte
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
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%q\n", bytes.SplitAfterN([]byte("a,b,c"), []byte(","), 2)) }
func SplitNSource
func SplitN(s, sep []byte, n int) [][]byte
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
Example
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) }
func TitleSource
func Title(s []byte) []byte
Title returns a copy of s with all Unicode letters that begin words mapped to their title case.
BUG(rsc): The rule Title uses for word boundaries does not handle Unicode punctuation properly.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%s", bytes.Title([]byte("her royal highness"))) }
func ToLowerSource
func ToLower(s []byte) []byte
ToLower returns a copy of the byte slice s with all Unicode letters mapped to their lower case.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%s", bytes.ToLower([]byte("Gopher"))) }
func ToLowerSpecialSource
func ToLowerSpecial(c unicode.SpecialCase, s []byte) []byte
ToLowerSpecial returns a copy of the byte slice s with all Unicode letters mapped to their lower case, giving priority to the special casing rules.
func ToTitleSource
func ToTitle(s []byte) []byte
ToTitle returns a copy of the byte slice s with all Unicode letters mapped to their title case.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%s\n", bytes.ToTitle([]byte("loud noises"))) fmt.Printf("%s\n", bytes.ToTitle([]byte("хлеб"))) }
func ToTitleSpecialSource
func ToTitleSpecial(c unicode.SpecialCase, s []byte) []byte
ToTitleSpecial returns a copy of the byte slice s with all Unicode letters mapped to their title case, giving priority to the special casing rules.
func ToUpperSource
func ToUpper(s []byte) []byte
ToUpper returns a copy of the byte slice s with all Unicode letters mapped to their upper case.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%s", bytes.ToUpper([]byte("Gopher"))) }
func ToUpperSpecialSource
func ToUpperSpecial(c unicode.SpecialCase, s []byte) []byte
ToUpperSpecial returns a copy of the byte slice s with all Unicode letters mapped to their upper case, giving priority to the special casing rules.
func TrimSource
func Trim(s []byte, cutset string) []byte
Trim returns a subslice of s by slicing off all leading and trailing UTF-8-encoded Unicode code points contained in cutset.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! ")) }
func TrimFuncSource
func TrimFunc(s []byte, f func(r rune) bool) []byte
TrimFunc returns a subslice of s by slicing off all leading and trailing UTF-8-encoded Unicode code points c that satisfy f(c).
func TrimLeftSource
func TrimLeft(s []byte, cutset string) []byte
TrimLeft returns a subslice of s by slicing off all leading UTF-8-encoded Unicode code points contained in cutset.
func TrimLeftFuncSource
func TrimLeftFunc(s []byte, f func(r rune) bool) []byte
TrimLeftFunc returns a subslice of s by slicing off all leading UTF-8-encoded Unicode code points c that satisfy f(c).
func TrimPrefixSource
func TrimPrefix(s, prefix []byte) []byte
TrimPrefix returns s without the provided leading prefix string. If s doesn't start with prefix, s is returned unchanged.
Example
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) }
func TrimRightSource
func TrimRight(s []byte, cutset string) []byte
TrimRight returns a subslice of s by slicing off all trailing UTF-8-encoded Unicode code points that are contained in cutset.
func TrimRightFuncSource
func TrimRightFunc(s []byte, f func(r rune) bool) []byte
TrimRightFunc returns a subslice of s by slicing off all trailing UTF-8 encoded Unicode code points c that satisfy f(c).
func TrimSpaceSource
func TrimSpace(s []byte) []byte
TrimSpace returns a subslice of s by slicing off all leading and trailing white space, as defined by Unicode.
Example
package main import ( "bytes" "fmt" ) func main() { fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n"))) }
func TrimSuffixSource
func TrimSuffix(s, suffix []byte) []byte
TrimSuffix returns s without the provided trailing suffix string. If s doesn't end with suffix, s is returned unchanged.
Example
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) }
type BufferSource
A Buffer is a variable-sized buffer of bytes with Read and Write methods. The zero value for Buffer is an empty buffer ready to use.
type Buffer struct { // contains filtered or unexported fields }
Example
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) }
Example (Reader)
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) }
func NewBufferSource
func NewBuffer(buf []byte) *Buffer
NewBuffer creates and initializes a new Buffer using buf as its initial contents. It is intended to prepare a Buffer to read existing data. It can also be used to size 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.
func NewBufferStringSource
func NewBufferString(s string) *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.
func (*Buffer) BytesSource
func (b *Buffer) Bytes() []byte
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 Read, Write, Reset, or 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.
func (*Buffer) CapSource
func (b *Buffer) Cap() int
Cap returns the capacity of the buffer's underlying byte slice, that is, the total space allocated for the buffer's data.
func (*Buffer) GrowSource
func (b *Buffer) Grow(n int)
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.
func (*Buffer) LenSource
func (b *Buffer) Len() int
Len returns the number of bytes of the unread portion of the buffer; b.Len() == len(b.Bytes()).
func (*Buffer) NextSource
func (b *Buffer) Next(n int) []byte
Next returns a slice containing the next n bytes from the buffer, advancing the buffer as if the bytes had been returned by 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.
func (*Buffer) ReadSource
func (b *Buffer) Read(p []byte) (n int, err error)
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.
func (*Buffer) ReadByteSource
func (b *Buffer) ReadByte() (byte, error)
ReadByte reads and returns the next byte from the buffer. If no byte is available, it returns error io.EOF.
func (*Buffer) ReadBytesSource
func (b *Buffer) ReadBytes(delim byte) (line []byte, err error)
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.
func (*Buffer) ReadFromSource
func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error)
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.
func (*Buffer) ReadRuneSource
func (b *Buffer) ReadRune() (r rune, size int, err error)
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.
func (*Buffer) ReadStringSource
func (b *Buffer) ReadString(delim byte) (line string, err error)
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.
func (*Buffer) ResetSource
func (b *Buffer) Reset()
Reset resets the buffer to be empty, but it retains the underlying storage for use by future writes. Reset is the same as Truncate(0).
func (*Buffer) StringSource
func (b *Buffer) String() string
String returns the contents of the unread portion of the buffer as a string. If the Buffer is a nil pointer, it returns "<nil>".
func (*Buffer) TruncateSource
func (b *Buffer) Truncate(n int)
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.
func (*Buffer) UnreadByteSource
func (b *Buffer) UnreadByte() error
UnreadByte unreads the last byte returned by the most recent read operation. If write has happened since the last read, UnreadByte returns an error.
func (*Buffer) UnreadRuneSource
func (b *Buffer) UnreadRune() error
UnreadRune unreads the last rune returned by ReadRune. If the most recent read or write operation on the buffer was not a ReadRune, UnreadRune returns an error. (In this regard it is stricter than UnreadByte, which will unread the last byte from any read operation.)
func (*Buffer) WriteSource
func (b *Buffer) Write(p []byte) (n int, err error)
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.
func (*Buffer) WriteByteSource
func (b *Buffer) WriteByte(c byte) error
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.
func (*Buffer) WriteRuneSource
func (b *Buffer) WriteRune(r rune) (n int, err error)
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.
func (*Buffer) WriteStringSource
func (b *Buffer) WriteString(s string) (n int, err error)
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.
func (*Buffer) WriteToSource
func (b *Buffer) WriteTo(w io.Writer) (n int64, err error)
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.
type ReaderSource
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.
type Reader struct { // contains filtered or unexported fields }
func NewReaderSource
func NewReader(b []byte) *Reader
NewReader returns a new Reader reading from b.
func (*Reader) LenSource
func (r *Reader) Len() int
Len returns the number of bytes of the unread portion of the slice.
func (*Reader) ReadSource
func (r *Reader) Read(b []byte) (n int, err error)
func (*Reader) ReadAtSource
func (r *Reader) ReadAt(b []byte, off int64) (n int, err error)
func (*Reader) ReadByteSource
func (r *Reader) ReadByte() (byte, error)
func (*Reader) ReadRuneSource
func (r *Reader) ReadRune() (ch rune, size int, err error)
func (*Reader) ResetSource
func (r *Reader) Reset(b []byte)
Reset resets the Reader to be reading from b.
func (*Reader) SeekSource
func (r *Reader) Seek(offset int64, whence int) (int64, error)
Seek implements the io.Seeker interface.
func (*Reader) SizeSource
func (r *Reader) Size() int64
Size returns the original length of the underlying byte slice. Size is the number of bytes available for reading via ReadAt. The returned value is always the same and is not affected by calls to any other method.
func (*Reader) UnreadByteSource
func (r *Reader) UnreadByte() error
func (*Reader) UnreadRuneSource
func (r *Reader) UnreadRune() error
func (*Reader) WriteToSource
func (r *Reader) WriteTo(w io.Writer) (n int64, err error)
WriteTo implements the io.WriterTo interface.
Bugs
-
☞
The rule Title uses for word boundaries does not handle Unicode punctuation properly.
© Google, Inc.
Licensed under the Creative Commons Attribution License 3.0.
https://golang.org/pkg/bytes/