78 lines
1.4 KiB
Go
78 lines
1.4 KiB
Go
package utf8
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import (
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"io"
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)
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// WriteRune writes a single UTF-8 encoded Unicode character and returns the number of bytes written.
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//
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// If ‘writer’ is nil then WriteRune will return an error that matches utf8.NilWriterError.
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//
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// Example
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//
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// Here is an example usage of WriteRune:
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//
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// n, err := utf8.WriteRune(writer, r)
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// if nil != err {
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//
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// switch err.(type) {
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// case utf8.NilWriterError:
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// //@TODO
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// default:
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// //TODO
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// }
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//
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// }
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func WriteRune(writer io.Writer, r rune) (int, error) {
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if nil == writer {
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return 0, errNilWriter
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}
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switch {
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case 127 >= r:
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var buffer [1]byte
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buffer[0] = byte(r)
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p := buffer[:]
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return writer.Write(p)
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case 0x7FF >= r:
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var buffer [2]byte
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buffer[0] = 0xC0 | byte((0x000007C0 & r) >> 6)
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buffer[1] = 0x80 | byte( 0x0000003F & r)
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p := buffer[:]
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return writer.Write(p)
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case 0xFFFF >= r:
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var buffer [3]byte
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buffer[0] = 0xE0 | byte((0x0000F000 & r) >> 12)
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buffer[1] = 0x80 | byte((0x00000FC0 & r) >> 6)
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buffer[2] = 0x80 | byte( 0x0000003F & r)
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p := buffer[:]
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return writer.Write(p)
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case 0x10FFFF >= r:
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var buffer [4]byte
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buffer[0] = 0xF0 | byte((0x001C0000 & r) >> 18)
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buffer[1] = 0x80 | byte((0x0003F000 & r) >> 12)
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buffer[2] = 0x80 | byte((0x00000FC0 & r) >> 6)
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buffer[3] = 0x80 | byte( 0x0000003F & r)
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p := buffer[:]
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return writer.Write(p)
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default:
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return 0, errInternalError
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}
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}
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