53 lines
888 B
Go
53 lines
888 B
Go
package utf8s
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import (
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"io"
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)
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// A utf8s.RuneScanner implements the io.RuneScanner interface by reading from an io.Reader.
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type RuneScanner struct {
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reader io.Reader
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prevRune rune
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prevSize int
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prevErr error
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peeked bool
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}
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func NewRuneScanner(reader io.Reader) *RuneScanner {
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return &RuneScanner{
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reader: reader,
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}
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}
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func (receiver *RuneScanner) ReadRune() (rune, int, error) {
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if nil == receiver {
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return RuneError, 0, errNilReceiver
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}
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reader := receiver.reader
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if nil == reader {
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return RuneError, 0, errNilReader
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}
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if receiver.peeked {
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receiver.peeked = false
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} else {
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receiver.prevRune, receiver.prevSize, receiver.prevErr = ReadRune(reader)
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}
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return receiver.prevRune, receiver.prevSize, receiver.prevErr
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}
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func (receiver *RuneScanner) UnreadRune() error {
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if nil == receiver {
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return errNilReceiver
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}
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receiver.peeked = true
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return nil
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}
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