You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: decode.go
    path of file: ./repos/fabio/vendor/github.com/go-logfmt/logfmt
    
    the code of the file until where you have to start completion: package logfmt

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"unicode/utf8"
)

// A Decoder reads and decodes logfmt records from an input stream.
type Decoder struct {
	pos     int
	key     []byte
	value   []byte
	lineNum int
	s       *bufio.Scanner
	err     error
}

// NewDec
    
func (dec *Decoder) ScanKeyval() bool {
	dec.key, dec.value = nil, nil
	if dec.err != nil {
		return false
	}

	line := dec.s.Bytes()

	// garbage
	for p, c := range line[dec.pos:] {
		if c > ' ' {
			dec.pos += p
			goto key
		}
	}
	dec.pos = len(line)
	return false

key:
	const invalidKeyError = "invalid key"

	start, multibyte := dec.pos, false
	for p, c := range line[dec.pos:] {
		switch {
		case c == '=':
			dec.pos += p
			if dec.pos > start {
				dec.key = line[start:dec.pos]
				if multibyte && bytes.ContainsRune(dec.key, utf8.RuneError) {
					dec.syntaxError(invalidKeyError)
					return false
				}
			}
			if dec.key == nil {
				dec.unexpectedByte(c)
				return false
			}
			goto equal
		case c == '"':
			dec.pos += p
			dec.unexpectedByte(c)
			return false
		case c <= ' ':
			dec.pos += p
			if dec.pos > start {
				dec.key = line[start:dec.pos]
				if multibyte && bytes.ContainsRune(dec.key, utf8.RuneError) {
					dec.syntaxError(invalidKeyError)
					return false
				}
			}
			return true
		case c >= utf8.RuneSelf:
			multibyte = true
		}
	}
	dec.pos = len(line)
	if dec.pos > start {
		dec.key = line[start:dec.pos]
		if multibyte && bytes.ContainsRune(dec.key, utf8.RuneError) {
			dec.syntaxError(invalidKeyError)
			return false
		}
	}
	return true

equal:
	dec.pos++
	if dec.pos >= len(line) {
		return true
	}
	switch c := line[dec.pos]; {
	case c <= ' ':
		return true
	case c == '"':
		goto qvalue
	}

	// value
	start = dec.pos
	for p, c := range line[dec.pos:] {
		switch {
		case c == '=' || c == '"':
			dec.pos += p
			dec.unexpectedByte(c)
			return false
		case c <= ' ':
			dec.pos += p
			if dec.pos > start {
				dec.value = line[start:dec.pos]
			}
			return true
		}
	}
	dec.pos = len(line)
	if dec.pos > start {
		dec.value = line[start:dec.pos]
	}
	return true

qvalue:
	const (
		untermQuote  = "unterminated quoted value"
		invalidQuote = "invalid quoted value"
	)

	hasEsc, esc := false, false
	start = dec.pos
	for p, c := range line[dec.pos+1:] {
		switch {
		case esc:
			esc = false
		case c == '\\':
			hasEsc, esc = true, true
		case c == '"':
			dec.pos += p + 2
			if hasEsc {
				v, ok := unquoteBytes(line[start:dec.pos])
				if !ok {
					dec.syntaxError(invalidQuote)
					return false
				}
				dec.value = v
			} else {
				start++
				end := dec.pos - 1
				if end > start {
					dec.value = line[start:end]
				}
			}
			return true
		}
	}
	dec.pos = len(line)
	dec.syntaxError(untermQuote)
	return false
}