b, err := appendCompact(b, src, false)
	dst.Write(b)
	return err
}

func appendCompact(dst, src []byte, escape bool) ([]byte, error) {
	origLen := len(dst)
	scan := newScanner()
	defer freeScanner(scan)
	start := 0
	for i, c := range src {
		if escape && (c == '<' || c == '>' || c == '&') {
			if start < i {
				dst = append(dst, src[start:i]...)
			}

// before diving into the scanner itself.

import (
	"strconv"
	"sync"
)

// Valid reports whether data is a valid JSON encoding.
func Valid(data []byte) bool {
	scan := newScanner()
	defer freeScanner(scan)
	return checkValid(data, scan) == nil
}

// checkValid verifies that data is valid JSON-encoded data.
// scan is passed in for use by checkValid to avoid an allocation.
// checkValid returns nil or a SyntaxError.