1package graphql
 2
 3import (
 4	"fmt"
 5	"io"
 6	"strconv"
 7)
 8
 9const encodeHex = "0123456789ABCDEF"
10
11func MarshalString(s string) Marshaler {
12	return WriterFunc(func(w io.Writer) {
13		start := 0
14		io.WriteString(w, `"`)
15
16		for i, c := range s {
17			if c < 0x20 || c == '\\' || c == '"' {
18				io.WriteString(w, s[start:i])
19
20				switch c {
21				case '\t':
22					io.WriteString(w, `\t`)
23				case '\r':
24					io.WriteString(w, `\r`)
25				case '\n':
26					io.WriteString(w, `\n`)
27				case '\\':
28					io.WriteString(w, `\\`)
29				case '"':
30					io.WriteString(w, `\"`)
31				default:
32					io.WriteString(w, `\u00`)
33					w.Write([]byte{encodeHex[c>>4], encodeHex[c&0xf]})
34				}
35
36				start = i + 1
37			}
38		}
39
40		io.WriteString(w, s[start:])
41		io.WriteString(w, `"`)
42	})
43}
44func UnmarshalString(v interface{}) (string, error) {
45	switch v := v.(type) {
46	case string:
47		return v, nil
48	case int:
49		return strconv.Itoa(v), nil
50	case float64:
51		return fmt.Sprintf("%f", v), nil
52	case bool:
53		if v {
54			return "true", nil
55		} else {
56			return "false", nil
57		}
58	case nil:
59		return "null", nil
60	default:
61		return "", fmt.Errorf("%T is not a string", v)
62	}
63}