1package humanize
2
3import (
4 "bytes"
5 "math"
6 "math/big"
7 "strconv"
8 "strings"
9)
10
11// Comma produces a string form of the given number in base 10 with
12// commas after every three orders of magnitude.
13//
14// e.g. Comma(834142) -> 834,142
15func Comma(v int64) string {
16 sign := ""
17
18 // Min int64 can't be negated to a usable value, so it has to be special cased.
19 if v == math.MinInt64 {
20 return "-9,223,372,036,854,775,808"
21 }
22
23 if v < 0 {
24 sign = "-"
25 v = 0 - v
26 }
27
28 parts := []string{"", "", "", "", "", "", ""}
29 j := len(parts) - 1
30
31 for v > 999 {
32 parts[j] = strconv.FormatInt(v%1000, 10)
33 switch len(parts[j]) {
34 case 2:
35 parts[j] = "0" + parts[j]
36 case 1:
37 parts[j] = "00" + parts[j]
38 }
39 v = v / 1000
40 j--
41 }
42 parts[j] = strconv.Itoa(int(v))
43 return sign + strings.Join(parts[j:], ",")
44}
45
46// Commaf produces a string form of the given number in base 10 with
47// commas after every three orders of magnitude.
48//
49// e.g. Commaf(834142.32) -> 834,142.32
50func Commaf(v float64) string {
51 buf := &bytes.Buffer{}
52 if v < 0 {
53 buf.Write([]byte{'-'})
54 v = 0 - v
55 }
56
57 comma := []byte{','}
58
59 parts := strings.Split(strconv.FormatFloat(v, 'f', -1, 64), ".")
60 pos := 0
61 if len(parts[0])%3 != 0 {
62 pos += len(parts[0]) % 3
63 buf.WriteString(parts[0][:pos])
64 buf.Write(comma)
65 }
66 for ; pos < len(parts[0]); pos += 3 {
67 buf.WriteString(parts[0][pos : pos+3])
68 buf.Write(comma)
69 }
70 buf.Truncate(buf.Len() - 1)
71
72 if len(parts) > 1 {
73 buf.Write([]byte{'.'})
74 buf.WriteString(parts[1])
75 }
76 return buf.String()
77}
78
79// CommafWithDigits works like the Commaf but limits the resulting
80// string to the given number of decimal places.
81//
82// e.g. CommafWithDigits(834142.32, 1) -> 834,142.3
83func CommafWithDigits(f float64, decimals int) string {
84 return stripTrailingDigits(Commaf(f), decimals)
85}
86
87// BigComma produces a string form of the given big.Int in base 10
88// with commas after every three orders of magnitude.
89func BigComma(b *big.Int) string {
90 sign := ""
91 if b.Sign() < 0 {
92 sign = "-"
93 b.Abs(b)
94 }
95
96 athousand := big.NewInt(1000)
97 c := (&big.Int{}).Set(b)
98 _, m := oom(c, athousand)
99 parts := make([]string, m+1)
100 j := len(parts) - 1
101
102 mod := &big.Int{}
103 for b.Cmp(athousand) >= 0 {
104 b.DivMod(b, athousand, mod)
105 parts[j] = strconv.FormatInt(mod.Int64(), 10)
106 switch len(parts[j]) {
107 case 2:
108 parts[j] = "0" + parts[j]
109 case 1:
110 parts[j] = "00" + parts[j]
111 }
112 j--
113 }
114 parts[j] = strconv.Itoa(int(b.Int64()))
115 return sign + strings.Join(parts[j:], ",")
116}