1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
package main
import (
"errors"
"fmt"
)
type TemperatureUnit int
const (
Celcius TemperatureUnit = iota
Kelvin
Fahrenheit
)
var TemperatureUnits = []string{"°C", "°K", "°F"}
func ParseTemperatureUnit(s string) (TemperatureUnit, error) {
// Each case corresponds to a value in UnitStrings().
switch s {
case "°C":
return Celcius, nil
case "°K":
return Kelvin, nil
case "°F":
return Fahrenheit, nil
default:
return *new(TemperatureUnit), errors.New(fmt.Sprintf("invalid unit: '%s'", s))
}
}
type Temperature struct {
Val float32
Unit TemperatureUnit
}
func (t Temperature) AsUnit(u TemperatureUnit) (float32, error) {
// Convert to celcius
var c float32
switch t.Unit {
case Celcius:
c = t.Val
case Kelvin:
c = t.Val - 272.15
case Fahrenheit:
c = (t.Val - 32.0) * (5.0 / 9.0)
}
// Convert to desired unit
switch u {
case Celcius:
return c, nil
case Kelvin:
return c + 272.15, nil
case Fahrenheit:
return c*(9.0/5.0) + 32.0, nil
default:
return 0, errors.New(fmt.Sprintf("invalid unit: '%v'", u))
}
}
|