34 lines
540 B
Go
34 lines
540 B
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"strconv"
|
|
)
|
|
|
|
type ScientificNotationValue float64
|
|
|
|
func (s *ScientificNotationValue) UnmarshalText(text []byte) error {
|
|
f, err := strconv.ParseFloat(string(text), 64)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
*s = ScientificNotationValue(f)
|
|
return nil
|
|
}
|
|
|
|
func (s *ScientificNotationValue) MarshalText() ([]byte, error) {
|
|
v := float64(*s)
|
|
exp := 0
|
|
for v < 1 {
|
|
v *= 10
|
|
exp -= 1
|
|
}
|
|
for v >= 10 {
|
|
v /= 10
|
|
exp += 1
|
|
}
|
|
res := fmt.Sprintf("%.3f", v)
|
|
res += fmt.Sprintf("e%d", exp)
|
|
return []byte(res), nil
|
|
}
|