in encoding/encoding.go [14:40]
func EncodeFloat(dst []byte, v float64, bits int) []byte {
if math.IsInf(v, 0) || math.IsNaN(v) {
panic(fmt.Sprintf("invalid float value: %s", strconv.FormatFloat(v, 'g', -1, bits)))
}
abs := math.Abs(v)
fmt := byte('f')
if abs != 0 {
if bits == 64 && (abs < 1e-6 || abs >= 1e21) || bits == 32 && (float32(abs) < 1e-6 || float32(abs) >= 1e21) {
fmt = 'e'
}
}
dst = strconv.AppendFloat(dst, v, fmt, -1, bits)
if fmt == 'e' {
// clean up e-09 to e-9
n := len(dst)
if n >= 4 && dst[n-4] == 'e' && dst[n-3] == '-' && dst[n-2] == '0' {
dst[n-2] = dst[n-1]
dst = dst[:n-1]
}
}
return dst
}