go float zero division compiler error

Question

How does this behaviour sense? wouln't it make mor sense to just print an compiler warning instead of an error?

func main() {
var y float64 = 0.0
var x float64 = 4.0 / y
fmt.Println(x)
}

+Inf

func main() {
var x float64 = 4.0 / 0.0
fmt.Println(x)
}

prog.go:9:22: division by zero

Constants aren't floats. There is no infinity constant, hence the error. — Passer By, Jul 25 '18 at 06:52
Why? Division by Zero doesn't make sense. If you want infinity, type math.Inf(1). — Peter, Jul 25 '18 at 06:56
Dividing b a literal 0 is a malformed program, thus a compiler error. — Volker, Jul 25 '18 at 07:00
but shouldn't I be able to compile this? Rust for examle compiles with compiler warnings. — jonathan-dev, Jul 25 '18 at 07:01
warnings are at best a code debt that all coders will have to ignore. Either it's OK, or it's an error. — Denys Séguret, Jul 25 '18 at 07:04
so it is kind of related to the philosophy of go. That there is one way to do certain things (go fmt)? — jonathan-dev, Jul 25 '18 at 07:09

Denys Séguret · Accepted Answer · 2018-07-25T11:49:56.500

Golang numeric consts are special. They're not directly mapped to any IEEE754 float type, and they're not able to store infinities or -0 for example.

From the documentation:

Numeric constants represent exact values of arbitrary precision and do not overflow. Consequently, there are no constants denoting the IEEE-754 negative zero, infinity, and not-a-number values.

This choice brings some power, as it reduces overflowing in constants:

var x float64 = 1e1000 / 1e999 // yes, this is 10

If you need an infinity value you may do

var x float64 = math.Inf(1)

go float zero division compiler error

1 Answers1