You will need a build tag for that.
For example:
In a separate file, define the build tag
```
// +build debug
package mypkg
func init() {
Debug = true
}
```
Then, in other files, use the tag
```
package mypkg
var Debug bool
func DoWork() {
if Debug {
// perform validation
}
}
```
When building with validation, call "go build -tags debug"
On Thursday, March 31, 2022 at 1:40:07 AM UTC+7 toon....@gmail.com wrote:
> I like to check the preconditions of a function explicitly by means of
> code (instead of only documenting them). Of course this incurs a
> time-penalty.
>
> When being extremely cautious every function in a call-chain will always
> check its preconditions. But for a function down in the call-chain, the
> precondition checks of all its callers might already guarantee that its own
> pre-condition checks will never be violated. And thus these checks down the
> chain are unnecessary cpu cycles.
>
> Do there exist tools/methods to detect this and auto-remove these
> precondition checks?
>
> For example:
> the function Muladd below verifies that all arrays have the same length.
> Muladd relies on two functions to perform the `mul` and the `add` and each
> of these will also verify their respective preconditions explicitly. Given
> these functions are not exported and given these functions are only called
> by `muladd`, the compiler might be able to determine that the precondition
> checks are guaranteed to be valid and can thus be removed.
>
> https://go.dev/play/p/92isKKx-vYx
>
> package main
>
> import "fmt"
>
> func main() {
> x := []float64{1.0, 2.0, 3.0}
> y := []float64{1.0, 2.0, 3.0}
> z := []float64{1.0, 2.0, 3.0}
> Muladd(x, y, z)
> fmt.Printf("%+v", x)
> }
>
> func Muladd(x []float64, y []float64, z []float64) error {
> // check precondition (but unnecessary if only called by Muladd)
> if len(x) != len(y) || len(x) != len(z) {
> return fmt.Errorf("slices have different lengths %d vs %d vs %d",
> len(x), len(y), len(z))
> }
> mul(x, y)
> add(x, z)
> return nil
> }
>
> func mul(x []float64, y []float64) error {
> // check precondition
> if len(x) != len(y) {
> return fmt.Errorf("slices have different lengths %d vs %d",
> len(x), len(y))
> }
>
> for i := range x {
> x[i] *= y[i]
> }
> return nil
> }
>
> func add(x []float64, y []float64) error {
> // check precondition
> if len(x) != len(y) {
> return fmt.Errorf("slices have different lengths %d vs %d",
> len(x), len(y))
> }
>
> for i := range x {
> x[i] += y[i]
> }
> return nil
> }
>
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