After reading your answers, I was looking for Go gotchas and I find this. At the first look it looks promising, do you have opinion on it?
http://devs.cloudimmunity.com/gotchas-and-common-mistakes-in-go-golang/ Best, Kamil niedziela, 13 lutego 2022 o 23:58:14 UTC+1 Kamil Ziemian napisał(a): > Thank you Jason and Axel. I know that "nil" is predeclared identifier from > watching talk on YT "Understending nil" (or something like that) and know > that it can be redefined. But, due to my background I still struggle with > such things in Go. Old habits die hard, nothing more. > > Thank you Axel, you points are very helpful to me. They remained me title > of ones of Rob Pikes talks about Go "Simplicity is complicated". > > Best, > Kamil > piątek, 11 lutego 2022 o 21:21:03 UTC+1 axel.wa...@googlemail.com > napisał(a): > >> FWIW two useful aspects of this design are >> 1. It makes the language simpler, as we have fewer keywords and the >> grammar doesn't need to mention `int`/… everywhere >> 2. It makes it possible to extend the set of predeclared identifiers, >> without worrying about breakages. For example, we are adding a new `any` >> predeclared identifier in Go 1.18. This won't break any (hehe) code, as >> code which uses that identifier will just refer to the one it already >> declares. >> >> On Fri, Feb 11, 2022 at 8:38 PM Jason Phillips <jasonrya...@gmail.com> >> wrote: >> >>> In C and C++[1][2] "int" and "float" are reserved keywords and thus >>> can't be used as identifiers. In Go[3], "int" and "float64" are >>> "predeclared identifiers"[4] and can be redefined, just like any other >>> identifier. >>> >>> [1] - https://en.cppreference.com/w/c/keyword >>> [2] - https://en.cppreference.com/w/cpp/keyword >>> [3] - https://go.dev/ref/spec#Keywords >>> [4] - https://go.dev/ref/spec#Predeclared_identifiers >>> >>> On Friday, February 11, 2022 at 1:20:37 PM UTC-5 kziem...@gmail.com >>> wrote: >>> >>>> Hello, >>>> >>>> I have so background in C and C++ so was used to that you CAN'T define >>>> variable with the name of predefined types. But, in Go 1.17 (go version >>>> go1.17.7 linux/amd64) >>>> > package main >>>> > >>>> > import "fmt" >>>> > >>>> > func main() { >>>> > var int float64 = 2.5 >>>> > >>>> > fmt.Printf("int: %v, %T\n", int, int) >>>> > >>>> > // var varOne int = 1 >>>> > >>>> > // fmt.Printf("varOne: %v", varOne) >>>> > } >>>> this code compile and produce result >>>> > int: 2.5, float64 >>>> >>>> When you uncomment two lines in this example you will get error >>>> > int is not a type >>>> >>>> In Go 1.18beta2 (go version go1.18beta2 linux/amd64) >>>> > package main >>>> > >>>> > import ( >>>> > "fmt" >>>> > // "math" >>>> > ) >>>> > >>>> > type Constraint interface { >>>> > float64 >>>> > } >>>> > >>>> > func someFunction[uint8 Constraint](x uint8) uint8 { >>>> > x += uint8(1) >>>> > return x >>>> > } >>>> > >>>> > func main() { >>>> > var x float64 = 1 >>>> > >>>> > fmt.Printf("someFunction(%v): %v\n", x, someFunction(x)) >>>> > fmt.Printf("x type: %T\n", x) >>>> > fmt.Printf("someFunction(x) type: %T\n", someFunction(x)) >>>> > } >>>> this code compile and produce result >>>> > someFunction(1): 2 >>>> > x type: float64 >>>> > someFunction(x) type: float64 >>>> >>>> Can anyone tell me why this behavior is possible in Go? In the past I >>>> never write "var int int" because it is wicked and possible sinful, but >>>> syntax for generic functions make easier for me to produce such evil >>>> things. >>>> >>>> This is a bit too much shocking things for me for one day, I will be >>>> back tomorrow. >>>> >>>> Best, >>>> Kamil >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "golang-nuts" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to golang-nuts...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/78714732-cd31-49cf-a941-2ed228eb2b7fn%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/golang-nuts/78714732-cd31-49cf-a941-2ed228eb2b7fn%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/25d885e9-3ab9-47bd-8c0c-43ac99721132n%40googlegroups.com.
