cmd/compile: error message for bad case in switch should suggest select #4697
Comments
Currently if you use a send statement in a switch you get this:
$ cat z.go
package main
func main() {
var c chan int
switch {
case c <- 0:
}
}
$ go tool 6g z.go
z.go:6: send statement c <- 0 used as value; use select for non-blocking send
But it doesn't mean what you would expect and has nothing to do with switches. Actually
the message is inherited from a pre r56 version
(http://golang.org/doc/devel/weekly.html#2011-02-01) and it's rather confusing. I
suggest that if someone fixes this issue the special message is removed.
|
rsc
changed the title
|
I've mailed https://go-review.googlesource.com/37392. |
|
CL https://golang.org/cl/37392 mentions this issue. |
|
As mentioned by @griesemer in CL 37392, the compiler giving such suggestions is a slippery slope, so for now let's keep the issue and the CL open in case new ideas come up. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
When writing a switch statement like this: package main func main() { ch := make(chan int) switch { case <-ch: default: } } The compiler error is: prog.go:6: invalid case <-ch in switch (mismatched types int and bool) This is a correct message, but for cases where the user is doing channel operations in the cases, can we add to the parenthetical "; did you mean select?" ? It shouldn't be displayed if the type of the channel expression is bool, obviously.The text was updated successfully, but these errors were encountered: