Getting error when instantiating a set: "invalid operation: cannot index mapset.NewSet (value of type func(s ...interface{}) mapset.Set)"

[pcgeek86]

• Golang 1.20
• MacOS
• VSCode

Repro Steps

myset := mapset.NewSet[string]()

Actual Result

invalid operation: cannot index mapset.NewSet (value of type func(s ...interface{}) mapset.Set)

Expected Result

New set should be instantiated.

[deckarep]

@pcgeek86 - Hi, this is pretty surprising if this is somehow broken on Go 1.20 and I'll be investigating this today. In the meantime, if anyone else experiences this with 1.20 please +1 this issue.

[pcgeek86]

Thanks, I'm pretty new to Go. I was just copying the example from the README, and was surprised that it was throwing the error.

[deckarep]

So far I can't reproduce the issue you are seeing...here is a complete code snippet running go1.20

package main

import (
    "fmt"
    mapset "github.com/deckarep/golang-set/v2"
    "runtime"
)

func main() {
    // Create a string-based set of required classes.
    req := mapset.NewSet[string]()
    req.Add("cooking")
    req.Add("english")
    req.Add("math")
    req.Add("biology")

    fmt.Printf("Go version: %s\n", runtime.Version())
    fmt.Println("size: ", req.Cardinality())

    req.Each(func(x string) bool {
        fmt.Println("->", x)
        return false
    })
}

Output:

Go version: go1.20.1
size:  4
-> cooking
-> english
-> math
-> biology

[deckarep]

You mentioned you are new to Go, a couple of things to make sure:

1. That you are properly importing the correct version of the Set v2
2. That you are using Go modules correctly which is the recommended way to use dependencies for awhile now: go get github.com/deckarep/golang-set/v2
3. That your Go environment is properly setup, perhaps try pulling in other dependencies to make sure things are solid.

[pcgeek86]

I just created a new folder / module and was able to repro the issue.

> go mod init trevortest
> go get github.com/deckarep/golang-set

Go.mod

NOTE: I solved the issue by appending /v2 to the module name. Thanks for pointing that out! I had incorrectly assumed the module name was just the GitHub repo path.

[deckarep]

Glad it's resolved!