Script Language Wierdness

[BugRoger]

I'm having trouble understanding what's going on here:

scenes = hkknx.GroupWriteNotify("0/5/0")
scene = <- scenes
println(fmt.Sprintf("%T", scene))
println(scene)
println(scene+1)
println(scene[0])
println(scene[0]+1)


[]uint8  // odd, isn't this supposed to be byte[] according to the docs?
[40]     // where did the 41 go? first bit was eaten somewhere
[40 1]   // wierd. in the golang playground this throws: mismatched types []uint8 and int. Some autoboxing going on here
40       // Ok
1        // What?

This happens when I write a 41 to 0/5/0 which is DPT18.001.

Some of the usual if err := hkknx.GroupWrite(); err != nil {} idioms also throw syntax errors. The script language is not quite Golang is it? ;)

[brutella]

The script language is not quite Golang is it? ;)

You're right, it's not quite like Golang but very similar.

[]uint8 // odd, isn't this supposed to be byte[] according to the docs?

byte is actually an uint8.
see https://golang.org/src/builtin/builtin.go?s=2701:2718#L78

[40] // where did the 41 go? first bit was eaten somewhere

The KNX protocol defines that scene numbers start at value 0. But for users they start at 1.
Scene 41 is actually the byte value 40. 😉

[40 1] // wierd. in the golang playground this throws: mismatched types []uint8 and int. Some autoboxing going on here

The scripts lets you append values to an array using the +-operator like this.

var array = [10]
println(array + 1) // [10, 1]

Note that this is not possible in Go. In Go you would have to use the append method.

var array = []uint8{10}
println(append(array, 1)) // [10, 1]

40 // Ok

See above.

1 // What?

This seems weird for me as well. 🤔

Some of the usual if err := hkknx.GroupWrite(); err != nil {} idioms also throw syntax errors.

First, the := assignment operator is not supported. You have to use = instead.
Secondly, the scripting language doesn't allow variable definitions inside an if-statement.

[BugRoger]

Thanks for your reply. I made it work. It just confused me that there's no way to do a + 1.

if (scene[0] == 40) { // This is really 41 on the KNX bus
  ...
}