V: .split().map() crashes

[zeddidragon]

V version: V 0.1.22 1f93bb5 (prebuilt from the site)
OS: Linux 4.7.0-040700rc3-generic x86_64

What did you do?

fn main() {
  str := '1,2,3'
  ints := str.split(',').map(it.int())
  for i in ints { print(i) }
}

What did you expect to see?
123

What did you see instead?

❯ v run test.v
warning: test.v:3:6: `ints` declared and not used
/tmp/v/test.tmp.c: In function ‘main__main’:
/tmp/v/test.tmp.c:3353:27: error: ‘string {aka struct string}’ has no member named ‘data’
  string it = ((string*)str.data)[i];
                           ...
(Use `v -g` to print the entire error message)

V error: C error. This should never happen.
Please create a GitHub issue: https://github.com/vlang/v/issues/new/choose

[hillerstorm]

map and filter are magic functions from what I can tell :) kinda limited use right now, the following is also not allowed at the moment (having .map or .filter in a for expression):

fn main() {
    str := '1,2,3,4'.split(',')
    for num in str.map(it.int()) {
        println(num)
    }
}

gives the following error:

$ v run test.v
/tmp/v/test.tmp.c: In function ‘main__main’:
/tmp/v/test.tmp.c:3278:1: error: expected expression before ‘array’
 array tmp2 = new_array(0, str .len, sizeof(int));
 ^~~~~
/tmp/v/test.tmp.c:3281:9: err...
(Use `v -g` to print the entire error message)

V error: C error. This should never happen. 
Please create a GitHub issue: https://github.com/vlang/v/issues/new/choose

I guess it has to do with how those functions are translated into for loops during compilation?

[spytheman]

Yes, for now map and filter better be used in isolation. That will be improved soon.
You can try this @zeddidragon :

fn main() {
  str := '1,2,3'
  splitted := str.split(',')
  ints := splitted.map(it.int())
  for i in ints { print(i) }
}

[zeddidragon]

That's what I ended up going with!

It's not so bad, but would be nice if the compiler said as much.

[Goodwine]

Minimal repro:

fn main() {
  [1].map(it + 1)
}

Output with -cg: pastebin

[alexesprit]

Should work now.

fn main() {
  str := '1,2,3'
  ints := str.split(',').map(it.int())
  for i in ints { print(i) }
}

$ vrun test4.v
123