Looping through generic enum at comptime with $for causes v-analyzer to crash

[jeffbdavenport]

Describe the bug

Using $for comptime keyword anywhere in any file causes a crash

Expected Behavior

It doesn't crash

Current Behavior

It crashed.

Reproduction Steps

pub struct Game[T] {
  levels map[T]int
}

pub fn Game.new[T]() &Game[T] {
    mut levels := map[T]int{}
    $for data in T.values {
        levels[data.value] = 0
    }
    return &Game[T]{ levels: levels }
}

enum Levels {
    one
}

fn main() {
  game := Game.new[Levels]()
  println('${game}')
}

Possible Solution

No response

Additional Information/Context

No response

Environment details (v doctor output)

jeff@DESKTOP-N30T80W ~$ v doctor

V full version	V 0.4.10 87d3a1d27229b64896cf3e22bab4822e1b75fb9a.87d3a1d
OS	linux, Ubuntu 24.04.2 LTS
Processor	16 cpus, 64bit, little endian, Intel(R) Core(TM) i7-10870H CPU @ 2.20GHz
Memory	18.91GB/31.22GB
V executable	/opt/v/v
V last modified time	2025-04-23 05:26:36
V home dir	OK, value: /opt/v
VMODULES	OK, value: /home/jeff/.vmodules
VTMP	OK, value: /tmp/v_1000
Current working dir	OK, value: /home/jeff
Git version	git version 2.43.0
V git status	weekly.2025.16-34-g87d3a1d2
.git/config present	true
cc version	cc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
gcc version	gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
clang version	Homebrew clang version 15.0.7
tcc version	tcc version 0.9.28rc 2025-02-13 HEAD@f8bd136d (x86_64 Linux)
tcc git status	thirdparty-linux-amd64 696c1d84
emcc version	N/A
glibc version	ldd (Ubuntu GLIBC 2.39-0ubuntu8.4) 2.39

Editor name

VS Code

v-analyzer Version

v-analyzer version 0.0.3-beta.1.a796f25

VS Code Extension Version

vosca.vscode-v-analyzer-0.0.3

[JalonSolov]

The example code doesn't compile for me - too many errors...

x.v:15:1: warning: unused variable: `game`
   13 | }
   14 | 
   15 | game := Game(Levels).new()
      | ~~~~
x.v:15:14: error: undefined ident: `Levels`
   13 | }
   14 | 
   15 | game := Game(Levels).new()
      |              ~~~~~~
x.v:15:14: error: expression does not return a value so it cannot be cast
   13 | }
   14 | 
   15 | game := Game(Levels).new()
      |              ~~~~~~
x.v:15:9: error: cannot cast `void` to struct
   13 | }
   14 | 
   15 | game := Game(Levels).new()
      |         ~~~~~~~~~~~~
x.v:15:22: error: unknown method or field: `Game.new`
   13 | }
   14 | 
   15 | game := Game(Levels).new()
      |                      ~~~~~
x.v:15:6: error: assignment mismatch: 1 variable but `new()` returns 0 values
   13 | }
   14 | 
   15 | game := Game(Levels).new()
      |      ~~

[jeffbdavenport]

@JalonSolov Thanks for your patience. I was just providing pseudo code, I didn't think anyone would try to run it. I have updated the code so it can be run now.

[JalonSolov]

If we can't run your example, how are we supposed to duplicate the problem, so we can try to track it down and fix it?

At any rate, with the corrected example code, it works fine on my system (or at least doesn't crash):

$ v run x.v
&Game[Levels]{
    levels: {one: 0}
}
$

[jeffbdavenport]

@JalonSolov Maybe you misunderstood the issue? The issue is not that the code doesn't run. The issue is that v-analyzer crashes when trying to index the file. At that point, no files can be analyzed anymore. The program runs just fine with V. This is why I didn't think it mattered to run the file as that is not the issue.

[JalonSolov]

My apologies. This showed up amongst other issues related to V itself, and the title didn't say v-analyzer, so I was checking V operation.

That aside, it is still always better to have real code rather than pseudo code which could cause different reactions in v-analyzer than real code.

Something that would still need to be fixed, but that's an important detail to know when looking for the problem.

[jeffbdavenport]

Agreed