Error during build and empty window

[doberkofler]

I'm pretty sure I'm doing something wrong but cannot see what it is?

I tried to compile the counter.ts sample from the documentation:

import { App, Text, Button, VStack, State } from "perry/ui";

const count = State(0);

App("My Counter", () =>
  VStack([
    Text(`Count: ${count.get()}`),
    Button("Increment", () => {
      count.set(count.get() + 1);
    }),
    Button("Reset", () => {
      count.set(0);
    }),
  ])
);

During the compilation I see this:

perry compile counter.ts
Collecting modules...
Found 1 module(s): 1 native, 0 JavaScript
Generating code...

Module init order (0 modules):

Wrote object file: counter_ts.o
  Generating stubs for 9 missing symbols (0 data, 9 functions, 0 identity)
    - js_new_instance
    - js_await_js_promise
    - js_set_property
    - js_get_export
    - js_load_module
    - js_call_function
    - js_runtime_init
    - js_new_from_handle
    - js_create_callback
Linking (runtime-only)...
[strip-dedup] Processing: /usr/local/lib/libperry_ui_macos.a
[strip-dedup] ERROR: llvm-ar not found — cannot strip duplicates from libperry_ui_macos.a
[strip-dedup] FAILED for UI lib, using original: llvm-ar not found (install llvm-tools: rustup component add llvm-tools)
Linking perry/ui (native UI) from /usr/local/lib/libperry_ui_macos.a
ld: warning: no platform load command found in '/Users/doberkofler/MyShare/doberkofler/perry_example_new/counter_ts.o', assuming: macOS
ld: warning: no platform load command found in '/Users/doberkofler/MyShare/doberkofler/perry_example_new/_perry_stubs.o', assuming: macOS
Wrote executable: counter
Binary size: 0.6MB

The app window looks like this:

[proggeramlug]

Thanks for the report - the empty window is the real bug. The "Module init order (0 modules)" line in your output means your counter.ts got parsed but never registered for initialization, so App(...) never actually runs and you're seeing the bare AppKit window that the UI runtime brings up on its own. The 9 stubbed js_* symbols and the llvm-ar not found warning are both unrelated and harmless.

Could you share perry --version and your macOS version? I want to make sure I'm bisecting against the same build. I'll dig in as soon as I'm out of an LLVM-backend push I'm finishing today.

[doberkofler]

perry --version
perry 0.4.47

Platform: darwin x64
Release: 24.6.0

I actually only create the counter.ts file and nothing else.

[proggeramlug]

Reproduced locally and I owe you a correction - my earlier "Module init order (0 modules)" theory was wrong (that line is normal for a single-file program; the entry module is counted separately from that list).

The actual problem is a documentation bug - the docs in docs/src/getting-started/first-app.md teach an API that was never implemented. The real perry/ui surface is:

• App({ title, width, height, body }) - object-literal config, not App(title, renderFn). The codegen reads title/width/height/body off the first arg as an object; when you pass a string, every field comes back undefined and the second arg (your () => VStack(...) callback) is silently ignored. That's why the window came up empty.
• state.value (getter) and state.set(v) (setter) - there is no .get() method.
• VStack(spacing, [...children]) - first arg is the gap in points; VStack([...]) alone gets interpreted as spacing = <array garbage> with no children.

Here's the corrected counter - I verified it compiles to a 514K binary (vs 397K for the broken version, where dead-code elimination had wiped out most of the view tree):

import { App, Text, Button, VStack, State } from "perry/ui";

const count = State(0);

App({
  title: "My Counter",
  width: 400,
  height: 300,
  body: VStack(16, [
    Text(`Count: ${count.value}`),
    Button("Increment", () => {
      count.set(count.value + 1);
    }),
    Button("Reset", () => {
      count.set(0);
    }),
  ]),
});

I've just fixed all three examples in first-app.md (counter, todo, styled counter) on the branch I'm on - the fix will land in the next release. Thanks for catching this, and sorry for the detour on the first diagnosis.

[doberkofler]

Wow this was quick. It works now. Thank you and keep up the good work!