Callback Examples

The callback examples prove that Kira can:

• generate a callback typedef binding from a C header
• pass a Kira @Native function as a real C ABI callback
• call through that callback in native code
• do the same across the hybrid runtime/native boundary
• keep mutable Kira-owned callback state behind an opaque userdata token

Native Example

Run:

kira run --backend llvm examples/callbacks

Current output:

callbacks
6
9
2
12

That comes from:

• a manifest under examples/callbacks/NativeLibs/callbacks.toml
• a generated module at examples/callbacks/callbacks.kira
• a Kira CounterState boxed with nativeState(...)
• an opaque token exported with nativeUserData(...)
• a native callback that mutates the boxed state with nativeRecover(...)

Hybrid Example

The repo also carries a hybrid callback proof in:

tests/pass/run/ffi_callback_hybrid/

That matters because it exercises:

• runtime entry execution
• native callback invocation
• runtime/native bridge marshalling

What This Proves

The callback examples are small, but they prove a lot of the current contract:

• generated callback typedefs are real Kira types
• RawPtr is the explicit user-data carrier
• nativeState(...) avoids forcing globals for callback state
• nativeRecover(any) is typed recovery, not a raw layout cast
• @FFI.Struct { layout: c; } remains separate from opaque callback state
• callback targets must match the generated signature exactly
• Kira does not invent closure capture semantics at the ABI boundary