Method demo

examples/demo.php:1844–1873

()

class ClosureParamInferenceDemo
{
    public function demo(): void
    {
        $src = new ScaffoldingClosureParamInference();

        // $p is inferred as Pen from map's callable(TValue, TKey) signature
        $src->items->map(fn($p) => $p->write());

        // Closure body
        $src->items->each(function ($pen) {
            $pen->write();                // resolves to Pen
        });

        // Explicit type hint takes precedence over inference
        $src->items->map(fn(Pencil $p) => $p->sketch());

        // $this in callable param resolves to receiver, not current class
        $pipeline = new ScaffoldingPipeline();
        $pipeline->when(true, function ($pipe) {
            $pipe->send('data');          // resolves to ScaffoldingPipeline, not this demo class
        });

        // Arrow function variant
        $pipeline->tap(fn($p) => $p->through([]));

        // Function-level @template callable inference
        // array_any(@param array<TKey, TValue>, @param callable(TValue, TKey): bool)
        // $item is inferred as Pen from the array's element type via template substitution
        $holder = new ScaffoldingTemplateCallableHolder();
        array_any($holder->tools, fn($item) => $item->write() !== '');
    }
}