# Platform Notes

> USearch for Zig

### What This Binding Does Not Expose

- The sequence, matrix and geospatial indexes the C library declares, which this module does not bind yet.
- `usearch_cpu_class_name` and `usearch_gpu_class_name`, since no type here names a CPU or GPU class.
- The numeric `usearch_version` triple; `usearch.version()` answers the library's version string instead.

### Design

- __A thin layer over the C ABI.__
  Every name follows `c/usearch/`: a C verb `usearch_dense_<verb>` is a `<verb>` here, in camelCase, and enums mirror C enums, never strings.
  Every type is its C name without `usearch_` and `_t`, a verb's argument structure becomes its `Dense*Config`, and every wrapper's documentation names the C symbol it calls or says it is binding-only.
- __The receiver chooses, the verb stays.__
  The index runs a verb on the calling thread, `on(executor)` blocks on an executor, and `deferred(executor, &call)` submits it, all with the same arguments.
- __Deferred calls use the language's own idioms.__
  `status` polls through `usearch_outcome_status`, `wait` blocks through `usearch_outcome_wait`, and with no `async` left in Zig, waiting is how a result is collected.
- __No life of its own.__
  The binding starts no threads and keeps no queues; releasing a `Deferred` rides `defer call.deinit()`, which waits for the call first.
- __Arenas are lent and reused, never shared.__
  Every output whose length scales with the call lands in an arena the caller passes; each view carries the arena's generation, and reads after the arena serves another call answer `Error.Uninitialized`.
- __Nothing costs anything until it is used.__
  Submitting a call allocates nothing, and an arena allocates only when a call writes into it.
- __Layouts are declared, not translated.__
  An `extern struct` already has the ABI's layout and an `enum(c_int)` its width, so no call site casts what a translated header would hand back as `c_uint` or `?*anyopaque`.
- __Callbacks are `comptime` functions.__
  Predicates, progress handlers and value lookups wrap a function known at compile time, so the trampoline crossing the boundary is generated per call site and nothing is boxed.