Writing native plugins

Implement %native classes in C: declare them in .loth, implement them in a shared library, and let the VM bind and validate the two.

What you need

• A built toolchain: make and make libs.
• A C compiler that can produce shared libraries (cc -shared -fPIC).

The running example

The track builds one plugin: a stateful Counter class plus a CounterUtil singleton registered by the same library.

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The example exercises every mechanism the chapters describe: language-visible fields, a GC root held in the handle, a language exception thrown from C, a blocking call, and a two-class library.

Chapters

• 01 How native classes work — declaration vs implementation, descriptors, registration, validation.
• 02 Your first plugin — the Counter, step by step.
• 03 Data in and out — NativeCtx, typed accessors, strings, varargs, slots.
• 04 Fields and constructors — language-visible fields and native construction.
• 05 Memory and GC — the root contract, gc_scan, finalize, value lifetimes.
• 06 Exceptions and callbacks — vm_throw, the exception pipeline, calling back into the language.
• 07 Advanced metadata — multi-class libraries, interfaces, slots, dynamic loading, native-info.
• 08 Concurrency and operations — blocking, platform locks, thread safety, pitfalls.