VM and compiler

VM

pd-vm executes compiled bytecode. Its runtime supports synchronous and asynchronous execution, real script call frames, first-class callable values, exported and queued callbacks, debugger-facing state, recording and replay, type metadata, regex caching, fuel, epoch interruption, and trace-JIT hooks.

Compiler

The compiler accepts RSS source and produces program metadata plus bytecode. The implementation separates source frontends, parsing, IR, type information, code generation, assembler support, host-call handling, and artifact encoding. Script functions and closures lower into function regions, callable prototypes, capture metadata, root bindings, and callvalue/ret control flow. Generic function references, captured and escaping closures, recursive calls, callable collections, and exported callback schemas are covered by compiler and runtime tests. The Callables and Closures reference describes the language surface.

Public versus internal contracts

The RSS language reference documents syntax and observable behavior. VMBC, debugger, host-function, callable/callback, and embedding contracts belong in reference pages. Parser layout, IR layout, VM frame handling, JIT trace representation, and compiler passes belong to contributor work.