Module vm 

Lua virtual machine — port of src/lvm.c (1899 lines, 32 functions).

This module implements:

• Number coercion helpers (tonumber_, flttointeger, tointegerns, tointeger)
• Numeric for-loop preparation and stepping (forlimit, forprep, floatforloop)
• Table get/set with metamethod chaining (finishget, finishset)
• String comparison respecting embedded NULs (l_strcmp)
• Relational operators: lessthan, lessequal, equalobj (with metamethods)
• String concatenation (concat)
• Object length operator (objlen)
• Integer arithmetic: idiv, mod, modf, shiftl
• Closure creation (pushclosure)
• Yield-resume bridge (finishOp)
• Main interpreter loop (execute) — the Lua bytecode dispatch engine.

Control flow note

The C source uses goto startfunc / goto returning / goto ret across labelled points in luaV_execute. These are modelled with Rust’s labelled loops ('startfunc, 'returning, 'dispatch) and continue/break on those labels. See inline PORT NOTE comments.

Enums

OpCode

TODO(phase-b): lua-types does not yet expose OpCode. Stubbed locally with all 5.4 opcodes so call sites in vm.rs/debug.rs resolve; the real numeric values and per-opcode mode flags live in lua-types/src/opcode.rs once translated.

Traits

InstructionExt

TODO(phase-b): Instruction accessor extension trait. The real per-mode decode helpers live in lua-types::opcode once translated. Stubbed locally so call sites resolve; bodies are inferred from lopcodes.h macro shapes.