Lua equivalent to Python dis()?

Question

In Python you have the ability to view the compiled bytecode of a user-defined function using dis.

Is there a builtin equivalent to this for Lua?

It would really useful!

Answer 1

Chunkspy might be what you're looking for. Quoting from the site:

ChunkSpy is a tool to disassemble a Lua 5 binary chunk into a verbose listing that can then be studied. Its output bears a resemblance to the output listing of assemblers. I wanted something that can tell me in great detail what goes on inside a Lua binary chunk file, not just the instructions. It is intended to be a tool for learning Lua internals as well.

Answer 2

The luac utility that comes with standard lua can create an assembly listing from Lua source using its -l option. For example, compiling from source on stdin:

C:...> echo a=b | luac -l -

main  (3 instructions, 12 bytes at 00334C30)
0+ params, 2 slots, 0 upvalues, 0 locals, 2 constants, 0 functions
        1       [1]     GETGLOBAL       0 -2    ; b
        2       [1]     SETGLOBAL       0 -1    ; a
        3       [1]     RETURN          0 1
C:...> 

Answer 3

You can also use luac -l to compile a lua file and output the disassembly.

Answer 4

There is also lbci, a bytecode inspector library.