LuLu : Lua VM On Lua

>> Project Page, >> Japanese Page

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Download

• From Here! (Latest Release is: LuLu 0.05)

What's This?

LuLu is a Lua 5.1 VM implementation in Lua language itself.
It aims to be a concise, easily readable, and customizable LuaVM implemantation.

LuLu is originally written as the material for the blog series "Reading Lua VM".

Currently, LuLu consists of the interpreter of virtual machine instructions + the coroutine library. The implmentation of datatypes (strings, tables, etc) and most of the standard library functions are simply reusing the implementation of the host Lua environment.

Supported Features

• All VM Instructions
• Most of the stand library functions, including
  • io.* (forwarded to the host Lua)
  • file:* (forwarded to the host Lua)
  • string.* (forwarded to the host Lua, except string.dump)
  • math.* (forwarded to the host Lua)
  • coroutine.* (pure Lua implementation)

Currently Unsupported Features

• Metatables
  • (actually, all metamethods except __call should work under the metatable mechanism of the host Lua.)
• The following standard library functions:
  • dofile/load/loadfile/loadstring/string.dump
  • module/require/package.*
  • pcall/xpcall
  • debug.*

Performance Memo

Performance is not my first concern, so do not expect anything on it... :P

"Lua (C impl.)" vs "LuLu (Lua impl.)"

> lua test/fib.lua 24
        n       value   time    evals
plain   24      46368   0.05    150049
cached  24      46368   0       25

> lua lulu.lua test/fib.lua 24
        n       value   time    evals
plain   24      46368   6.088   150049
cached  24      46368   0       25

"LuLu" vs "LuLu on LuLu"

> lua lulu.lua test/fib.lua 18
        n       value   time    evals
plain   18      2584    0.49    8361
cached  18      2584    0.01    19

> lua lulu.lua lulu.lua test/fib.lua 18
        n       value   time    evals
plain   18      2584    30.013  8361
cached  18      2584    0.181   19

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hzkr <binhzkr _a_t_ gmail _d_o_t_ com>