3 ms·

You're usually better off using coroutines for this sort of asynchronous programming in Lua. There's a larger overlap between coroutines and continuations than

You're usually better off using coroutines for this sort of asynchronous programming in Lua. There's a larger overlap between coroutines and continuations than you'd think. Also, Lua doesn't have macros, at least not in the sense that Lisp and Prolog do. It just has eval.

scythe 17y ago
>You're usually better off using coroutines for this sort of asynchronous programming in Lua. Macros and coroutines don't solve the same problem here. Macros provide wrappers that make "callbacks" implicit; coroutines provide scheduling. >Also, Lua doesn't have macros, at least not in the sense that Lisp and Prolog do. It just has eval. http://metalua.luaforge.net/ http://metalua.luaforge.net/ I object!
- silentbicycle 17y ago
  I wondered if you meant Metalua. That's a different dialect, like OCaml vs. SML different. Standard Lua doesn't have macros, and the packages I've seen that add them (such as Luma, http://luaforge.net/projects/luma/ http://luaforge.net/projects/luma/) do so via eval. I haven't done that much with Metalua - I don't really feel that Lua's lacking macros is a major problem, really, though I like the author's views on metaprogramming ("Make it obvious when something interesting happens", etc.). I remember looking at it a year or so ago, but didn't get into it. I just gave it a quick stab at porting, and I remember why - "Prerequisites - a 32 bits, little endian CPU" - I tend to switch back and forth between a couple OSs and hardware platforms, and Lua's portability is a big bonus for me. Adding a couple ML-ish features to Lua would be tempting, though.
infinite8s 17y ago
Coroutines are just one-off continuations (ie you can only run them once).
- silentbicycle 17y ago
  Right. They can be used as one-shot continuations. It doesn't cover all use cases, but a good subset of them. There's a patch by Mike Pall to add coroutine copying for simulating multi-shot continuations, though.

scythe 17y ago

>You're usually better off using coroutines for this sort of asynchronous programming in Lua. Macros and coroutines don't solve the same problem here. Macros provide wrappers that make "callbacks" implicit; coroutines provide scheduling. >Also, Lua doesn't have macros, at least not in the sense that Lisp and Prolog do. It just has eval. http://metalua.luaforge.net/ http://metalua.luaforge.net/ I object!

silentbicycle 17y ago
I wondered if you meant Metalua. That's a different dialect, like OCaml vs. SML different. Standard Lua doesn't have macros, and the packages I've seen that add them (such as Luma, http://luaforge.net/projects/luma/ http://luaforge.net/projects/luma/) do so via eval. I haven't done that much with Metalua - I don't really feel that Lua's lacking macros is a major problem, really, though I like the author's views on metaprogramming ("Make it obvious when something interesting happens", etc.). I remember looking at it a year or so ago, but didn't get into it. I just gave it a quick stab at porting, and I remember why - "Prerequisites - a 32 bits, little endian CPU" - I tend to switch back and forth between a couple OSs and hardware platforms, and Lua's portability is a big bonus for me. Adding a couple ML-ish features to Lua would be tempting, though.

infinite8s 17y ago

Coroutines are just one-off continuations (ie you can only run them once).

silentbicycle 17y ago
Right. They can be used as one-shot continuations. It doesn't cover all use cases, but a good subset of them. There's a patch by Mike Pall to add coroutine copying for simulating multi-shot continuations, though.