8 ms·

People that use lua, what do you use it for and why did you pick lua?

Doctor_Fegg 7y ago
My OpenStreetMap tag processing pipeline: OSRM, osm2pgsql and tilemaker all allow you to write tag-mangling scripts in Lua.
cobbzilla 7y ago
It’s great for embedded scripts in Redis.
- dnoberon 7y ago
  Do you have an example use case you could share?
krapp 7y ago
I use it as a configuration and data language, mostly for building APIs for other libraries (like SDL2). The syntax is simple and clean, like JSON but without the most commonly cited warts (no requirement to quote keys, and comments are allowed.) The VM is lightweight enough that including it in an application is practically inconsequential. I like its modular syntax as well. There are also bindings for just about every language out there, making Lua code more easily portable and embeddable. It's not without its flaws as a language but to me, it's better suited as a config language than TOML, YAML or XML for most use cases where you don't actually need their complexity, or JSON if you're not on the web.
ammmir 7y ago
For KVdb [1], my managed key-value store database, I opted to integrate Lua as a scripting language instead of JavaScript because it felt super lightweight and the syntax is easy to learn in a few hours for even newbies. I'll probably end up adding JavaScript, too, since most developers know it, but there is a simplicity about Lua that I haven't seen in many other somewhat popular languages. [1] https://kvdb.io/docs/scripting https://kvdb.io/docs/scripting
jmiskovic 7y ago
I've built a collection of Android musical instruments [0] and Lua was big win for the project. I was previously familiar with Lua and Love2D framework and I wanted to see how far I can push it. The language is expressive and lightning fast. Very few building blocks that fit together nicely. I dig tables as first class objects, and meta-tables to turn them into complex objects or call delegation mechanism. My favorite feature is that it's interpreted. The Android app is just a runtime. I can edit source files right on the phone and re-execute. It's awesome prototyping platform. [0] https://github.com/jmiskovic/hexpress https://github.com/jmiskovic/hexpress
- exikyut 7y ago
  This is awesome, hilarious and fun. Thanks for posting it!
ur-whale 7y ago
BNF is amazingly short and therefore language is easy to learn [1] VM is tiny and can communicate bi-directionally with C / C++ code very easyly, makes it the ideal candidate for embedding in a larger app as a scripting language. [1]http://lua4z.com/doc/manual/syntax.md.html http://lua4z.com/doc/manual/syntax.md.html
0x14c1de72 7y ago
Pretty much only for modding software/games that provide a lua API. If I were to create a software like that I would definitely consider implementing a scripting interface with LUA.
TheCams 7y ago
I use it as a scripting language for my game engine, but also for all the tooling around it. Premake for generating the VS solution/makefiles, but also my own tools using IUPLua [1] and a few other modules (lfs, sqlite etc). Pretty much my whole ecosystem is C++/Lua. [1] - https://www.tecgraf.puc-rio.br/iup/en/iuplua.html https://www.tecgraf.puc-rio.br/iup/en/iuplua.html
williamaadams 7y ago
I use it as a way to rapidly prototype stuff related to new C-APIs https://github.com/wiladams https://github.com/wiladams Currently using it to create a tiny Postscript interpreter: https://github.com/wiladams/lj2ps https://github.com/wiladams/lj2ps
stevekemp 7y ago
I use it as the scripting, and implementation, language for a console-based mail-client. (Think "mutt", but with real scripting instead of the ad-hoc support that mutt has.) I use it because it's a simple language that is quick to code in, and trivial to embed inside a C, or C++, host application. If I were to begin the project again I'd have no qualms about a similar approach. (Writing the core in C++ with a notion of display-modes, email-parsing, etc, and the actual control in Lua. The biggest painpoints were dealing with MIME, and similar broken emails which was largely irrelevant for the lua-side.)
xorcist 7y ago
It's really big in the gaming industry. For certain engines it's the de facto standard.
- DonHopkins 7y ago
  Like Factorio! (If you haven't heard of that, then I implore you, for the love of God, don't look it up and try it out and get addicted, whatever you do! And if you do, then don't blame me for getting you hooked. Oh dammit, now I made myself want to play it again!)
dividuum 7y ago
It's the language used in my digital signage service for the Raspberry Pi (see https://info-beamer.com https://info-beamer.com & https://info-beamer.com/doc/info-beamer https://info-beamer.com/doc/info-beamer). The main reason to choose Lua back when I started was the there were no serious alternatives for: * Easy embedding. Compared to Python and ruby which I looked at back then, Lua is so much simpler. * Fairly easy to learn for users. After all, the complete syntax is one page long: https://www.lua.org/manual/5.1/manual.html#8 https://www.lua.org/manual/5.1/manual.html#8 * Quite expressive with coroutines, tail calls, metatables, ... * Trivially allows multiple interpreter instances within the same program. * More than fast enough, especially once LuaJIT was released.
- cuongt 7y ago
  That's really neat.
corysama 7y ago
I’ve used it in many games. It’s a simple, but powerful language that uses basically two features (functions and hashmaps) to implement everything. Ex: script files are implicitly functions. Global variables are in a hashmap. Semantically it is very much JavaScript without all the surprises. Semi-technical users (artists and designers) can figure it out and go on to make surprisingly powerful features. The binary code is small and fast. The standard library is small and most of it can be removed easily. Parsing source to bytecode is quick. Loading bytecode is very fast. It is easy to embed. It’s easy to contain it’s memory allocations in an arena. It’s easy to restrict what it can and cannot do. It’s easy to interface with C/C++. It’s extremely portable.
- OskarS 7y ago
  Your last line there is really one of the big keys. No other language is as easy to embed and interface with C/C++. The only real exceptions are some varieties of Lisp, but the "easily embeddable" ones tend not to be as mature, performant and robust as Lua. I'm no particular fan of the language, but they do the "embed and interface with C/C++" better than anything else I've seen.
doubleorseven 7y ago
I use it as a stateless HTTPS load balancer in NGINX where all the certs are stored on S3/GCS.
imtringued 7y ago
Mostly for running untrusted third party code (usually video game mods) inside a larger program that is written in C++.
andrewmcwatters 7y ago
Planimeter's Grid Engine is the largest pure-Lua game engine. https://www.planimeter.org/grid-sdk/ https://www.planimeter.org/grid-sdk/
mikey_p 7y ago
I used it because that's what I needed for configuring Hammerspoon. Been rather pleased with the language overall, but don't have any other uses for it. Hammerspoon has been killer, especially once I figured out some simple metaprogramming.
bjoli 7y ago
I embed it as a simple interactive query language for a time system at the local computer club. I wanted to use guile, but my fellow computer clubbers lose all their intelligence when they see parentheses.

My OpenStreetMap tag processing pipeline: OSRM, osm2pgsql and tilemaker all allow you to write tag-mangling scripts in Lua.

cobbzilla 7y ago

It’s great for embedded scripts in Redis.

dnoberon 7y ago
Do you have an example use case you could share?

krapp 7y ago

I use it as a configuration and data language, mostly for building APIs for other libraries (like SDL2). The syntax is simple and clean, like JSON but without the most commonly cited warts (no requirement to quote keys, and comments are allowed.) The VM is lightweight enough that including it in an application is practically inconsequential. I like its modular syntax as well. There are also bindings for just about every language out there, making Lua code more easily portable and embeddable. It's not without its flaws as a language but to me, it's better suited as a config language than TOML, YAML or XML for most use cases where you don't actually need their complexity, or JSON if you're not on the web.

ammmir 7y ago

For KVdb [1], my managed key-value store database, I opted to integrate Lua as a scripting language instead of JavaScript because it felt super lightweight and the syntax is easy to learn in a few hours for even newbies. I'll probably end up adding JavaScript, too, since most developers know it, but there is a simplicity about Lua that I haven't seen in many other somewhat popular languages. [1] https://kvdb.io/docs/scripting https://kvdb.io/docs/scripting

jmiskovic 7y ago

I've built a collection of Android musical instruments [0] and Lua was big win for the project. I was previously familiar with Lua and Love2D framework and I wanted to see how far I can push it. The language is expressive and lightning fast. Very few building blocks that fit together nicely. I dig tables as first class objects, and meta-tables to turn them into complex objects or call delegation mechanism. My favorite feature is that it's interpreted. The Android app is just a runtime. I can edit source files right on the phone and re-execute. It's awesome prototyping platform. [0] https://github.com/jmiskovic/hexpress https://github.com/jmiskovic/hexpress

exikyut 7y ago
This is awesome, hilarious and fun. Thanks for posting it!

ur-whale 7y ago

BNF is amazingly short and therefore language is easy to learn [1] VM is tiny and can communicate bi-directionally with C / C++ code very easyly, makes it the ideal candidate for embedding in a larger app as a scripting language. [1]http://lua4z.com/doc/manual/syntax.md.html http://lua4z.com/doc/manual/syntax.md.html

0x14c1de72 7y ago

Pretty much only for modding software/games that provide a lua API. If I were to create a software like that I would definitely consider implementing a scripting interface with LUA.

TheCams 7y ago

I use it as a scripting language for my game engine, but also for all the tooling around it. Premake for generating the VS solution/makefiles, but also my own tools using IUPLua [1] and a few other modules (lfs, sqlite etc). Pretty much my whole ecosystem is C++/Lua. [1] - https://www.tecgraf.puc-rio.br/iup/en/iuplua.html https://www.tecgraf.puc-rio.br/iup/en/iuplua.html

williamaadams 7y ago

I use it as a way to rapidly prototype stuff related to new C-APIs https://github.com/wiladams https://github.com/wiladams Currently using it to create a tiny Postscript interpreter: https://github.com/wiladams/lj2ps https://github.com/wiladams/lj2ps

stevekemp 7y ago

I use it as the scripting, and implementation, language for a console-based mail-client. (Think "mutt", but with real scripting instead of the ad-hoc support that mutt has.) I use it because it's a simple language that is quick to code in, and trivial to embed inside a C, or C++, host application. If I were to begin the project again I'd have no qualms about a similar approach. (Writing the core in C++ with a notion of display-modes, email-parsing, etc, and the actual control in Lua. The biggest painpoints were dealing with MIME, and similar broken emails which was largely irrelevant for the lua-side.)

xorcist 7y ago

It's really big in the gaming industry. For certain engines it's the de facto standard.

DonHopkins 7y ago
Like Factorio! (If you haven't heard of that, then I implore you, for the love of God, don't look it up and try it out and get addicted, whatever you do! And if you do, then don't blame me for getting you hooked. Oh dammit, now I made myself want to play it again!)

dividuum 7y ago

It's the language used in my digital signage service for the Raspberry Pi (see https://info-beamer.com https://info-beamer.com & https://info-beamer.com/doc/info-beamer https://info-beamer.com/doc/info-beamer). The main reason to choose Lua back when I started was the there were no serious alternatives for: * Easy embedding. Compared to Python and ruby which I looked at back then, Lua is so much simpler. * Fairly easy to learn for users. After all, the complete syntax is one page long: https://www.lua.org/manual/5.1/manual.html#8 https://www.lua.org/manual/5.1/manual.html#8 * Quite expressive with coroutines, tail calls, metatables, ... * Trivially allows multiple interpreter instances within the same program. * More than fast enough, especially once LuaJIT was released.

cuongt 7y ago
That's really neat.

corysama 7y ago

I’ve used it in many games. It’s a simple, but powerful language that uses basically two features (functions and hashmaps) to implement everything. Ex: script files are implicitly functions. Global variables are in a hashmap. Semantically it is very much JavaScript without all the surprises. Semi-technical users (artists and designers) can figure it out and go on to make surprisingly powerful features. The binary code is small and fast. The standard library is small and most of it can be removed easily. Parsing source to bytecode is quick. Loading bytecode is very fast. It is easy to embed. It’s easy to contain it’s memory allocations in an arena. It’s easy to restrict what it can and cannot do. It’s easy to interface with C/C++. It’s extremely portable.

OskarS 7y ago
Your last line there is really one of the big keys. No other language is as easy to embed and interface with C/C++. The only real exceptions are some varieties of Lisp, but the "easily embeddable" ones tend not to be as mature, performant and robust as Lua. I'm no particular fan of the language, but they do the "embed and interface with C/C++" better than anything else I've seen.

doubleorseven 7y ago

I use it as a stateless HTTPS load balancer in NGINX where all the certs are stored on S3/GCS.

imtringued 7y ago

Mostly for running untrusted third party code (usually video game mods) inside a larger program that is written in C++.

andrewmcwatters 7y ago

Planimeter's Grid Engine is the largest pure-Lua game engine. https://www.planimeter.org/grid-sdk/ https://www.planimeter.org/grid-sdk/

mikey_p 7y ago

I used it because that's what I needed for configuring Hammerspoon. Been rather pleased with the language overall, but don't have any other uses for it. Hammerspoon has been killer, especially once I figured out some simple metaprogramming.

bjoli 7y ago

I embed it as a simple interactive query language for a time system at the local computer club. I wanted to use guile, but my fellow computer clubbers lose all their intelligence when they see parentheses.