Lua Doesn't Suck – Strange Loop 2010 20-minute talk video

Besides, Lua strings are interned raw byte-arrays (like atoms in Erlang or Lisp atoms), and can have \0s and other arbitrary binary data. While the standard string library is ignorant of Unicode, there's nothing preventing extra libraries from providing Unicode-aware string operations.

Lua also left out native regular expression support, because it would be larger than the rest of the standard libraries put together. You can just load LPEG if it matters.

I haven't had a need for Unicode in Lua, but when I stumbled across some information about it, the essential story was that there is nothing stopping you from writing code to manipulate Unicode data (obviously), but there is also nothing built in to help you. All the built in string stuff is ANSI/ASCII/whatever.

However, the language Io (which often gets mentioned in the same breath as Lua, though it's quite different in some ways) has a stronger Unicode story: http://www.iolanguage.com/scm/io/docs/IoGuide.html#Unicode

Also, Unicode is an odd thing to consider to be an essential part of a programming language. Usually when I hear it I think the person must think it's a part of accepting those that speak other languages. I would point out the fact that Ruby took much longer to get Unicode support than Python as a counterpoint to that, as Ruby's creator, Matz, is Japanese.

ICU4Lua hasn't been touched since April 2009, and is at 0.2B. [http://luaforge.net/projects/icu-lua/]

That sort of status just doesn't inspire confidence in a language. I understand you can use it for game programming, or that you can write your own libraries for it, but that sort of thing doesn't encourage adoption.

If you're putting Lua in a commercial application, the commercial application itself will provide the i18n, and Lua can use it with very little trouble. Lua's strings are raw byte arrays - you can load arbitrary binary data in them. A library that reads UTF-8 strings (say) can work with them just fine. (And while I don't speak Portuguese, there are examples in PiL that use it without problems.)

I disagree with you about whether metatables are annoying, but it's a matter of taste. I haven't ever used NewtonScript, but I do use metatables for quite a bit more than just prototype OO - it's easy to turn a table into a proxy + cache to a function, for example. Also, my Lua redis library (http://github.com/silentbicycle/sidereal) turns table reads and writes into syntactic sugar for redis db key, list, and set operations.

           Rate python swipl ruby perl  lua luac bash ocaml  awk subshell ocamlopt    c py_pyc shell
    python   46.3/s     --  -17% -56% -70% -76% -78% -78%  -79% -83%     -87%     -88% -88%   -90%  -92%
    swipl    55.9/s    21%    -- -46% -63% -70% -73% -73%  -74% -80%     -84%     -85% -86%   -88%  -90%
    ruby      104/s   125%   86%   -- -31% -45% -49% -51%  -52% -62%     -71%     -72% -74%   -79%  -82%
    perl      152/s   229%  172%  46%   -- -20% -26% -28%  -30% -44%     -57%     -60% -61%   -69%  -74%
    lua       189/s   309%  239%  82%  25%   --  -8% -10%  -13% -31%     -47%     -50% -52%   -61%  -67%
    luac      206/s   345%  268%  98%  35%   9%   --  -2%   -6% -25%     -42%     -46% -48%   -58%  -64%
    bash      211/s   356%  277% 103%  39%  11%   3%   --   -3% -23%     -41%     -44% -46%   -57%  -63%
    ocaml     218/s   372%  290% 110%  44%  15%   6%   3%    -- -20%     -39%     -42% -45%   -55%  -62%
    awk       273/s   491%  389% 162%  80%  44%  33%  30%   25%   --     -23%     -28% -31%   -44%  -52%
    subshell  357/s   672%  539% 243% 135%  89%  74%  69%   64%  31%       --      -6%  -9%   -26%  -38%
    ocamlopt  379/s   719%  577% 264% 149% 100%  84%  80%   73%  39%       6%       --  -4%   -22%  -34%
    c         394/s   751%  604% 278% 159% 108%  91%  87%   80%  44%      10%       4%   --   -19%  -31%
    py_pyc    485/s   950%  768% 366% 219% 156% 136% 130%  122%  78%      36%      28%  23%     --  -16%
    shell     575/s  1143%  928% 452% 278% 203% 179% 172%  163% 110%      61%      52%  46%    18%    --

Edit: Since you can precompile Lua, I added that as 'luac'. It's not usually done, since Lua compiles VERY quickly, and the source is more portable. It's a data point, though. I also added a .pyc for Python - Python byte-compiles more slowly. There's little difference between lua and luac, but the difference between python and py_pyc is huge.

I also added shell with a new subshell, both sh and bash. And, source, as requested.

OCaml:

    let _ = print_string "Hello world.\n"

SWI Prolog:

    swipl => sub { system qq[swipl -g "write('Hello world.\n')." -t "halt."] },

    print "Hello, world."

In my experience 1-based indexing is not a problem when you're just writing Lua code. I've sometimes been frustrated when creating Lua bindings to C-modules which involved some kind of array access though.

It just bugs me that such an obvious wart exists in an otherwise very clean language.