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Comment by alayne | Hacker News Reader

Not only does Lua have the length problem, but array offsets are a matter of convention. Lua chooses 1 as the first element of an array instead of 0. But that is just convention. Your code could use 0 or -100. A confusing implementation of length and offsets by convention instead of using nearly universal array semantics from other languages is not "well-designed". It's a cheap hack to conflate everything into one table data structure.

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> array offsets are a matter of convention. Lua chooses 1 as the first element of an array instead of 0. But that is just convention. Your code could use 0 or -100.

Not sure what your point is here. Lua arrays start at 1. If you disobey this rule, your table isn't really an array and the length operator will be undefined starting in Lua 5.2.

Sure you could disobey this rule and create an array that starts at -100. You can do the same in C:

    // Array whose indices start at -100:
    char *funky_array = (char*)malloc(n * sizeof(char)) + 100;

> It's a cheap hack to conflate everything into one table data structure.

You say "cheap hack" I say "brilliant optimization." Show me an equally-capable language that has a <100kb interpreter and performs as well as Lua. Lua fulfills its design goals brilliantly.

Perl 5 has $[ which lets you set the base for every array. eg. $[ = 1; would cause all arrays to be 1-based. Thankfully they've now deprecated this misfeature ...

http://perldoc.perl.org/perlvar.html#Deprecated-and-removed-...

I thought that was deprecated a long time ago. When I learned Perl in 2000 I remember I read not to use that "feature". Apparently it was just not recommended, for a very long time.

Certainly the advice has been don't use it for a very long time. At least since the 90s when I learned Perl. However it wasn't actually deprecated until last year (Perl 5.12). There were a sequence of steps leading up to full deprecation which you can read about in the link I provided above. Maybe some people were actually using it?!?

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