As someone who's used Lua a lot as an embedded language in the VFX industry (The Games industry wasn't the only one that used it for that!), and had to deal with wrapping C++ and Python APIs with Lua (and vice-versa at times!), this is indeed very annoying, especially when tracing through callstacks to work out what's going on.
Eventually you end up in a place where it's beneficial to have converter functions that show up in the call stack frames so that you can keep track of whether the index is in the right "coordinate index system" (for lack of a better term) for the right language.
Oh that’s super interesting, where in the VFX industry is Lua common? I typically deal with Python and maybe Tcl (I do mostly Nuke and pipeline integrations), and I can’t think of a tool that is scripted in Lua. But I’ve never worked with Vega or Shake or what this is/was called
Katana uses LuaJIT quite extensively for user-side OpScripts, and previously both DNeg and MPC (they've largely moved on to newer tech now) had quite a lot of Lua code...
It used to in older (pre 2.0) versions, but due to Python's GIL lock (and the fact Python's quite a bit slower than lua anyway), it was pretty slow an inefficient using Python with AttributeScripts, so 2.0 moved to Lua with OpScripts...
It absolutely is. For a language whose biggest selling factor is embeddability with C/C++, that decision (and I'm being polite) is a headscratcher (along with the other similar source of errors: 0 evaluating to true).
It's the perfect distraction: once you start accepting one-based, everything else that might be not quite to your liking isn't worth talking about. I could easily imagine an alternative timeline where lua was zero-based, but never reached critical mass.
Absolutely so. It’s just one obvious thing from a large set of issues with it.
One can read through “mystdlib” part of any meaningful Lua-based project to see it. Things you’ll likely find there are: NIL, poor man’s classes, __newindex proxying wrapper, strict(), empty dict literal for json, “fixed” iteration protocols.
Perhaps that's the secret to lua's success: they got the basics so wrong that they can't fall into the trap of chasing the dream of becoming a better language, focusing on becoming a better implementation instead. Or perhaps even more important: not changing at all when it's obviously good enough for the niche it dominates.
That's an interesting notion but I think that Lua had no competition - it was almost unique in how easy it was to integrate vs the power it gives. Its popularity was inevitable that way.
I don't really blame Lua for that, though. 1-based indexing comes naturally to humans. It's the other languages which are backwards. I get why other languages are backwards from human intuition, I do. But if something has to be declared the bad guy, imo it's the paradigm which is at odds with human intuition which deserves that label, not the paradigm which fits us well.
To me 1 based indexing is natural if you stop pretending that arrays are pointers + index arithmetics. Especially with slicing syntax.
It's one of the things that irked me when switching to Julia from Python but which became just obviously better after I made the switch.
E.g. in Julia `1:3` represents the numbers 1 to 3. `A[1]` is the first element of the array, `A[1:3]` is a slice containing the first to third element. `A[1:3]` and `A[4:end]` partitions the array. (As an aside: `For i in 1:3` gives the number 1, 2, 3.)
The same sentence in python:
`1:3` doesn't make sense on its own. `A[0]` is the first element of the array. `A[0:3]` gives the elements `A[0], A[1]` and `A[2]`. `A[0:3]` and `A[3:]` slice the array.
For Python, which follows Dijkstra for its Slice delimiters, I need to draw a picture for beginners (I feel like the numpy documentation used to have this picture, but not anymore). The Julia option requires you to sometimes type an extra +1 but it's a meaningful +1 ("start at the next element") and even beginners never get this wrong.
That said, it seems to me that for Lua, with the focus on embedding in the C world, 0 index makes more sense.
I admire Dijkstra for many things, but this has always been a weak argument to me. To quote:
"when starting with subscript 1, the subscript range 1 ≤ i < N+1; starting with 0, however, gives the nicer range 0 ≤ i < N"
So it's "nicer", ok! Lua has a numeric for..loop, which doesn't require this kind of range syntax. Looping is x,y,step where x and y are inclusive in the range, i.e. Dijkstra's option (b). Dijkstra doesn't like this because iterating the empty set is awkward. But it's far more natural (if you aren't already used to languages from the 0-indexed lineage) to simply specify the lower and upper bounds of your search.
I actually work a lot with Lua, all the time, alongside other 0-indexed languages such as C and JS. I believe 0 makes sense in C, where arrays are pointers and the subscript is actually an offset. That still doesn't make the 1st item the 0th item.
Between this, and the fact that, regardless of language, I find myself having to add or subtract 1 frequently in different scenarios, I think it's less of a deal than people make it out to be.
In any language, arrays are inherently regions of memory and indexes are -- whether they start at 0 or 1 -- offsets into that region. When you implement more complicated algorithms in any language, whether or not it has pointers or how arrays are syntactically manipulated, you start having to do mathematical operations on both indexes and on ranges of index, and it feels really important to make these situations easier.
If you then even consider the simple case of nested arrays, I think it becomes really difficult to defend 1-based indexing as being cognitively easier to manipulate, as the unit of "index" doesn't naturally map to a counting number like that... if you use 0-based indexes, all of the math is simple, whereas with 1-based you have to rebalance your 1s depending on "how many" indexes your compound unit now represents.
And the reason to dismiss c) and d) is so that the difference between the delimiters is the length. That's not exactly profound either.
If the word for word same argument was made by an anonymous blogger no one would even consider citing this as a definitive argument that ends the discussion.
Associative arrays are also "nicer" with 1 based indexing
t={}
t[#t+1] --> t[1] DONE!
t[#t==0 and 0 or #t+1]
Now, in order to fix this (or achieve the same behavior as #t+1), the length operator must return -1, which would be ridiculous. its empty, and we have a perfect representation of emptiness in math "0".
This is also true in awk as well, nobody ever whines about awk "arrays" being 0
Especially when one of the language's main purposes is to be embedded in applications written in other languages (which are predominantly zero based) - and so you tend to have a lot of back-and-forth integration between these two styles that can get confusing. Even from the C API side, for example, the Lua stack is one-based but addressed exclusively from the host language which is likely zero-based.
