Hacker News Reader

Comment by andrewmcwatters | Hacker News Reader

No, it actually does originate from 1960's era programming practices. Not to say there weren't also 1-based or N-based numbering, but you're historically misled here.

You could also say the same about counting collections. No regular person counts 0... 1... 2... 3... and ends counting N-1. It, too, is a workaround.

View on HN

I don't think 0-based was ever as common a practice as it is today, especially in the 60s. In the beginning there were two camps fighting which system was to be preferred and there were many more 1-based or agnostic languages (like the whole Pascal family). "Numerical Recipes" a pretty popular book for some time even came in two editions, a 0-based and a 1-based version. I think the victory of C had a big influence on 0-based winning.

Personally I find it very sad that the agnostic approach of Pascal did not prevail. Let the programmer decide what they think fits the situation best and let the compiler deal with the technicalities. This, and I also miss range types... for like 40 years now...

Surely everything was 0-based initially, when everything was written in assembly? Are there any 1-based ISAs?

I wouldn't call assembly 0-based. Sure, the zero flag is convenient for branching on zero when counting backwards but what makes assembly 0-based apart from that? I'd say having a pointer to the first element of an array is pure convention and you could as easily point it to the imaginary element before, similar to how the program counter always points to the next imaginary instruction on most architectures.

The offset addressing modes all start from zero. You could hack around it in some places by storing the pointer to an element before but that's clearly going against how it is intended to be used.

For example if you have an array that you cast between different sized types (e.g. uint64 to uint8) then you have to change the pointer value!

> Personally I find it very sad that the agnostic approach of Pascal did not prevail. Let the programmer decide what they think fits the situation best and let the compiler deal with the technicalities. This, and I also miss range types... for like 40 years now...

I am with you there. However, Pascal, a toy Algol, was designed to be a language for a compiler course. It took its ideas like "where does an array start" from other Algol implementations and added a broken type system. Pascal gets the love now, as witnessed by the Lua designers referring to Pascal and not to Algol.

I don't think saurik is talking about history, so you're talking past each other in that sense.

I think so, too, but my point is that it makes sense for other historical reasons—not the one the poster mentions. Those decisions weren't made due to mathematics.

Agree. I came here to say that 0-based is more sensible, but as I thought through my arguments, I realised that I’m wrong. I do most of my coding in TS, Go and plpgsql. PL is 1 based, but the only time I find it frustrating is when translating between language boundaries. The rest of the time it’s just convention (eg, using <= instead of < in loops).

But I realised that I frequently want to get the last element in an array, and of course it’s easier with 1-based arrays.

So ultimately I don’t think it matters, except that most people are used to 0-based which can cause cognitive friction.

We aren't talking about counting. We are talking about indexing.

Most programs don't need numeric indexing. They can either treat indices as opaque keys or they can use a foreach loop to avoid touching indices at all (or friends like map, filter, zip, and so forth). Even in an old language like C the only place indices usually matter is in the first line of a for loop. But sometimes you really do need numeric indices, and when you do zero-based indices are almost always cleanest.

Just think of how gnarly a flat 2D array would be if you had to use one-based indices. Gross!

Reply on news.ycombinator.com