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Comment by jensenbox | Hacker News Reader

Personally, I like this a lot. What are the potential downsides?

There have been some pretty heavy critiques of it when it has been posted to HN in the past, e.g. https://news.ycombinator.com/item?id=7367021

It looks like the biggest critique is that checking for equality is slow, but checking floats for equality is almost always a bug anyway.

The base is 10, but the mantissa is in binary. Before you add or subtract you must get the numbers to have equal exponents. In other formats you can do it with shifting, but this format requires binary multiplication or division.

S9fES (http://t3x.org/s9fes/) uses decimal-based real numbers and does multiplication, division and exponent equalization by shifting. It's not hard, since one digit equals one byte.

I think that the chance of this becoming prevalent is low. While it has its merit as a representation, floating point is already "good enough" for most computations. More importantly, it is ubiquitous.

Additionally, I don't know if there are enough compelling problems that require decimal numbers, can't take the hit of software emulation, and are willing to bind their performance to hardware that would take a while to be adopted, if at all.

I could be wrong though.

Floating point is really stupid for most computations. Can't store floating point numbers when dealing with money (have to store the number of cents or something equally stupid so you don't tell Paypal to sell something for $12.999999999999996 because they won't accept that price)

Can't store floating point numbers when you really need a ratio because it won't even work after you round it unless you reconcile different settings for precision. Decimal won't help here either.

So outside of niche scientific uses or something like graphics where you need performance, what do you really need floating point numbers for? I haven't had a need for floating point numbers outside of some mathematical formulae.

> So outside of niche scientific uses or something like graphics where you need performance, what do you really need floating point numbers for? I haven't had a need for floating point numbers outside of some mathematical formulae.

This is... a weird thing to say. Obviously floats are going to be most useful for math, and not useful for much else. They're number types.

Yes, but decimal numbers would be useful in:

1. Game score display where fractional points are possible

2. Currency

3. Any amount displayed to humans (like pounds of beef sold)

because decimal number correspond to what you're going to display to the user, while binary numbers are only useful for the result they produce inside an algorithm

So what is your point?

> what do you really need floating point numbers for?

For representing real (i.e., potentially irrational or transcendental) numbers. Irrational and transcendental numbers are actually very common in nature.

But you're right that representing rational numbers with floating point is stupid.

Instead of inventing new one-size-fits-all coding schemes, people should focus instead on making the idea of a rational number type mainstream.

This wouldn't even be an issue worth discussing if popular programming languages and DBMS's supported rational numbers.

I like it, too. The word size is so large it's not a goo. Dimple dance match for embedded processing.

Let's try that again: "not a good impedance match"

It'll never replace the VAX.

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