[RFC] Sub-cent-precision | Bitcointalksearch.org

teknohog

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Quote from: grondilu on February 01, 2011, 08:55:03 AM

However, it's a bit unfortunate that the smallest amount is not exactly a nanobitcoin, but rather 10 nanobitcoins. It would have been simpler.

Chinese numerals are grouped in terms of 10^4, and the same system is used in Japan. I am not sure if this is the reason behind 10^-8 bitcoins, but at least it would appear simpler in those countries. 10^3 and 10^6 are only simpler for Westerners.

Then again, SI prefixes are by definition the international standard. If only they were actually used, instead of the billions and trillions whose meanings change by the country/continent.

Luke-Jr

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Solution to buggy JSON libraries (with base unit amounts): append a ".0" to all amounts, even though fractions are not possible. This should force all libraries with these bugs to treat it as a floating-point type, which is capable of representing the entire range. Embedded systems where floating-point is a problem can still validly ignore the ".0" and use int64.

Pieter Wuille

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Quote from: davout on February 01, 2011, 08:03:38 AM

There is no such thing as a fee-requiring-tx, the default miner won't mine for some transactions, but the warning message should not imply that it is the protocol that prevents very small free transactions but merely the default implementation of the miner.

Ok, agree. I think conventions for what and where fees are expected are a separate issue. But as long as no different set of rules is designed, and the client enforces those rules in the transactions it creates, no transactions that include a fee should be created beyond the user's (or JSON-RPC client's) control. Gavin's proposal does that nicely.

Quote from: Luke-Jr on February 01, 2011, 09:31:06 AM

Quote from: Pieter Wuille on February 01, 2011, 07:56:09 AM

although my personal opinion is that integer units are preferable, it may or may not be worth sacrificing backward compatibility for.

Integer units don't break backward compatibility at all, if implemented using a RPC versioning mechanism (eg, bitcoin.. prefix to methods, or--as MT suggested on IRC-- using a different URI path). This way, the old "RPC v0" can continue to function for as long as we care to maintain it, while new code can use RPC v1 with integer units.

Ok, agree as well. But again, maybe introducing a new version of the protocol may or may not be worth the effort.

Quote from: Luke-Jr on February 01, 2011, 09:31:06 AM

Given the fact that URIs are used, it might also be possible to simply use a query parameter (eg, "?precision=0", "?precision=1e8", "?precision=65536") to specify a division for all units explicitly (and default to "?precision=1e8" for backward compatibility for a while), while not forcing newer APIs to use base units.

That comes close to my "Idea 1", and brings us back to the issue of whether it is the responsibility of the JSON server to provide encoding/formatting of numeric amounts for human readability (and humans with varying tastes).

Luke-Jr

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I'm splitting the Tonal talk to another thread. It doesn't belong here.

Quote from: Pieter Wuille on February 01, 2011, 07:56:09 AM

although my personal opinion is that integer units are preferable, it may or may not be worth sacrificing backward compatibility for.

Integer units don't break backward compatibility at all, if implemented using a RPC versioning mechanism (eg, bitcoin.. prefix to methods, or--as MT suggested on IRC-- using a different URI path). This way, the old "RPC v0" can continue to function for as long as we care to maintain it, while new code can use RPC v1 with integer units. Given the fact that URIs are used, it might also be possible to simply use a query parameter (eg, "?precision=0", "?precision=1e8", "?precision=65536") to specify a division for all units explicitly (and default to "?precision=1e8" for backward compatibility for a while), while not forcing newer APIs to use base units.

grondilu

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Quote from: ribuck on February 01, 2011, 09:05:51 AM

The Nystrom representation itself isn't stupid, but using it for Bitcoin is. It brings absolutely nothing worthwhile to Bitcoin.

It brings more names to bitcoin subdivisions.

ribuck

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Quote from: grondilu on February 01, 2011, 08:55:03 AM

Well, this is Nystrom hexadecimal representation (http://en.wikipedia.org/wiki/John_W._Nystrom#Tonal_System_.28Hexadecimal.29), isn't it?

It doesn't seem stupid to me.

The Nystrom representation itself isn't stupid, but using it for Bitcoin is. It brings absolutely nothing worthwhile to Bitcoin.

One bitcoin is 100000000 units of bitdust, and the maximum number of bitcoins is 21000000, both of which are convenient decimal numbers. What's the point of having one Bong-Bitcoin equal to 42.94967296 BTC?

If you do want to count bitcoins in hexadecimal, you should simply use the equivalent number in base 16. For example, 255 BTC = 0xFF BTC.

grondilu

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Quote from: ribuck on February 01, 2011, 05:42:52 AM

Did you actually read the wiki page that you're describing as "cool"? This "Tonal Bitcoin" stuff is just stupid. "Bong-BitCoin" indeed!

Well, this is Nystrom hexadecimal representation (http://en.wikipedia.org/wiki/John_W._Nystrom#Tonal_System_.28Hexadecimal.29), isn't it?

It doesn't seem stupid to me. Anyway, it's just a complement to the standard 10^3-based prefix system.

However, it's a bit unfortunate that the smallest amount is not exactly a nanobitcoin, but rather 10 nanobitcoins. It would have been simpler.

davout

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1davout

Quote from: Pieter Wuille on February 01, 2011, 07:56:09 AM

Concerning sub-cent precision itself, i think gavin's suggestion is very good. The JSON-RPC interface should support all transactions and accounting at full precision, the client should actively avoid creating fee-requiring transactions, and creation of fee-requiring transactions shouldn't occur without the user's knowledge. I would suggest adding an optional maxtxfee argument (overriding the default) to the RPC calls which cause transactions to be sent though - i don't like a global setting shared by possibly more than one JSON-RPC client.

There is no such thing as a fee-requiring-tx, the default miner won't mine for some transactions, but the warning message should not imply that it is the protocol that prevents very small free transactions but merely the default implementation of the miner.

Pieter Wuille

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My original post - though split off from its original thread by gavin - was mainly about the internal representation used by JSON-RPC, and it seems that's also what most discussion here was about. This is a detail, and although my personal opinion is that integer units are preferable, it may or may not be worth sacrificing backward compatibility for.

Concerning sub-cent precision itself, i think gavin's suggestion is very good. The JSON-RPC interface should support all transactions and accounting at full precision, the client should actively avoid creating fee-requiring transactions, and creation of fee-requiring transactions shouldn't occur without the user's knowledge. I would suggest adding an optional maxtxfee argument (overriding the default) to the RPC calls which cause transactions to be sent though - i don't like a global setting shared by possibly more than one JSON-RPC client.

davout

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1davout

I'm not sure I get people's points right, my opinion, summed up is :
- GUI and JSON should allow every operation with full precision,
- It's the responsibility of the miners/clients to decide which transactions they want to include/relay
- No transaction fee should be auto-set, but not relaying free subcent transactions seems like a reasonable default

ribuck

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Quote from: grondilu on February 01, 2011, 02:30:10 AM

Quote from: Luke-Jr on January 31, 2011, 09:28:04 PM

Please see https://en.bitcoin.it/wiki/Units

Oh this seems cool. Sorry.

I should look at this wiki more often

Did you actually read the wiki page that you're describing as "cool"? This "Tonal Bitcoin" stuff is just stupid. "Bong-BitCoin" indeed!

grondilu

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Quote from: Luke-Jr on January 31, 2011, 09:28:04 PM

Please see https://en.bitcoin.it/wiki/Units

Oh this seems cool. Sorry.

I should look at this wiki more often

nanotube

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Quote from: grondilu on January 31, 2011, 05:34:43 PM

Quote from: nanotube on January 31, 2011, 05:28:50 PM

suggestion:
henceforth, 1e-8 bitcoins will be called "a bitcoin".
all bitcoin amounts will henceforth be integers.
sending 1 "oldbtc" to someone? just send 10million 'newbtc'.

solves all problems very neatly.
and also removes any psychological barriers around having "1 btc = 100usd"

EDIT: that said, i essentially like gavin's proposal, except for the cosmetics.

I strongly disagree.

An other, yet compatible possibility is to start from bottom :

1 coin = 10^-8 BTC
10^3 coins = 1 kilocoin = 10^-5 BTC
10^6 coins = 1 megacoin = 10^-2 BTC
10^9 coins = 1 gigacoin = 10 BTC

So one bitcoin would actually be 0.1 gigacoin, or 100 megacoins

so in other words... you agree. ok.

Luke-Jr

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Quote from: grondilu on January 31, 2011, 05:34:43 PM

We should keep the idea of using standard prefixes.

1 centibitcoin = 10^-2 BTC
1 millibitcoin = 10^-3 BTC
1 microbitcoin = 10^-6 BTC
1 nanobitcoin = 10^-9 BTC

In Satoshi's code, the smaller unit is called "the coin". We should use this.

1 coin = 10^-8 BTC = 10 nanobitcoins

Even if the nanobitcoin is too small a unit, we can still use it, as long as we only talk about multiples of 10. 10 nanobitcoins, 40 nanobitcoins, and so on...

An other, yet compatible possibility is to start from bottom :

1 coin = 10^-8 BTC
10^3 coins = 1 kilocoin = 10^-5 BTC
10^6 coins = 1 megacoin = 10^-2 BTC
10^9 coins = 1 gigacoin = 10 BTC

So one bitcoin would actually be 0.1 gigacoin, or 100 megacoins

Either way, the bitcoin should keep being "10^8 times the smaller unit"

Please, this is about program internals, nothing that should ever be visible to the end user.

Also, we already have plenty of decimal units, no need for more. A "COIN" (in the code), is defined as 0.01 BTC (1,000,000 base units aka centi-micro-bitcoin aka bitcoin-bong). "One bitcoin" is, regardless of anything discussed here, to remain at 10^8 base units for the short-term (long-term, it's too large to be viable). "An bitcoin" is also to remain at 16^4 for the foreseeable future. Please see https://en.bitcoin.it/wiki/Units

grondilu

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Quote from: nanotube on January 31, 2011, 05:28:50 PM

suggestion:
henceforth, 1e-8 bitcoins will be called "a bitcoin".
all bitcoin amounts will henceforth be integers.
sending 1 "oldbtc" to someone? just send 10million 'newbtc'.

solves all problems very neatly.
and also removes any psychological barriers around having "1 btc = 100usd"

EDIT: that said, i essentially like gavin's proposal, except for the cosmetics.

I strongly disagree.

We should keep the idea of using standard prefixes.

1 centibitcoin = 10^-2 BTC
1 millibitcoin = 10^-3 BTC
1 microbitcoin = 10^-6 BTC
1 nanobitcoin = 10^-9 BTC

In Satoshi's code, the smaller unit is called "the coin". We should use this.

1 coin = 10^-8 BTC = 10 nanobitcoins

Even if the nanobitcoin is too small a unit, we can still use it, as long as we only talk about multiples of 10. 10 nanobitcoins, 40 nanobitcoins, and so on...

An other, yet compatible possibility is to start from bottom :

1 coin = 10^-8 BTC
10^3 coins = 1 kilocoin = 10^-5 BTC
10^6 coins = 1 megacoin = 10^-2 BTC
10^9 coins = 1 gigacoin = 10 BTC

So one bitcoin would actually be 0.1 gigacoin, or 100 megacoins

Either way, the bitcoin should keep being "10^8 times the smaller unit"

nanotube

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suggestion:
henceforth, 1e-8 bitcoins will be called "a bitcoin".
all bitcoin amounts will henceforth be integers.
sending 1 "oldbtc" to someone? just send 10million 'newbtc'.

solves all problems very neatly.
and also removes any psychological barriers around having "1 btc = 100usd"

EDIT: that said, i essentially like gavin's proposal, except for the cosmetics.

grondilu

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Quote from: ribuck on January 31, 2011, 05:16:51 PM

Grondilu, taken in context it's clear that I'm referring to the psychological aspects of the internal representation, not the technical aspects.

Don't be offended. I just thought the sentence was itself extremly funny. I see your point, and it's perfectly valid, even if I think you're overestimating this psychological aspect a lot.

If I own one kilogram of gold, I don't feel richer if I tell myself that I own one thousand grams.

ribuck

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Quote from: grondilu on January 31, 2011, 04:57:14 PM

Quote from: ribuck on January 31, 2011, 04:45:47 PM

Some things in life are worth worrying about, but internal numeric representation is not one of them.

LOOOL

Grondilu, taken in context it's clear that I'm referring to the psychological aspects of the internal representation, not the technical aspects.

bitcool

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Live and enjoy experiments

Quote from: ribuck on January 31, 2011, 04:45:47 PM

Many financial libraries deal with whole cents instead of decimal dollars and cents, but there has been no long term psychological effect.
Some things in life are worth worrying about, but internal numeric representation is not one of them.

"The perfect is the enemy of the good", I guess I worried too much.

for a while, I thought I had a Bernanke moment.

grondilu

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Quote from: ribuck on January 31, 2011, 04:45:47 PM

Some things in life are worth worrying about, but internal numeric representation is not one of them.

LOOOL

Topic: [RFC] Sub-cent-precision (Read 6243 times)