Re:Fintech engineering mistakes
by jerf on Wednesday June 28, 2023 @12:14PM
(#36508601)
"Can you confidently say that $100>¥10 in an offline environment?"
A major problem money has is that it isn't a unit in the sense we usually take the term to mean. We expect, for instance, that translating one unit to another with a suitable level of precision should be translatable without loss back to the original unit, but that's not true for money, even ignoring transaction costs. If "US dollar" is a unit, it is a unit that technically stands alone in its own universe, not truly convertible to anything else, not even other currencies. All conversions are transient events with no repeatability. But that is very inconvenient to deal with, and with sufficient value stability of all the relevant values, often it's a sufficient approximation to just pretend it's a unit. But if you zoom in enough, the approximation breaks down.
For that and similar reasons, while you could theoretically write that line of code, it would be implicitly depending on a huge pile of what would in most languages be global state. It would be a dubious line of code.
A major problem money has is that it isn't a unit in the sense we usually take the term to mean. We expect, for instance, that translating one unit to another with a suitable level of precision should be translatable without loss back to the original unit, but that's not true for money, even ignoring transaction costs. If "US dollar" is a unit, it is a unit that technically stands alone in its own universe, not truly convertible to anything else, not even other currencies. All conversions are transient events with no repeatability. But that is very inconvenient to deal with, and with sufficient value stability of all the relevant values, often it's a sufficient approximation to just pretend it's a unit. But if you zoom in enough, the approximation breaks down.
For that and similar reasons, while you could theoretically write that line of code, it would be implicitly depending on a huge pile of what would in most languages be global state. It would be a dubious line of code.