Sarcastically cute. It appears very parochial (in the sense of "limited or narrow outlook") to think that having a single "currency type" is useful, or that using a "$" to denote it is appropriate. While "$" is used by at least one important world currency, I am pretty sure that more people use ¥ than $ by a long shot, and users of € are about as plentiful as people who spend in USD.
(The idea that in Rebol one might write EUR$1.00 to denote the value that would usually be written 1.00€ is also pretty horrible)
1) Do you agree that a notation should support currency values? That is, they are useful to identify in data, as atomic units?
2) If so, do you agree there should be a single standard symbol and lexical form used to identify them? Because if we don't do that, we have to support every localized notation, correct?
3) If you agree to both of those questions, what symbol do you suggest? ¤ is generic, but not on any keyboard layout I know of. Also, see Chris's note about ASCII priority.
No, I can honestly say I've never worked on a software project that dealt directly with currency values. Personally, in the kinds of projects I do, explicit support for units of measurement would be more beneficial: you'd like to use the type system to detect where units from different systems are mixed (e.g., km+mi) and behave appropriately by performing a conversion; or to detect where inappropriate units are mixed (e.g., kg+hz) and signal an error (at project build time if possible!)
With that background in mind, I imagine the scenario here you have two data in a Ren document which are both the literal $1.00, but one is actually 1.00USD and the other is actually 1.00EUR: it doesn't prevent errors (for instance, when you want to perform an operation like + on the two data), because you still don't know what the data means. You have gained very little over just using the literal 1.00 instead.
So if I were making a proposal I'd be tempted to suggest a syntax like [1.00 USD], and maybe even giving up one of the remaining sigils ^[1.00 USD] if it is important to raise to being a special element in the syntax of a Ren file. Now that you're saying what you mean, you can use the same syntax for all units: ^[1.00 kg m -2] (1 kilogram per square meter), ^[1.00 V hz -.5] (1 volt per square-root-hertz, a typical units specification of noise in opamps).
No need for special syntax. ^ is already the escape character. Just use blocks. Though a `unit` syntax has been brought up. The notation would use path syntax, but start with an number instead of a word. Frink, of course, is the king of languages in this regard.
And while this may be more beneficial in your work, a lot of software does have to deal with money, where it's important not to use floating point, but BCD or something else.
Yes, I tried to be careful in what I stated, but here's what I meant: "$" is the everyday currency symbol of far fewer people than "¥". "USD" is the everyday currency of only about as many people as "EUR"
Of course "$" is used as the symbol for several currencies, but its not clear if you have a better symbol in mind for the generic concept of money.
https://en.wikipedia.org/wiki/$_(disambiguation)