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Should be named initializeNameForOne:nameForMany:sign:

I'd like to add some information to the docs about modeling money. This has come up many times on the MLs of the various Smalltalk flavors, and Aconcagua has been mentioned many times. However, even after reading and re-reading, I'm still not clear how Aconcagua addresses the float problem. Namely, by way of example:

result := 0.
interval := 10.21.
10000 timesRepeat: [ result := result + interval ].
result = 102100.00000001806 "(not 102100.0)"

At first, I thought that using ScaledDecimal might help, but there were various comments saying that Pharo's ScaledDecimal is ill-conceived and maybe FixedDecimal would be better.

Another solution I thought of would be to convert any decimal money to dollars and cents and only convert back for display. For example:

Float>>dollars
	^ (AmDollar uniqueInstance * self // 1) +
(self \\ 1 * 100) asInteger cents.

Any feedback or input would be appreciated...

@gcotelli @mtaborda @hernanwilkinson

I tried the following and got aMeasureBag back, but I expected 10.21

amount := 10.21.
dollarAmt := amount // 1.
centsAmt := (amount \\ 1 * 100) asInteger.
total := (AmDollar new * dollarAmt) +
(centsAmt * AmCent new).
total / (1 * AmDollar new).

Also I tried convertTo: but got a subclassResponsibility error...

where:

AmDollar class>>#new
	^ super new
		initializeBaseUnit: AmCent new
		conversionFactor: 100
		nameForOne: 'dollar'
		nameForMany: 'dollars'
		sign: 'USD'

and

AmCent class>>#new
	^ super new
		initializeNameFomOne: 'cent'
		nameForMany: 'cents'
		sign: 'c USD'

It's been used in Chalten but not it Aconcagua. The implementation seems coupled with measures, maybe there is room for enhancement.

Evaluation and its subclasses doesn't have references

See discussion on #21

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