docs: update Amount haddock

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Simon Michael 2009-12-12 21:10:39 +00:00
parent d3083ef316
commit 5018fd459d

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@ -10,30 +10,27 @@ A simple amount is a 'Commodity', quantity pair:
EUR 3.44
GOOG 500
1.5h
90apples
90 apples
0
@
A 'MixedAmount' is zero or more simple amounts:
@
$50 + EUR 3
16h + $13.55 + AAPL 500 + 6 oranges
@
Amounts often have a price per unit, or conversion rate, in terms of
another commodity. If present, this is displayed after \@:
An amount may also have a per-unit price, or conversion rate, in terms
of some other commodity. If present, this is displayed after \@:
@
EUR 3 \@ $1.35
@
A normalised mixed amount has at most one amount in each commodity-price,
and no zero amounts (or it has just a single zero amount and no others.)
A 'MixedAmount' is zero or more simple amounts. Mixed amounts are
usually normalised so that there is no more than one amount in each
commodity, and no zero amounts (or, there is just a single zero amount
and no others.):
In principle we can convert an amount to any other commodity to which we
have a known sequence of conversion rates; in practice we only do one
conversion step (eg to show cost basis with -B).
@
$50 + EUR 3
16h + $13.55 + AAPL 500 + 6 oranges
0
@
We can do limited arithmetic with simple or mixed amounts: either
price-preserving arithmetic with similarly-priced amounts, or