This module contains internal functions (*Unsafe) that I had liked to re-use in the NumericPrelude type hierarchy. However since the Eq and Ord instance already require the Num class, we cannot use that in the NumericPrelude.
- data T a
- fromChunks :: C a => [a] -> T a
- fromNumber :: C a => a -> T a
- toChunks :: T a -> [a]
- toNumber :: C a => T a -> a
- zero :: T a
- normalize :: C a => T a -> T a
- isNull :: C a => T a -> Bool
- isPositive :: C a => T a -> Bool
- minMaxDiff :: C a => T a -> T a -> (T a, T a, Bool)
- fromChunksUnsafe :: [a] -> T a
- toChunksUnsafe :: T a -> [a]
A chunky non-negative number is a list of non-negative numbers. It represents the sum of the list elements. It is possible to represent a finite number with infinitely many chunks by using an infinite number of zeros.
Note the following problems:
Addition is commutative only for finite representations.
let y = min (1+y) 2 in y is defined,
let y = min (y+1) 2 in y is not.
minMaxDiff x y == (z,r,b)
min x y,
max x y - min x y,
xy == b or
x>y ==> not b,
x==y the value of b is arbitrary.
This routine exposes the inner structure of the lazy number
and is actually the same as
It was considered dangerous,
but you can observe the lazy structure
in tying-the-knot applications anyway.
So the explicit revelation of the chunks seems not to be worse.