Module Tally

Arithmetic support for "zero-agnostic" numbers.

Example use:

# simple addition test
a = Tally(["19"])
b = Tally(["1"])
c = a + b
print c.possibilities() # set([110,20])

# simple multiplication test
a = Tally(10)
c = a * 3
print c.possibilities() # set([120, 210, 30, 1110])

Classes

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TallyNum
A single "zero agnostic" number, as represented in khipu.

Tally
A set of "zero-agnostic" numbers which could represent the sum of several cords in a khipu.

Functions

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_addFast(a, b, limit=None, cache=None)
Add two zero-agnostic values, specially treating the least-significant digit (whose position is fixed).

source code

_addSlow(a, b, limit=None, cache=None)
Add two TallyNum objects, specially treating the least-significant digit (whose position is fixed).

source code

main()

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profile()

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psyco()

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Function Details

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_addFast(a, b, limit=None, cache=None)

source code

Add two zero-agnostic values, specially treating the least-significant digit (whose position is fixed). This is 'fast' addition: carries are reduced immediately, which means addition is not commutative as the results may (conservatively) include extra values. For example, 18+(51+52) will (incorrectly) include '31' as a possibility, since 51+52=103=13.

_addSlow(a, b, limit=None, cache=None)

source code

Add two TallyNum objects, specially treating the least-significant digit (whose position is fixed). This is 'slow' addition: carries are preserved and digits are not reduced, which guarantees commutativity but requires special care during comparison.