from fractions import Fraction from sys import maxint class PAdic: p = 2 def __init__(self): self.val = '' # current known value self.prec = 0 # current known precision self.order = 0 # order/valuation of number pass # initialize object as subclass perhaps def get(self, prec): 'Return value of number with given precision.' raise NotImplementedError # return value with precision up to 32 bits def __int__(self): return int(self.get(32), p) def __str__(self): return self.get(32) def __repr__(self): pass # arithmetic operations def __add__(self, other): return PAdicAdd(self, other) def __radd__(self, other): return PAdicAdd(other, self) def __sub__(self, other): return PAdicAdd(self, PAdicInv(other)) def __rsub__(self, other): return PAdicAdd(other, PAdicInv(self)) def __smul__(self, other): return PAdicMul(self, other) def __rsub__(self, other): return PAdicMul(other, self) # p-adic norm def __abs__(self): if self.order == maxint: return 0 norm = Fraction(1) if self.order > 0: norm.numerator = p ** self.order if self.order < 0: norm.denominator = p ** self.order return norm class PAdicConst(PAdic): def __init__(self, value): PAdic.__init__(self) value = Fraction(value) # calculate valuation if value == 0: self.value = value self.val = '0' return self.norm = Fraction(1) self.order = 0 while not value.numerator % p: self.norm /= p self.order += 1 value.numerator /= p while not value.denominator % p: self.norm *= p valuation -= 1 value.denominator /= p self.value = value def get(self, prec): 'Return value of constant with given precision.' if self.value == 0: return self.val while self.prec < prec: # update val based on value self.prec += 1 return self.val # TODO add decimal point or trailing zeros