Creating p-Adic polynomials from strings

[sagetrac-afiori]

It would be nice to be able to create polynomials over the p-adics by just copying the output from printing them.

sage: R = Qp(3,10)['x']
sage: P = R("1+3^-1+O(3^9)+(1+3+3^2)*x")
sage: P
(1 + 3 + 3^2 + O(3^10))*x + (3^-1 + 1 + O(3^9))

The attached patch lets this happen

CC: @roed314

Component: padics

Keywords: padicIMA

Author: Andrew Fiori

Issue created by migration from https://trac.sagemath.org/ticket/15421

[sagetrac-afiori]

Add a doctest

[sagetrac-vbraun-spam]

comment:1

Attachment: PadicPolyCasting.patch.gz

[roed314]

Changed keywords from none to padicIMA