padicprec

Function: padicprec
Section: conversions
C-Name: gppadicprec
Prototype: GG
Help: padicprec(x,p):
 return the absolute p-adic precision of object x.
Doc: returns the absolute $p$-adic precision of the object $x$; this is the
 minimum precision of the components of $x$. The result is \tet{+oo} if $x$
 is an exact object (as a $p$-adic):
 \bprog
 ? padicprec((1 + O(2^5)) * x + (2 + O(2^4)), 2)
 %1 = 4
 ? padicprec(x + 2, 2)
 %2 = +oo
 ? padicprec(2 + x + O(x^2), 2)
 %3 = +oo
 @eprog\noindent The function raises an exception if it encounters
 an object incompatible with $p$-adic computations:
 \bprog
 ? padicprec(O(3), 2)
  ***   at top-level: padicprec(O(3),2)
  ***                 ^-----------------
  *** padicprec: inconsistent moduli in padicprec: 3 != 2

 ? padicprec(1.0, 2)
  ***   at top-level: padicprec(1.0,2)
  ***                 ^----------------
  *** padicprec: incorrect type in padicprec (t_REAL).
 @eprog

Variant: Also available is the function \fun{long}{padicprec}{GEN x, GEN p},
 which returns \tet{LONG_MAX} if $x = 0$ and the $p$-adic precision as a
 \kbd{long} integer.