Ticket #4376: trac_4376.patch

sage/modular/overconvergent/genus0.py

@@ -1637 +1637 @@
     def _pari_(self):
         r"""
         Return the Pari object corresponding to self, which is just the
-        `q`-expansion of self as a formal power series. At present conversion of
-        power series to Pari is only implemented if the base ring is
-        `\QQ`.
+        `q`-expansion of self as a formal power series. 
 
-        (At present, in 3.4.1.alpha0, if the base ring isn't QQ then a silly
-        error message comes up because of a trivial typo in
-        sage/rings/power_series_ring_element.py -- isinstance is being given a
-        constructor function, not a class, due to code refactoring. The really
-        silly thing is that there was no doctest to catch this when IntegerRing
-        became a function rather than a class. It's really somewhat astonishing
-        nobody has noticed since.)
-        
         EXAMPLES::
 
             sage: f = OverconvergentModularForms(3, 0, 1/2).1
             sage: pari(f) # indirect doctest
             27*q + 324*q^2 + 2430*q^3 + 13716*q^4 + 64557*q^5 + 265356*q^6 + 983556*q^7 + 3353076*q^8 + 10670373*q^9 + 32031288*q^10 + 91455804*q^11 + 249948828*q^12 + 657261999*q^13 + 1669898592*q^14 + 4113612864*q^15 + 9853898292*q^16 + 23010586596*q^17 + 52494114852*q^18 + 117209543940*q^19 + O(q^20)
-            sage: pari(f.base_extend(Qp(3))) # misleading error message!
-            Traceback (most recent call last):
-            ...
-            TypeError: isinstance() arg 2 must be a class, type, or tuple of classes and types
+            sage: pari(f.base_extend(Qp(3))) # indirect doctest
+            (3^3 + O(3^23))*q + (3^4 + 3^5 + O(3^24))*q^2 + (3^5 + 3^7 + O(3^25))*q^3 + (3^3 + 3^4 + 2*3^5 + 2*3^8 + O(3^23))*q^4 + (2*3^4 + 3^5 + 3^6 + 2*3^7 + 3^10 + O(3^24))*q^5 + (3^6 + 3^7 + 3^8 + 3^9 + 3^10 + 3^11 + O(3^26))*q^6 + (2*3^3 + 3^4 + 2*3^6 + 2*3^7 + 2*3^8 + 3^9 + 3^10 + 2*3^11 + 3^12 + O(3^23))*q^7 + (2*3^4 + 3^5 + 3^8 + 2*3^9 + 2*3^10 + 2*3^13 + O(3^24))*q^8 + (3^7 + 2*3^9 + 2*3^12 + 2*3^14 + O(3^27))*q^9 + (2*3^5 + 3^8 + 3^9 + 2*3^10 + 2*3^13 + 2*3^15 + O(3^25))*q^10 + (3^4 + 2*3^5 + 2*3^6 + 3^8 + 2*3^9 + 3^12 + 3^14 + 2*3^16 + O(3^24))*q^11 + (3^5 + 3^6 + 2*3^8 + 2*3^9 + 2*3^10 + 2*3^12 + 3^14 + 2*3^15 + 2*3^16 + 3^17 + O(3^25))*q^12 + (2*3^3 + 2*3^4 + 2*3^5 + 3^8 + 2*3^9 + 2*3^11 + 3^13 + 2*3^14 + 2*3^17 + 3^18 + O(3^23))*q^13 + (2*3^4 + 2*3^6 + 2*3^7 + 3^8 + 2*3^9 + 3^10 + 3^12 + 3^14 + 2*3^15 + 2*3^16 + 3^18 + 3^19 + O(3^24))*q^14 + (2*3^6 + 3^7 + 3^9 + 3^10 + 3^11 + 2*3^14 + 3^15 + 2*3^16 + 3^17 + 3^18 + 3^20 + O(3^26))*q^15 + (3^3 + 2*3^4 + 2*3^7 + 2*3^8 + 3^9 + 3^10 + 2*3^11 + 3^12 + 2*3^14 + 2*3^15 + 3^17 + 3^18 + 2*3^19 + 2*3^20 + O(3^23))*q^16 + (2*3^5 + 2*3^7 + 2*3^8 + 3^10 + 3^11 + 2*3^12 + 2*3^13 + 3^14 + 3^15 + 3^17 + 2*3^18 + 3^19 + 2*3^21 + O(3^25))*q^17 + (3^8 + 3^9 + 2*3^10 + 2*3^11 + 3^12 + 3^14 + 3^15 + 3^16 + 3^17 + 2*3^21 + 3^22 + O(3^28))*q^18 + (2*3^3 + 3^5 + 2*3^6 + 2*3^8 + 2*3^9 + 3^11 + 2*3^12 + 3^13 + 3^14 + 2*3^15 + 3^16 + 3^17 + 2*3^18 + 3^19 + 2*3^21 + O(3^23))*q^19 + O(q^20)
         """
         return self.q_expansion()._pari_()

sage/rings/power_series_ring_element.pyx

@@ -1720 +1720 @@
         """
         Return PARI power series corresponding to this series.
         
-        This is currently only implemented over QQ and ZZ.
-        
+        There are currently limits to the possible base rings over which this
+        function works.  See the documentation for
+        ``sage.rings.polynomial.polynomial_element.Polynomial._pari_``
+
         EXAMPLES::
         
             sage: k.<w> = QQ[[]]
             sage: f = 1+17*w+15*w^3+O(w^5)
-            sage: pari(f)
+            sage: pari(f) # indirect doctest
             1 + 17*w + 15*w^3 + O(w^5)
-            sage: pari(1 - 19*w + w^5)
+            sage: pari(1 - 19*w + w^5) # indirect doctest
             Traceback (most recent call last):
             ...
-            RuntimeError: series precision must be finite for conversion to pari object.
+            ValueError: series precision must be finite for conversion to pari object.
+            sage: R.<x> = Zmod(6)[[]]
+            sage: pari(1 + x + 8*x^3 + O(x^8)) # indirect doctest
+            Mod(1, 6) + Mod(1, 6)*x + Mod(2, 6)*x^3 + O(x^8)
         """
-        if not isinstance(self.parent().base_ring(),
-                          (rational_field.RationalField, integer_ring.IntegerRing)):
-            raise NotImplementedError
-        if self.prec() is infinity:
-            raise RuntimeError, "series precision must be finite for conversion to pari object."
-        return sage.libs.pari.all.pari(str(self))
-
-            
-
+        n = self.prec()
+        if n is infinity:
+            raise ValueError, "series precision must be finite for conversion to pari object."
+        s = '+'.join([str(self.truncate()._pari_()), 'O(%s^%s)' % (self.variable(), n)])
+        return sage.libs.pari.all.pari(s)
 
 def _solve_linear_de(R, N, L, a, b, f0):
     r"""