Simplify NumberFieldElement._symbolic_

src/sage/rings/number_field/number_field_element.pyx

@@ -1727,7 +1727,7 @@ cdef class NumberFieldElement(FieldElement):
             sage: 2^a
             Traceback (most recent call last):
             ...
-            TypeError: An embedding into RR or CC must be specified.
+            TypeError: an embedding into RR or CC must be specified
         """
         if (isinstance(base, NumberFieldElement) and
             (isinstance(exp, Integer) or type(exp) is int or exp in ZZ)):
@@ -2149,7 +2149,7 @@ cdef class NumberFieldElement(FieldElement):
             sage: SR(a) # indirect doctest
             Traceback (most recent call last):
             ...
-            TypeError: An embedding into RR or CC must be specified.
+            TypeError: an embedding into RR or CC must be specified
 
         Now a more complicated example::
 
@@ -2194,50 +2194,25 @@ cdef class NumberFieldElement(FieldElement):
             sage: SR(a)
             (1/2*sqrt(5) + 1/2)^(1/3)
         """
-        if self.__symbolic is None:
-
-            K = self._parent.fraction_field()
-
-            gen = K.gen()
-            if not self is gen:
-                try:
-                    # share the hard work...
-                    gen_image = gen._symbolic_(SR)
-                    self.__symbolic = self.polynomial()(gen_image)
-                    return self.__symbolic
-                except TypeError:
-                    pass # we may still be able to do this particular element...
-
-            embedding = K.specified_complex_embedding()
-            if embedding is None:
-                raise TypeError, "An embedding into RR or CC must be specified."
-
-            if isinstance(K, number_field.NumberField_cyclotomic):
-                # solution by radicals may be difficult, but we have a closed form
-                from sage.all import exp, I, pi, ComplexField, RR
-                CC = ComplexField(53)
-                two_pi_i = 2 * pi * I
-                k = ( K._n()*CC(K.gen()).log() / CC(two_pi_i) ).real().round() # n ln z / (2 pi i)
-                gen_image = exp(k*two_pi_i/K._n())
-                if self is gen:
-                    self.__symbolic = gen_image
-                else:
-                    self.__symbolic = self.polynomial()(gen_image)
-            else:
-                from sage.rings.qqbar import AA, QQbar
-                from sage.rings.real_lazy import LazyField
-                if self.parent().is_totally_real():
-                    af = AA
-                else:
-                    af = QQbar
-                gen = embedding.gen_image()
-                if isinstance(gen.parent(), LazyField):
-                    gen = gen.eval(af)
-                else:
-                    gen = af(gen)
-                return SR(gen.radical_expression())
+        K = self._parent.fraction_field()
+
+        embedding = K.specified_complex_embedding()
+        if embedding is None:
+            raise TypeError("an embedding into RR or CC must be specified")
 
-        return self.__symbolic
+        if isinstance(K, number_field.NumberField_cyclotomic):
+            # solution by radicals may be difficult, but we have a closed form
+            from sage.all import exp, I, pi, ComplexField, RR
+            CC = ComplexField(53)
+            two_pi_i = 2 * pi * I
+            k = ( K._n()*CC(K.gen()).log() / CC(two_pi_i) ).real().round() # n ln z / (2 pi i)
+            gen_image = exp(k*two_pi_i/K._n())
+            return self.polynomial()(gen_image)
+        else:
+            from sage.rings.qqbar import QQbar
+            gen = embedding.gen_image()
+            element = self.polynomial()(gen.eval(QQbar))
+            return SR(element.radical_expression())
 
     def galois_conjugates(self, K):
         r"""