Add Rationals

Author: rikardn

symengine/__init__.py

@@ -29,6 +29,7 @@
 UniversalSet = wrapper.S.UniversalSet
 Reals = wrapper.S.Reals
 Integers = wrapper.S.Integers
+Rationals = wrapper.S.Rationals
 
 
 if have_mpfr:

symengine/lib/symengine.pxd

@@ -302,6 +302,7 @@ cdef extern from "<symengine/basic.h>" namespace "SymEngine":
     bool is_a_Interval "SymEngine::is_a<SymEngine::Interval>"(const Basic &b) nogil
     bool is_a_EmptySet "SymEngine::is_a<SymEngine::EmptySet>"(const Basic &b) nogil
     bool is_a_Reals "SymEngine::is_a<SymEngine::Reals>"(const Basic &b) nogil
+    bool is_a_Rationals "SymEngine::is_a<SymEngine::Rationals>"(const Basic &b) nogil
     bool is_a_Integers "SymEngine::is_a<SymEngine::Integers>"(const Basic &b) nogil
     bool is_a_UniversalSet "SymEngine::is_a<SymEngine::UniversalSet>"(const Basic &b) nogil
     bool is_a_FiniteSet "SymEngine::is_a<SymEngine::FiniteSet>"(const Basic &b) nogil
@@ -1056,6 +1057,8 @@ cdef extern from "<symengine/sets.h>" namespace "SymEngine":
         pass
     cdef cppclass Reals(Set):
         pass
+    cdef cppclass Rationals(Set):
+        pass
     cdef cppclass Integers(Set):
         pass
     cdef cppclass UniversalSet(Set):
@@ -1074,6 +1077,7 @@ cdef extern from "<symengine/sets.h>" namespace "SymEngine":
     cdef rcp_const_basic interval(RCP[const Number] &start, RCP[const Number] &end, bool l, bool r) nogil except +
     cdef RCP[const EmptySet] emptyset() nogil except +
     cdef RCP[const Reals] reals() nogil except +
+    cdef RCP[const Rationals] rationals() nogil except +
     cdef RCP[const Integers] integers() nogil except +
     cdef RCP[const UniversalSet] universalset() nogil except +
     cdef RCP[const Set] finiteset(set_basic &container) nogil except +

symengine/lib/symengine_wrapper.pyx

@@ -239,6 +239,8 @@ cdef object c2py(rcp_const_basic o):
         r = Set.__new__(Reals)
     elif (symengine.is_a_Integers(deref(o))):
         r = Set.__new__(Integers)
+    elif (symengine.is_a_Rationals(deref(o))):
+        r = Set.__new__(Rationals)
     elif (symengine.is_a_UniversalSet(deref(o))):
         r = Set.__new__(UniversalSet)
     elif (symengine.is_a_FiniteSet(deref(o))):
@@ -451,6 +453,8 @@ def sympy2symengine(a, raise_error=False):
         return S.Reals
     elif a is sympy.S.Integers:
         return S.Integers
+    elif a is sympy.S.Rationals:
+        return S.Rationals
     elif isinstance(a, sympy.Interval):
         return interval(*(a.args))
     elif a is sympy.S.EmptySet:
@@ -669,6 +673,10 @@ class Singleton(object):
     def Integers(self):
         return integers_singleton
 
+    @property
+    def Rationals(self):
+        return rationals_singleton
+
     @property
     def Reals(self):
         return reals_singleton
@@ -3020,6 +3028,20 @@ class Reals(Set):
         return self.__class__
 
 
+class Rationals(Set):
+
+    def __new__(self):
+        return rationals()
+
+    def _sympy_(self):
+        import sympy
+        return sympy.S.Rationals
+
+    @property
+    def func(self):
+        return self.__class__
+
+
 class Integers(Set):
 
     def __new__(self):
@@ -5185,6 +5207,10 @@ def reals():
     return c2py(<rcp_const_basic>(symengine.reals()))
 
 
+def rationals():
+    return c2py(<rcp_const_basic>(symengine.rationals()))
+
+
 def integers():
     return c2py(<rcp_const_basic>(symengine.integers()))
 
@@ -5299,6 +5325,7 @@ def imageset(sym, expr, base):
 
 universal_set_singleton = UniversalSet()
 integers_singleton = Integers()
+rationals_singleton = Rationals()
 reals_singleton = Reals()
 empty_set_singleton = EmptySet()
 

symengine/tests/test_sets.py

@@ -1,7 +1,7 @@
 from symengine.utilities import raises
 from symengine.lib.symengine_wrapper import (Interval, EmptySet, UniversalSet,
-    FiniteSet, Union, Complement, ImageSet, ConditionSet, Reals, Integers,
-    And, Or, oo, Symbol, true, Ge, Eq, Gt)
+    FiniteSet, Union, Complement, ImageSet, ConditionSet, Reals, Rationals,
+    Integers, And, Or, oo, Symbol, true, Ge, Eq, Gt)
 
 
 def test_Interval():
@@ -38,7 +38,13 @@ def test_Reals():
     assert R.contains(0) == true
 
 
-def test_Reals():
+def test_Rationals():
+    Q = Rationals()
+    assert Q.union(FiniteSet(2, 3)) == Q
+    assert Q.contains(0) == true
+
+
+def test_Integers():
     Z = Integers()
     assert Z.union(FiniteSet(2, 4)) == Z
     assert Z.contains(0) == true

symengine/tests/test_sympy_conv.py

@@ -9,7 +9,7 @@
         KroneckerDelta, LeviCivita, erf, erfc, lowergamma, uppergamma,
         loggamma, beta, polygamma, sign, floor, ceiling, conjugate, And,
         Or, Not, Xor, Piecewise, Interval, EmptySet, FiniteSet, Contains,
-        Union, Complement, UniversalSet, Reals, Integers)
+        Union, Complement, UniversalSet, Reals, Rationals, Integers)
 import unittest
 
 # Note: We test _sympy_() for SymEngine -> SymPy conversion, as those are
@@ -721,6 +721,9 @@ def test_sets():
     assert sympify(sympy.S.Reals) == Reals()
     assert sympy.S.Reals == Reals()._sympy_()
 
+    assert sympify(sympy.S.Rationals) == Rationals()
+    assert sympy.S.Rationals == Rationals()._sympy_()
+
     assert sympify(sympy.S.Integers) == Integers()
     assert sympy.S.Integers == Integers()._sympy_()