Merge pull request #178 from ShikharJ/Singleton

Implemented Singleton Pattern

Author: isuruf

symengine/__init__.py

@@ -1,4 +1,4 @@
-from .lib.symengine_wrapper import (Symbol, sympify as S, sympify,
+from .lib.symengine_wrapper import (Symbol, S, sympify,
         SympifyError, Add, Mul, Pow, function_symbol, I, E, pi, oo,
         zoo, nan, have_mpfr, have_mpc, have_flint, have_piranha,
         have_llvm, Integer, Rational, Float, Number, RealNumber,
@@ -9,8 +9,9 @@
         UndefFunction, Function, FunctionSymbol as AppliedUndef,
         have_numpy, true, false, Equality, Unequality, GreaterThan,
         LessThan, StrictGreaterThan, StrictLessThan, Eq, Ne, Ge, Le,
-        Gt, Lt, GoldenRatio, Catalan, EulerGamma, Dummy, perfect_power,
-        integer_nthroot, isprime, sqrt_mod)
+        Gt, Lt, golden_ratio as GoldenRatio, catalan as Catalan,
+        eulergamma as EulerGamma, Dummy, perfect_power, integer_nthroot,
+        isprime, sqrt_mod)
 from .utilities import var, symbols
 from .functions import *
 

symengine/lib/symengine.pxd

@@ -332,6 +332,8 @@ cdef extern from "<symengine/number.h>" namespace "SymEngine":
         bool is_positive() nogil
         bool is_negative() nogil
         bool is_zero() nogil
+        bool is_one() nogil
+        bool is_minus_one() nogil
         bool is_complex() nogil
         pass
     cdef cppclass NumberWrapper(Basic):
@@ -370,6 +372,7 @@ cdef extern from "<symengine/rational.h>" namespace "SymEngine":
     cdef RCP[const Number] from_mpq "SymEngine::Rational::from_mpq"(rational_class r) nogil
     cdef void get_num_den(const Rational &rat, const Ptr[RCP[Integer]] &num,
                      const Ptr[RCP[Integer]] &den) nogil
+    cdef RCP[const Number] rational(long n, long d) nogil
 
 cdef extern from "<symengine/complex.h>" namespace "SymEngine":
     cdef cppclass Complex(Number):