[Python] Added basic implementation of Func1 and its children

interfaces/cython/cantera/_cantera.pxd

@@ -46,6 +46,15 @@ cdef extern from "cantera/equil/MultiPhase.h" namespace "Cantera":
         void setPressure(double)
         double pressure()
 
+cdef extern from "cantera/numerics/Func1.h":
+    cdef cppclass CxxFunc1 "Cantera::Func1":
+        CxxFunc1()
+        double eval(double)
+        string write(string)
+
+    cdef cppclass CxxSin1 "Cantera::Sin1":
+        CxxSin1(double)
+
 cdef extern from "cantera/thermo/ThermoFactory.h" namespace "Cantera":
     cdef CxxThermoPhase* newPhase(string, string) except +
     cdef CxxThermoPhase* newPhase(XML_Node&) except +
@@ -67,3 +76,6 @@ cdef class _SolutionBase:
 cdef class Mixture:
     cdef CxxMultiPhase* mix
     cdef list _phases
+
+cdef class Func1:
+    cdef CxxFunc1* func

interfaces/cython/cantera/_cantera.pyx

@@ -7,6 +7,7 @@ from _cantera cimport *
 
 include "utils.pyx"
 include "constants.pyx"
+include "func1.pyx"
 
 include "base.pyx"
 include "thermo.pyx"

interfaces/cython/cantera/func1.pyx

@@ -0,0 +1,20 @@
+cdef class Func1:
+    def __cinit__(self, *args, **kwargs):
+        self.func = NULL # derived classes should allocate this object
+
+    def __dealloc__(self):
+        del self.func
+
+    def __init__(self, *args, **kwargs):
+        assert self.func != NULL
+
+    def __call__(self, t):
+        return self.func.eval(t)
+
+    def __str__(self):
+        cdef bytes s = self.func.write(stringify("t")).c_str()
+        return s.decode()
+
+cdef class Sin1(Func1):
+    def __cinit__(self, freq):
+        self.func = <CxxFunc1*>(new CxxSin1(freq))