[Kinetics] deprecate magic numbers for falloff reactions

include/cantera/kinetics/Falloff.h

@@ -5,6 +5,7 @@
 #define CT_FALLOFF_H
 
 #include "cantera/kinetics/reaction_defs.h"
+#include "cantera/base/global.h"
 
 namespace Cantera
 {
@@ -74,8 +75,18 @@ class Falloff
         return 0;
     }
 
+    //! Return a string representing the type of the Falloff parameterization.
+    virtual std::string type() const {
+        return "Falloff";
+    }
+
     //! Return an integer representing the type of the Falloff parameterization.
+    /*!
+     * @deprecated To be removed after Cantera 2.5.
+     */
     virtual int getType() const {
+        warn_deprecated("Falloff::getType()",
+            "Replaced by Falloff::type(). To be removed after Cantera 2.5.");
         return SIMPLE_FALLOFF;
     }
 
@@ -146,7 +157,13 @@ class Troe : public Falloff
         return 1;
     }
 
+    virtual std::string type() const {
+        return "Troe";
+    }
+
     virtual int getType() const {
+        warn_deprecated("Troe::getType()",
+            "Replaced by Troe::type(). To be removed after Cantera 2.5.");
         return TROE_FALLOFF;
     }
 
@@ -220,7 +237,13 @@ class SRI : public Falloff
         return 2;
     }
 
+    virtual std::string type() const {
+        return "SRI";
+    }
+
     virtual int getType() const {
+        warn_deprecated("SRI::getType()",
+            "Replaced by SRI::type(). To be removed after Cantera 2.5.");
         return SRI_FALLOFF;
     }
 

include/cantera/kinetics/FalloffFactory.h

@@ -58,9 +58,23 @@ class FalloffFactory : public Factory<Falloff>
      * @param c    input vector of doubles which populates the falloff
      *             parameterization.
      * @returns    a pointer to a new Falloff class.
+     *
+     * @deprecated To be removed after Cantera 2.5.
      */
     virtual Falloff* newFalloff(int type, const vector_fp& c);
 
+    //! Return a pointer to a new falloff function calculator.
+    /*!
+     * @param string String identifier specifying the type of falloff function.
+     *              The standard types match class names defined in Falloff.h.
+     *              A factory class derived from FalloffFactory may define other
+     *              types as well.
+     * @param c    input vector of doubles which populates the falloff
+     *             parameterization.
+     * @returns    a pointer to a new Falloff class.
+     */
+    virtual Falloff* newFalloff(std::string type, const vector_fp& c);
+
 private:
     //! Pointer to the single instance of the factory
     static FalloffFactory* s_factory;
@@ -73,7 +87,13 @@ class FalloffFactory : public Factory<Falloff>
 };
 
 //! @copydoc FalloffFactory::newFalloff
+/*!
+ * @deprecated To be removed after Cantera 2.5.
+ */
 shared_ptr<Falloff> newFalloff(int type, const vector_fp& c);
 
+//! @copydoc FalloffFactory::newFalloff
+shared_ptr<Falloff> newFalloff(std::string type, const vector_fp& c);
+
 }
 #endif

include/cantera/kinetics/reaction_defs.h

@@ -134,6 +134,9 @@ const int CHEBYSHEV_REACTION_RATECOEFF_TYPE = 8;
 //@}
 
 /** @name Falloff Function Types
+ *
+ * Magic numbers
+ * @deprecated To be removed after Cantera 2.5.
  */
 //@{
 const int SIMPLE_FALLOFF = 100;

interfaces/cython/cantera/_cantera.pxd

@@ -324,7 +324,7 @@ cdef extern from "cantera/kinetics/Reaction.h" namespace "Cantera":
         size_t workSize()
 
         size_t nParameters()
-        int getType()
+        string type()
         void getParameters(double*)
 
     cdef cppclass CxxFalloffReaction "Cantera::FalloffReaction" (CxxReaction):
@@ -375,7 +375,7 @@ cdef extern from "cantera/kinetics/Reaction.h" namespace "Cantera":
         string sticking_species
 
 cdef extern from "cantera/kinetics/FalloffFactory.h" namespace "Cantera":
-    cdef shared_ptr[CxxFalloff] CxxNewFalloff "Cantera::newFalloff" (int, vector[double]) except +
+    cdef shared_ptr[CxxFalloff] CxxNewFalloff "Cantera::newFalloff" (string, vector[double]) except +translate_exception
 
 cdef extern from "cantera/kinetics/Kinetics.h" namespace "Cantera":
     cdef cppclass CxxKinetics "Cantera::Kinetics":

interfaces/cython/cantera/reaction.pyx

@@ -10,10 +10,6 @@ cdef extern from "cantera/kinetics/reaction_defs.h" namespace "Cantera":
     cdef int CHEMACT_RXN
     cdef int INTERFACE_RXN
 
-    cdef int SIMPLE_FALLOFF
-    cdef int TROE_FALLOFF
-    cdef int SRI_FALLOFF
-
 
 cdef class Reaction:
     """
@@ -422,7 +418,7 @@ cdef class Falloff:
     :param init:
         Used internally when wrapping :ct:`Falloff` objects returned from C++.
     """
-    falloff_type = SIMPLE_FALLOFF
+    falloff_type = "Falloff"
 
     def __cinit__(self, params=(), init=True):
         if not init:
@@ -431,21 +427,13 @@ cdef class Falloff:
         cdef vector[double] c
         for p in params:
             c.push_back(p)
-        self._falloff = CxxNewFalloff(self.falloff_type, c)
+        self._falloff = CxxNewFalloff(stringify(self.falloff_type), c)
         self.falloff = self._falloff.get()
 
     property type:
         """ A string defining the type of the falloff parameterization """
         def __get__(self):
-            cdef int falloff_type = self.falloff.getType()
-            if falloff_type == SIMPLE_FALLOFF:
-                return "Simple"
-            elif falloff_type == TROE_FALLOFF:
-                return "Troe"
-            elif falloff_type == SRI_FALLOFF:
-                return "SRI"
-            else:
-                return "unknown"
+            return pystr(self.falloff.type())
 
     property parameters:
         """ The array of parameters used to define this falloff function. """
@@ -474,7 +462,7 @@ cdef class TroeFalloff(Falloff):
         An array of 3 or 4 parameters: :math:`[a, T^{***}, T^*, T^{**}]` where
         the final parameter is optional (with a default value of 0).
     """
-    falloff_type = TROE_FALLOFF
+    falloff_type = "Troe"
 
 
 cdef class SriFalloff(Falloff):
@@ -486,16 +474,16 @@ cdef class SriFalloff(Falloff):
         two parameters are optional (with default values of 1 and 0,
         respectively).
     """
-    falloff_type = SRI_FALLOFF
+    falloff_type = "SRI"
 
 
 cdef wrapFalloff(shared_ptr[CxxFalloff] falloff):
-    cdef int falloff_type = falloff.get().getType()
-    if falloff_type == SIMPLE_FALLOFF:
+    falloff_type = pystr(falloff.get().type())
+    if falloff_type == "Falloff":
         f = Falloff(init=False)
-    elif falloff_type == TROE_FALLOFF:
+    elif falloff_type == "Troe":
         f = TroeFalloff(init=False)
-    elif falloff_type == SRI_FALLOFF:
+    elif falloff_type == "SRI":
         f = SriFalloff(init=False)
     else:
         warnings.warn('Unknown falloff type: {0}'.format(falloff_type))

src/kinetics/FalloffFactory.cpp

@@ -23,6 +23,9 @@ FalloffFactory::FalloffFactory()
 
 Falloff* FalloffFactory::newFalloff(int type, const vector_fp& c)
 {
+    warn_deprecated("FalloffFactory::newFalloff",
+        "Instantiation using magic numbers is deprecated; use string "
+        "identifier instead. To be removed after Cantera 2.5.");
     static const std::unordered_map<int, std::string> types {
         {SIMPLE_FALLOFF, "Simple"},
         {TROE_FALLOFF, "Troe"},
@@ -34,10 +37,23 @@ Falloff* FalloffFactory::newFalloff(int type, const vector_fp& c)
     return f;
 }
 
+Falloff* FalloffFactory::newFalloff(std::string type, const vector_fp& c)
+{
+    Falloff* f = create(type);
+    f->init(c);
+    return f;
+}
+
 shared_ptr<Falloff> newFalloff(int type, const vector_fp& c)
 {
     shared_ptr<Falloff> f(FalloffFactory::factory()->newFalloff(type, c));
     return f;
 }
 
+shared_ptr<Falloff> newFalloff(std::string type, const vector_fp& c)
+{
+    shared_ptr<Falloff> f(FalloffFactory::factory()->newFalloff(type, c));
+    return f;
+}
+
 }

src/kinetics/Reaction.cpp

@@ -359,30 +359,28 @@ void readFalloff(FalloffReaction& R, const XML_Node& rc_node)
         falloff_parameters.push_back(fpValueCheck(p[n]));
     }
 
-    int falloff_type = 0;
     if (caseInsensitiveEquals(falloff["type"], "lindemann")) {
-        falloff_type = SIMPLE_FALLOFF;
         if (np != 0) {
             throw CanteraError("readFalloff", "Lindemann parameterization "
                 "takes no parameters, but {} were given", np);
         }
+        R.falloff = newFalloff("Simple", falloff_parameters);
     } else if (caseInsensitiveEquals(falloff["type"], "troe")) {
-        falloff_type = TROE_FALLOFF;
         if (np != 3 && np != 4) {
             throw CanteraError("readFalloff", "Troe parameterization takes "
                 "3 or 4 parameters, but {} were given", np);
         }
+        R.falloff = newFalloff("Troe", falloff_parameters);
     } else if (caseInsensitiveEquals(falloff["type"], "sri")) {
-        falloff_type = SRI_FALLOFF;
         if (np != 3 && np != 5) {
             throw CanteraError("readFalloff", "SRI parameterization takes "
                 "3 or 5 parameters, but {} were given", np);
         }
+        R.falloff = newFalloff("SRI", falloff_parameters);
     } else {
         throw CanteraError("readFalloff", "Unrecognized falloff type: '{}'",
                            falloff["type"]);
     }
-    R.falloff = newFalloff(falloff_type, falloff_parameters);
 }
 
 void readFalloff(FalloffReaction& R, const AnyMap& node)
@@ -395,7 +393,7 @@ void readFalloff(FalloffReaction& R, const AnyMap& node)
             f["T1"].asDouble(),
             f.getDouble("T2", 0.0)
         };
-        R.falloff = newFalloff(TROE_FALLOFF, params);
+        R.falloff = newFalloff("Troe", params);
     } else if (node.hasKey("SRI")) {
         auto& f = node["SRI"].as<AnyMap>();
         vector_fp params{
@@ -405,9 +403,9 @@ void readFalloff(FalloffReaction& R, const AnyMap& node)
             f.getDouble("D", 1.0),
             f.getDouble("E", 0.0)
         };
-        R.falloff = newFalloff(SRI_FALLOFF, params);
+        R.falloff = newFalloff("SRI", params);
     } else {
-        R.falloff = newFalloff(SIMPLE_FALLOFF, {});
+        R.falloff = newFalloff("Simple", {});
     }
 }
 

test/kinetics/kineticsFromScratch.cpp

@@ -118,7 +118,7 @@ TEST_F(KineticsFromScratch, add_falloff_reaction)
     ThirdBody tbody;
     tbody.efficiencies = parseCompString("AR:0.7 H2:2.0 H2O:6.0");
     auto R = make_shared<FalloffReaction>(reac, prod, low_rate, high_rate, tbody);
-    R->falloff = newFalloff(TROE_FALLOFF, falloff_params);
+    R->falloff = newFalloff("Troe", falloff_params);
     kin.addReaction(R);
     check_rates(2);
 }