C++ Mathematical Expression Library (ExprTk) http://www.partow.net/programming/exprtk/index.html

exprtk_simple_example_07.cpp

@@ -48,9 +48,9 @@ void logic()
 
    for (int i = 0; i < 8; ++i)
    {
-      symbol_table.get_variable("A")->ref() = T(i & 0x01 ? 1 : 0);
+      symbol_table.get_variable("A")->ref() = T((i & 0x01) ? 1 : 0);
-      symbol_table.get_variable("B")->ref() = T(i & 0x02 ? 1 : 0);
+      symbol_table.get_variable("B")->ref() = T((i & 0x02) ? 1 : 0);
-      symbol_table.get_variable("C")->ref() = T(i & 0x04 ? 1 : 0);
+      symbol_table.get_variable("C")->ref() = T((i & 0x04) ? 1 : 0);
 
       int result = static_cast<int>(expression.value());
 

exprtk_simple_example_15.cpp

@@ -32,9 +32,9 @@ void black_scholes_merton_model()
                   " var d1 := (log(s / x) + (r + v^2 / 2) * t) / (v * sqrt(t)); "
                   " var d2 := d1 - v * sqrt(t);                                 "
                   "                                                             "
-                  " if(callput_flag == 'call')                                  "
+                  " if (callput_flag == 'call')                                 "
                   "   s * ncdf(d1) - x * e^(-r * t) * ncdf(d2);                 "
-                  " else if(callput_flag == 'put')                              "
+                  " else if (callput_flag == 'put')                             "
                   "   x * e^(-r * t) * ncdf(-d2) - s * ncdf(-d1);               "
                   "                                                             ";
 
@@ -66,6 +66,7 @@ void black_scholes_merton_model()
 
    {
       callput_flag = "call";
+
       T bsm = expression.value();
 
       printf("BSM(%s,%5.3f,%5.3f,%5.3f,%5.3f,%5.3f) = %10.6f\n",
@@ -76,6 +77,7 @@ void black_scholes_merton_model()
 
    {
       callput_flag = "put";
+
       T bsm = expression.value();
 
       printf("BSM(%s,%5.3f,%5.3f,%5.3f,%5.3f,%5.3f) = %10.6f\n",

exprtk_test.cpp

@@ -1193,7 +1193,7 @@ inline bool run_test00()
 template <typename T>
 struct test_xy
 {
-   test_xy(std::string e, const T& v0, const T& v1, const T& r)
+   test_xy(const std::string& e, const T& v0, const T& v1, const T& r)
    : expr(e),
      x(v0),
      y(v1),
@@ -1209,7 +1209,7 @@ struct test_xy
 template <typename T>
 struct test_xyzw
 {
-   test_xyzw(std::string e, const T& v0, const T& v1, const T& v2, const T& v3, const T& r)
+   test_xyzw(const std::string& e, const T& v0, const T& v1, const T& v2, const T& v3, const T& r)
    : expr(e),
      x(v0),
      y(v1),
@@ -1850,7 +1850,7 @@ inline bool run_test01()
 template <typename T>
 struct test_ab
 {
-   test_ab(std::string e, const std::string& v0, const std::string& v1, const T& r)
+   test_ab(const std::string& e, const std::string& v0, const std::string& v1, const T& r)
    : expr(e),
      a(v0),
      b(v1),
@@ -5341,6 +5341,35 @@ struct rem_space_and_uppercase : public exprtk::igeneric_function<T>
    }
 };
 
+template <typename T>
+struct vararg_func : public exprtk::igeneric_function<T>
+{
+   typedef typename exprtk::igeneric_function<T>::parameter_list_t
+                                                  parameter_list_t;
+
+   typedef typename exprtk::igeneric_function<T>::generic_type
+                                                  generic_type;
+
+   typedef typename generic_type::scalar_view scalar_t;
+   typedef typename generic_type::vector_view vector_t;
+
+   vararg_func()
+   : exprtk::igeneric_function<T>("Z|T*|V")
+   {}
+
+   inline T operator()(const std::size_t& ps_index, parameter_list_t /*arglist*/)
+   {
+      switch (ps_index)
+      {                         // Overload resolution:
+         case 0  : return T(0); // Z  - Zero arguments
+         case 1  : return T(1); // T* - One or more scalars
+         case 2  : return T(2); // V  - One vector
+         default : return std::numeric_limits<T>::quiet_NaN();
+      }
+   }
+};
+
+
 template <typename T>
 inline bool run_test18()
 {
@@ -5868,7 +5897,7 @@ inline bool run_test18()
 
          if (!parser.compile(program,expression))
          {
-            printf("Error: %s\tExpression: %s\n",
+            printf("run_test18() - Error: %s\tExpression: %s\n",
                    parser.error().c_str(),
                    program.c_str());
 
@@ -5931,6 +5960,77 @@ inline bool run_test18()
          return false;
    }
 
+   {
+      bool failure = false;
+
+      typedef exprtk::symbol_table<T> symbol_table_t;
+      typedef exprtk::expression<T>     expression_t;
+      typedef exprtk::parser<T>             parser_t;
+
+      symbol_table_t symbol_table;
+
+      T v[4] = {T(5), T(6), T(7), T(8)};
+
+      symbol_table.add_vector("v",v);
+
+      vararg_func<T> vaf;
+      symbol_table.add_function("vararg_func",vaf);
+
+      expression_t expression;
+      expression.register_symbol_table(symbol_table);
+
+      parser_t parser;
+
+      std::string programs[] =
+                     {
+                        "equal(0,vararg_func())",
+                        "equal(1,vararg_func() + 1)",
+                        "equal(1,1 + vararg_func())",
+                        "equal(1,vararg_func + 1)",
+                        "equal(1,1 + vararg_func)",
+                        "equal(0,vararg_func() + vararg_func)",
+                        "equal(0,vararg_func + vararg_func())",
+                        "equal(1,vararg_func + vararg_func(1))",
+                        "equal(1,vararg_func + vararg_func(1,2))",
+                        "equal(2,vararg_func + vararg_func(v))",
+                        "equal(1,vararg_func() + vararg_func(1))",
+                        "equal(1,vararg_func() + vararg_func(1,2))",
+                        "equal(2,vararg_func() + vararg_func(v))",
+                        "equal(2,vararg_func(v))",
+                        "equal(1,vararg_func(1))",
+                        "equal(1,vararg_func(1,2,3))",
+                        "equal(1,vararg_func(5,6,7,8))",
+                        "equal(5,vararg_func(v) + 3)",
+                        "equal(5,vararg_func(1) + 4)",
+                        "equal(6,vararg_func(1,2,3) + 5)",
+                        "equal(7,vararg_func(5,6,7,8) + 6)"
+                     };
+
+      static const std::size_t programs_size = sizeof(programs) / sizeof(std::string);
+
+      for (std::size_t i = 0; i < programs_size; ++i)
+      {
+         if (!parser.compile(programs[i],expression))
+         {
+            printf("run_test18() - Error: %s\tExpression: %s\n",
+                   parser.error().c_str(),
+                   programs[i].c_str());
+
+            failure = true;
+         }
+         else if (T(1) != expression.value())
+         {
+            printf("run_test18() - Error in evaluation! (5) Expression: %s\n",
+                   programs[i].c_str());
+
+            failure = true;
+         }
+      }
+
+      if (failure)
+         return false;
+   }
+
    return true;
 }
 

readme.txt

@@ -1334,23 +1334,23 @@ embedded into the expression.
 
 There are five types of function interface:
 
-   +---+----------------------+-------------+
+  +---+----------------------+-------------+----------------------+
-   | # |         Name         | Return Type |
+  | # |         Name         | Return Type | Input Types          |
-   +---+----------------------+-------------+
+  +---+----------------------+-------------+----------------------+
-   | 1 | ifunction            | Scalar      |
+  | 1 | ifunction            | Scalar      | Scalar               |
-   | 2 | ivararg_function     | Scalar      |
+  | 2 | ivararg_function     | Scalar      | Scalar               |
-   | 3 | igeneric_function    | Scalar      |
+  | 3 | igeneric_function    | Scalar      | Scalar,Vector,String |
-   | 4 | igeneric_function II | String      |
+  | 4 | igeneric_function II | String      | Scalar,Vector,String |
-   | 5 | function_compositor  | Scalar      |
+  | 5 | function_compositor  | Scalar      | Scalar               |
-   +---+----------------------+-------------+
+  +---+----------------------+-------------+----------------------+
-
 
 (1) ifunction
-This  interface  supports  zero  to  20  input  parameters.  The usage
+This interface supports zero to 20 input parameters of only the scalar
-requires a custom function be  derived from ifunction and to  override
+type (numbers). The  usage requires a custom function be  derived from
-one  of the  21 function  operators. As  part of  the constructor  the
+ifunction and to override one of the 21 function operators. As part of
-custom function will define how many parameters it expects to  handle.
+the constructor the custom function will define how many parameters it
-The following example defines a 3 parameter function called 'foo':
+expects  to  handle.  The  following  example  defines  a  3 parameter
+function called 'foo':
 
    template <typename T>
    struct foo : public exprtk::ifunction<T>
@@ -1366,8 +1366,8 @@ The following example defines a 3 parameter function called 'foo':
 
 
 (2) ivararg_function
-This interface supports a variable  number of arguments as input  into
+This interface supports a variable number of scalar arguments as input
-the  function.  The  function operator  interface  uses  a std::vector
+into the function. The function operator interface uses a  std::vector
 specialized upon type T to facilitate parameter passing. The following
 example defines a vararg function called 'boo':
 
@@ -1504,12 +1504,13 @@ listing of said characters and their meanings:
    (1) T - Scalar
    (2) V - Vector
    (3) S - String
-   (4) ? - Any type (Scalar, Vector or String)
+   (4) Z - Zero or no parameters
-   (5) * - Wildcard operator
+   (5) ? - Any type (Scalar, Vector or String)
-   (6) | - Parameter sequence delimiter
+   (6) * - Wildcard operator
+   (7) | - Parameter sequence delimiter
 
 
-No other characters other than  the six denoted above may  be included
+No other characters other than the seven denoted above may be included
 in the parameter sequence  definition. If any such  invalid characters
 do exist, registration of the associated generic function to a  symbol
 table ('add_function' method) will fail. If the parameter sequence  is
@@ -1545,6 +1546,12 @@ parameters in the following sequence:
    (3) Scalar
    (4) Scalar
 
+Note: The  'Z' or  no parameter option may not be  used in conjunction
+with any other type option in a parameter sequence. When  incorporated
+in the parameter sequence list, the no parameter option indicates that
+the function may be invoked  without any parameters being passed.  For
+more information refer to the section: 'Zero Parameter Functions'
+
 
 (4) igeneric_function II
 This interface is identical to  the igeneric_function, in that in  can
@@ -1851,6 +1858,11 @@ carried out:
       { ... }
    };
 
+
+Note: For  the igeneric_function  type, there  also needs  to be a 'Z'
+parameter sequence  defined inorder  for the  zero parameter  trait to
+properly take effect otherwise a compilation error will occur.
+
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 [16 - EXPRESSION DEPENDENTS]
@@ -2822,6 +2834,7 @@ the ExprTk header. The defines are as follows:
    (4) exprtk_disable_sc_andor
    (5) exprtk_disable_enhanced_features
    (6) exprtk_disable_string_capabilities
+   (7) exprtk_disable_superscalar_unroll
 
 
 (1) exprtk_enable_debugging
@@ -2854,6 +2867,14 @@ This  define  will  disable all  string  processing  capabilities. Any
 expression that contains a string or string related syntax will result
 in a compilation failure.
 
+(7) exprtk_disable_superscalar_unroll
+This define will set  the loop unroll batch  size to 4 operations  per
+loop  instead of  the default  8 operations.  This define  is used  in
+operations that  involve vectors  and aggregations  over vectors. When
+targeting  non-superscalar  architectures, it  may  be recommended  to
+build using this particular option if efficiency of evaluations is  of
+concern.
+
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 [23 - FILES]