Merge pull request #576 from chros73/simple_math_commands

Add support for basic arithmetic operators

rak/algorithm.h

@@ -176,6 +176,26 @@ inline int popcount_wrapper(T t) {
 #endif
 }
 
+// Get the median of an unordered set of numbers of arbitrary
+// type by modifing the underlying dataset
+template <typename T = double, typename _InputIter>
+T median(_InputIter __first, _InputIter __last) {
+  T __med;
+
+  unsigned int __size = __last - __first;
+  unsigned int __middle = __size / 2;
+  _InputIter __target1 = __first + __middle;
+  std::nth_element(__first, __target1, __last);
+  __med = *__target1;
+
+  if (__size % 2 == 0) {
+    _InputIter __target2 = std::max_element(__first, __target1);
+    __med = (__med + *__target2) / 2.0;
+  }
+
+  return __med;
+}
+
 }
 
 #endif

src/command_ui.cc

@@ -39,6 +39,7 @@
 #include <sys/types.h>
 
 #include <ctime>
+#include <rak/algorithm.h>
 #include <rak/functional.h>
 #include <rak/functional_fun.h>
 
@@ -519,6 +520,128 @@ apply_elapsed_greater(const torrent::Object::list_type& args) {
   return (int64_t)(start_time != 0 && rak::timer::current_seconds() - start_time > rpc::convert_to_value(args.back()));
 }
 
+inline std::vector<int64_t>
+as_vector(const torrent::Object::list_type& args) {
+  if (args.size() == 0)
+    throw torrent::input_error("Wrong argument count in as_vector.");
+
+  std::vector<int64_t> result;
+
+  for (torrent::Object::list_const_iterator itr = args.begin(), last = args.end(); itr != last; itr++) {
+
+    if (itr->is_value()) {
+      result.push_back(itr->as_value());
+    } else if (itr->is_string()) {
+      result.push_back(rpc::convert_to_value(itr->as_string()));
+    } else if (itr->is_list()) {
+      std::vector<int64_t> subResult = as_vector(itr->as_list());
+      result.insert(result.end(), subResult.begin(), subResult.end());
+    } else {
+      throw torrent::input_error("Wrong type supplied to as_vector.");
+    }
+
+  }
+
+  return result;
+}
+
+int64_t
+apply_math_basic(const char* name, const std::function<int64_t(int64_t,int64_t)> op, const torrent::Object::list_type& args) {
+  int64_t val = 0, rhs = 0;
+  bool divides = !strcmp(name, "math.div") || !strcmp(name, "math.mod");
+
+  if (args.size() == 0)
+    throw torrent::input_error(std::string(name) + ": No arguments provided!");
+
+  for (torrent::Object::list_const_iterator itr = args.begin(), last = args.end(); itr != last; itr++) {
+
+    if (itr->is_value()) {
+      rhs = itr->as_value();
+    } else if (itr->is_string()) {
+      rhs = rpc::convert_to_value(itr->as_string());
+    } else if (itr->is_list()) {
+      rhs = apply_math_basic(name, op, itr->as_list());
+    } else {
+      throw torrent::input_error(std::string(name) + ": Wrong argument type");
+    }
+
+    if (divides && !rhs && itr != args.begin())
+      throw torrent::input_error(std::string(name) + ": Division by zero!");
+
+    val = itr == args.begin() ? rhs : op(val, rhs);
+
+  }
+
+  return val;
+}
+
+int64_t
+apply_arith_basic(const std::function<int64_t(int64_t,int64_t)> op, const torrent::Object::list_type& args) {
+  if (args.size() == 0)
+    throw torrent::input_error("Wrong argument count in apply_arith_basic.");
+
+  int64_t val = 0;
+
+  for (torrent::Object::list_const_iterator itr = args.begin(), last = args.end(); itr != last; itr++) {
+
+    if (itr->is_value()) {
+      val = itr == args.begin() ? itr->as_value() : (op(val, itr->as_value()) ? val : itr->as_value());
+    } else if (itr->is_string()) {
+      int64_t cval = rpc::convert_to_value(itr->as_string());
+      val = itr == args.begin() ? cval : (op(val, cval) ? val : cval);
+    } else if (itr->is_list()) {
+      int64_t fval = apply_arith_basic(op, itr->as_list());
+      val = itr == args.begin() ? fval : (op(val, fval) ? val : fval);
+    } else {
+      throw torrent::input_error("Wrong type supplied to apply_arith_basic.");
+    }
+
+  }
+
+  return val;
+}
+
+int64_t
+apply_arith_count(const torrent::Object::list_type& args) {
+  if (args.size() == 0)
+    throw torrent::input_error("Wrong argument count in apply_arith_count.");
+
+  int64_t val = 0;
+
+  for (torrent::Object::list_const_iterator itr = args.begin(), last = args.end(); itr != last; itr++) {
+
+    switch (itr->type()) {
+    case torrent::Object::TYPE_VALUE:
+    case torrent::Object::TYPE_STRING:
+      val++;
+      break;
+    case torrent::Object::TYPE_LIST:
+      val += apply_arith_count(itr->as_list());
+      break;
+    default:
+      throw torrent::input_error("Wrong type supplied to apply_arith_count.");
+    }
+
+  }
+
+  return val;
+}
+
+int64_t
+apply_arith_other(const char* op, const torrent::Object::list_type& args) {
+  if (args.size() == 0)
+    throw torrent::input_error("Wrong argument count in apply_arith_other.");
+
+  if (strcmp(op, "average") == 0) {
+    return (int64_t)(apply_math_basic(op, std::plus<int64_t>(), args) / apply_arith_count(args));
+  } else if (strcmp(op, "median") == 0) {
+    std::vector<int64_t> result = as_vector(args);
+    return (int64_t)rak::median(result.begin(), result.end());
+  } else {
+    throw torrent::input_error("Wrong operation supplied to apply_arith_other.");
+  }
+}
+
 void
 initialize_command_ui() {
   CMD2_VAR_STRING("keys.layout", "qwerty");
@@ -585,6 +708,17 @@ initialize_command_ui() {
   CMD2_ANY_VALUE("convert.xb",           std::bind(&apply_to_xb, std::placeholders::_2));
   CMD2_ANY_VALUE("convert.throttle",     std::bind(&apply_to_throttle, std::placeholders::_2));
 
+  CMD2_ANY_LIST("math.add",              std::bind(&apply_math_basic, "math.add", std::plus<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.sub",              std::bind(&apply_math_basic, "math.sub", std::minus<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.mul",              std::bind(&apply_math_basic, "math.mul", std::multiplies<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.div",              std::bind(&apply_math_basic, "math.div", std::divides<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.mod",              std::bind(&apply_math_basic, "math.mod", std::modulus<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.min",              std::bind(&apply_arith_basic, std::less<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.max",              std::bind(&apply_arith_basic, std::greater<int64_t>(), std::placeholders::_2));
+  CMD2_ANY_LIST("math.cnt",              std::bind(&apply_arith_count, std::placeholders::_2));
+  CMD2_ANY_LIST("math.avg",              std::bind(&apply_arith_other, "average", std::placeholders::_2));
+  CMD2_ANY_LIST("math.med",              std::bind(&apply_arith_other, "median", std::placeholders::_2));
+
   CMD2_ANY_LIST ("elapsed.less",         std::bind(&apply_elapsed_less, std::placeholders::_2));
   CMD2_ANY_LIST ("elapsed.greater",      std::bind(&apply_elapsed_greater, std::placeholders::_2));
 }