extracted action

SpectraL519 · Jan 30, 2025 · 16e2e94 · 16e2e94
1 parent d0b43f2
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diff --git a/README.md b/README.md
@@ -210,21 +210,21 @@ Parameters which can be specified for both positional and optional arguments inc
 
   ```c++
   parser.add_optional_argument<double>("denominator", "d")
-        .action<ap::void_action>([](double& value) { value = 1. / value; });
+        .action<ap::action_type::modify>([](double& value) { value = 1. / value; });
   ```
 
   or en equivalent valued action:
 
   ```c++
   parser.add_optional_argument<double>("denominator", "d")
-        .action<ap::valued_action>([](const double& value) { return 1. / value; });
+        .action<ap::action_type::transform>([](const double& value) { return 1. / value; });
   ```
 
   Actions can also be used to perform some value checking logic, e.g. the predefined `check_file_exists` which checks if a file with a given name exists:
 
   ```c++
   parser.add_optional_argument("input", "i")
-        .action<ap::void_action>(ap::action::check_file_exists());
+        .action<ap::action_type::modify>(ap::action::check_file_exists());
   ```
 
 #### Optional argument specific parameters
@@ -307,7 +307,7 @@ The supported default arguments are:
   ```c++
   // equivalent to:
   parser.add_positional_argument<std::string>("input")
-        .action<ap::void_action>(ap::action::check_file_exists())
+        .action<ap::action_type::modify>(ap::action::check_file_exists())
         .help("Input file path");
   ```
 
@@ -343,14 +343,14 @@ The supported default arguments are:
   parser.add_optional_argument("input", "i")
         .required()
         .nargs(1)
-        .action<ap::void_action>(ap::action::check_file_exists())
+        .action<ap::action_type::modify>(ap::action::check_file_exists())
         .help("Input file path");
 
   // multi_input - equivalent to:
   parser.add_optional_argument("input", "i")
         .required()
         .nargs(ap::nargs::at_least(1))
-        .action<ap::void_action>(ap::action::check_file_exists())
+        .action<ap::action_type::modify>(ap::action::check_file_exists())
         .help("Input files paths");
   ```
 

diff --git a/include/ap/action/detail/utility.hpp b/include/ap/action/detail/utility.hpp
@@ -0,0 +1,34 @@
+#pragma once
+
+#include "ap/action/specifiers.hpp"
+
+namespace ap::action::detail {
+
+/**
+ * @brief The concept is satisfied when `AS` is either a valued or void argument action
+ * @tparam AS The action specifier type.
+ */
+template <typename AS>
+concept c_action_specifier = ap::detail::c_one_of<AS, action_type::transform, action_type::modify>;
+
+/// @brief Template argument action callable type alias.
+template <c_action_specifier AS, ap::detail::c_argument_value_type T>
+using callable_type = typename AS::template type<T>;
+
+/// @brief Template argument action callabla variant type alias.
+template <ap::detail::c_argument_value_type T>
+using action_variant_type =
+    std::variant<callable_type<action_type::transform, T>, callable_type<action_type::modify, T>>;
+
+/**
+ * @brief Checks if an argument action variant holds a void action.
+ * @tparam T The argument value type.
+ * @param action The action variant.
+ * @return True if the held action is a void action.
+ */
+template <ap::detail::c_argument_value_type T>
+[[nodiscard]] constexpr inline bool is_void_action(const action_variant_type<T>& action) noexcept {
+    return std::holds_alternative<callable_type<action_type::modify, T>>(action);
+}
+
+} // namespace ap::action::detail
diff --git a/include/ap/action/predefined_actions.hpp b/include/ap/action/predefined_actions.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "ap/error/exceptions.hpp"
+#include "detail/utility.hpp"
+
+#include <filesystem>
+
+namespace ap::action {
+
+/// @brief Returns a default argument action.
+template <ap::detail::c_argument_value_type T>
+detail::callable_type<ap::action_type::modify, T> none() noexcept {
+    return [](T&) {};
+}
+
+/// @brief Returns a predefined action for file name handling arguments. Checks whether a file with the given name exists.
+inline detail::callable_type<ap::action_type::modify, std::string> check_file_exists() noexcept {
+    return [](std::string& file_path) {
+        if (not std::filesystem::exists(file_path))
+            throw argument_parser_exception(std::format("File `{}` does not exists!", file_path));
+    };
+}
+
+} // namespace ap::action
diff --git a/include/ap/action/specifiers.hpp b/include/ap/action/specifiers.hpp
@@ -0,0 +1,39 @@
+#pragma once
+
+#include "ap/detail/concepts.hpp"
+
+#include <functional>
+
+namespace ap::action_type {
+
+// TODO:
+// * on_read_action
+// * on_flag_action
+
+/*
+ * @brief Represents a transformating action.
+ *
+ * Represents an argument action which transforms the parsed value and
+ * returns a new value with which the argument will be initialized.
+ */
+struct transform {
+    template <ap::detail::c_argument_value_type T>
+    using type = std::function<T(const T&)>;
+};
+
+/*
+ * @brief Represents a modifying action.
+ *
+ * Represents an argument action which modifies the value of an
+ * already initialized argument.
+ *
+ * NOTE: The modify action doesn't have to actually modify the
+ * underlying value - it can simply perform some action on it.
+ * Example: `ap::action::check_file_exists`
+ */
+struct modify {
+    template <ap::detail::c_argument_value_type T>
+    using type = std::function<void(T&)>;
+};
+
+} // namespace ap::action_type
diff --git a/include/ap/argument_parser.hpp b/include/ap/argument_parser.hpp
@@ -36,6 +36,8 @@ SOFTWARE.
 
 #pragma once
 
+#include "action/predefined_actions.hpp"
+#include "action/specifiers.hpp"
 #include "detail/argument_interface.hpp"
 #include "detail/argument_name.hpp"
 #include "detail/concepts.hpp"
@@ -73,73 +75,6 @@ struct argument_parser_test_fixture;
 
 namespace ap {
 
-/// @brief Defines valued argument action traits.
-struct valued_action {
-    template <ap::detail::c_argument_value_type T>
-    using type = std::function<T(const T&)>;
-};
-
-/// @brief Defines void argument action traits.
-struct void_action {
-    template <ap::detail::c_argument_value_type T>
-    using type = std::function<void(T&)>;
-};
-
-// TODO:
-// * on_read_action
-// * on_flag_action
-
-/// @brief Argument action handling utility.
-namespace action {
-
-/// @brief Internal argument action handling utility
-namespace detail {
-
-/**
- * @brief The concept is satisfied when `AS` is either a valued or void argument action
- * @tparam AS The action specifier type.
- */
-template <typename AS>
-concept c_action_specifier = ap::detail::c_one_of<AS, ap::valued_action, ap::void_action>;
-
-/// @brief Template argument action callable type alias.
-template <c_action_specifier AS, ap::detail::c_argument_value_type T>
-using callable_type = typename AS::template type<T>;
-
-/// @brief Template argument action callabla variant type alias.
-template <ap::detail::c_argument_value_type T>
-using action_variant_type =
-    std::variant<callable_type<ap::valued_action, T>, callable_type<ap::void_action, T>>;
-
-/**
- * @brief Checks if an argument action variant holds a void action.
- * @tparam T The argument value type.
- * @param action The action variant.
- * @return True if the held action is a void action.
- */
-template <ap::detail::c_argument_value_type T>
-[[nodiscard]] constexpr inline bool is_void_action(const action_variant_type<T>& action) noexcept {
-    return std::holds_alternative<callable_type<ap::void_action, T>>(action);
-}
-
-} // namespace detail
-
-/// @brief Returns a default argument action.
-template <ap::detail::c_argument_value_type T>
-detail::callable_type<ap::void_action, T> default_action() noexcept {
-    return [](T&) {};
-}
-
-/// @brief Returns a predefined action for file name handling arguments. Checks whether a file with the given name exists.
-inline detail::callable_type<ap::void_action, std::string> check_file_exists() noexcept {
-    return [](std::string& file_path) {
-        if (not std::filesystem::exists(file_path))
-            throw argument_parser_exception(std::format("File `{}` does not exists!", file_path));
-    };
-}
-
-} // namespace action
-
 /// @brief Namespace containing classes and utilities for handling command-line arguments.
 namespace argument {
 
@@ -334,11 +269,13 @@ class positional_argument : public ap::detail::argument_interface {
     void _apply_action(value_type& value) const noexcept {
         namespace action = ap::action::detail;
         if (action::is_void_action(this->_action))
-            std::get<action::callable_type<ap::void_action, value_type>>(this->_action)(value);
+            std::get<action::callable_type<ap::action_type::modify, value_type>>(this->_action)(
+                value
+            );
         else
-            value =
-                std::get<action::callable_type<ap::valued_action, value_type>>(this->_action)(value
-                );
+            value = std::get<
+                action::callable_type<ap::action_type::transform, value_type>>(this->_action)(value
+            );
     }
 
     using action_type = ap::action::detail::action_variant_type<T>;
@@ -351,8 +288,8 @@ class positional_argument : public ap::detail::argument_interface {
     static constexpr bool _bypass_required =
         false; ///< Bypassing required status is defaultly not allowed for positional arguments.
     std::vector<value_type> _choices; ///< Vector of valid choices for the positional argument.
-    action_type _action = ap::action::default_action<value_type>(
-    ); ///< Action associated with the positional argument.
+    action_type _action =
+        ap::action::none<value_type>(); ///< Action associated with the positional argument.
 
     std::any _value; ///< Stored value of the positional argument.
 
@@ -643,11 +580,13 @@ class optional_argument : public ap::detail::argument_interface {
     void _apply_action(value_type& value) const noexcept {
         namespace action = ap::action::detail;
         if (action::is_void_action(this->_action))
-            std::get<action::callable_type<ap::void_action, value_type>>(this->_action)(value);
+            std::get<action::callable_type<ap::action_type::modify, value_type>>(this->_action)(
+                value
+            );
         else
-            value =
-                std::get<action::callable_type<ap::valued_action, value_type>>(this->_action)(value
-                );
+            value = std::get<
+                action::callable_type<ap::action_type::transform, value_type>>(this->_action)(value
+            );
     }
 
     using action_type = ap::action::detail::action_variant_type<T>;
@@ -660,7 +599,7 @@ class optional_argument : public ap::detail::argument_interface {
     bool _bypass_required = false;
     std::optional<ap::nargs::range> _nargs_range;
     action_type _action =
-        ap::action::default_action<value_type>(); ///< Action associated with the opitonal argument.
+        ap::action::none<value_type>(); ///< Action associated with the opitonal argument.
     std::vector<value_type> _choices; ///< Vector of valid choices for the optional argument.
     std::any _default_value;
     std::any _implicit_value;
@@ -985,7 +924,7 @@ class argument_parser {
         switch (arg_discriminator) {
         case default_posarg::input:
             this->add_positional_argument("input")
-                .action<ap::void_action>(ap::action::check_file_exists())
+                .action<action_type::modify>(action::check_file_exists())
                 .help("Input file path");
             break;
 
@@ -1009,7 +948,7 @@ class argument_parser {
             this->add_optional_argument("input", "i")
                 .required()
                 .nargs(1)
-                .action<ap::void_action>(ap::action::check_file_exists())
+                .action<action_type::modify>(action::check_file_exists())
                 .help("Input file path");
             break;
 
@@ -1021,7 +960,7 @@ class argument_parser {
             this->add_optional_argument("input", "i")
                 .required()
                 .nargs(ap::nargs::at_least(1))
-                .action<ap::void_action>(ap::action::check_file_exists())
+                .action<action_type::modify>(action::check_file_exists())
                 .help("Input files paths");
             break;
 

diff --git a/tests/source/test_optional_argument.cpp b/tests/source/test_optional_argument.cpp
@@ -358,7 +358,7 @@ TEST_CASE_FIXTURE(
 
     SUBCASE("valued action") {
         const auto double_valued_action = [](const test_value_type& value) { return 2 * value; };
-        sut.action<ap::valued_action>(double_valued_action);
+        sut.action<ap::action_type::transform>(double_valued_action);
 
         sut_set_value(sut, std::to_string(value_1));
 
@@ -367,7 +367,7 @@ TEST_CASE_FIXTURE(
 
     SUBCASE("void action") {
         const auto double_void_action = [](test_value_type& value) { value *= 2; };
-        sut.action<ap::void_action>(double_void_action);
+        sut.action<ap::action_type::modify>(double_void_action);
 
         auto test_value = value_1;
 

diff --git a/tests/source/test_positional_argument.cpp b/tests/source/test_positional_argument.cpp
@@ -222,7 +222,7 @@ TEST_CASE_FIXTURE(
 
     SUBCASE("valued action") {
         const auto double_valued_action = [](const test_value_type& value) { return 2 * value; };
-        sut.action<ap::valued_action>(double_valued_action);
+        sut.action<ap::action_type::transform>(double_valued_action);
 
         sut_set_value(sut, std::to_string(value_1));
 
@@ -231,7 +231,7 @@ TEST_CASE_FIXTURE(
 
     SUBCASE("void action") {
         const auto double_void_action = [](test_value_type& value) { value *= 2; };
-        sut.action<ap::void_action>(double_void_action);
+        sut.action<ap::action_type::modify>(double_void_action);
 
         auto test_value = value_1;