YT-CPPAP-37: Greedy arguments

- Extended the `argument` class with a `bool _greedy`  member (`false` by default)
- Added a `greedy(bool)` setter method to the `argument` class.
- Aligned the parsing logic to assign all values to a greedy argument (after it's encountered) until its upper `nargs` range is reached

Author: SpectraL519

CMakeLists.txt

@@ -7,7 +7,7 @@ else()
 endif()
 
 project(cpp-ap
-    VERSION 3.0.0.5
+    VERSION 3.0.0.6
     DESCRIPTION "Command-line argument parser for C++20"
     HOMEPAGE_URL "https://github.com/SpectraL519/cpp-ap"
     LANGUAGES CXX

Doxyfile

@@ -48,7 +48,7 @@ PROJECT_NAME           = CPP-AP
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 3.0.0.5
+PROJECT_NUMBER         = 3.0.0.6
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

MODULE.bazel

@@ -1,4 +1,4 @@
 module(
     name = "cpp-ap",
-    version = "3.0.0.5",
+    version = "3.0.0.6",
 )

README.md

@@ -54,8 +54,8 @@ Command-line argument parser for C++20
   - [The Parser Class](/docs/tutorial.md#the-parser-class)
   - [Adding Arguments](/docs/tutorial.md#adding-arguments)
   - [Argument Parameters](/docs/tutorial.md#argument-parameters)
-    - [Common Parameters](/docs/tutorial.md##common-parameters)
-    - [Parameters Specific for Optional Arguments](/docs/tutorial.md##parameters-specific-for-optional-arguments)
+    - [Common Parameters](/docs/tutorial.md#common-parameters)
+    - [Parameters Specific for Optional Arguments](/docs/tutorial.md#parameters-specific-for-optional-arguments)
   - [Default Arguments](/docs/tutorial.md#default-arguments)
   - [Parsing Arguments](/docs/tutorial.md#parsing-arguments)
     - [Basic Argument Parsing Rules](/docs/tutorial.md#basic-argument-parsing-rules)

docs/tutorial.md

@@ -8,7 +8,18 @@
 - [Adding Arguments](#adding-arguments)
 - [Argument Parameters](#argument-parameters)
   - [Common Parameters](#common-parameters)
+    - [help](#1-help---the-arguments-description-which-will-be-printed-when-printing-the-parser-class-instance)
+    - [hidden](#2-hidden---if-this-option-is-set-for-an-argument-then-it-will-not-be-included-in-the-program-description)
+    - [required](#3-required---if-this-option-is-set-for-an-argument-and-its-value-is-not-passed-in-the-command-line-an-exception-will-be-thrown)
+    - [bypass required](#4-bypass_required---if-this-option-is-set-for-an-argument-the-required-option-for-other-arguments-will-be-discarded-if-the-bypassing-argument-is-used-in-the-command-line)
+    - [nargs](#5-nargs---sets-the-allowed-number-of-values-to-be-parsed-for-an-argument)
+    - [greedy](#6-greedy---if-this-option-is-set-the-argument-will-consume-all-command-line-values-until-its-upper-nargs-bound-is-reached)
+    - [choices](#7-choices---a-list-of-valid-argument-values)
+    - [value actions](#8-value-actions---functions-that-are-called-after-parsing-an-arguments-value)
+    - [default values](#9-default_values---a-list-of-values-which-will-be-used-if-no-values-for-an-argument-have-been-parsed)
   - [Parameters Specific for Optional Arguments](#parameters-specific-for-optional-arguments)
+    - [on-flag actions](#1-on-flag-actions---functions-that-are-called-immediately-after-parsing-an-arguments-flag)
+    - [implicit values](#2-implicit_values---a-list-of-values-which-will-be-set-for-an-argument-if-only-its-flag-but-no-values-are-parsed-from-the-command-line)
 - [Predefined Parameter Values](#predefined-parameter-values)
 - [Default Arguments](#default-arguments)
 - [Parsing Arguments](#parsing-arguments)
@@ -189,9 +200,10 @@ parser.add_<positional/optional>_argument<value_type>("argument", "a");
 >
 > - If the argument's value type is `ap::none_type`, the argument will not accept any values and therefore no value-related parameters can be set for such argument. This includes:
 >   - [nargs](#5-nargs---sets-the-allowed-number-of-values-to-be-parsed-for-an-argument-this-can-be-set-as-a)
->   - [choices](#6-choices---a-list-of-valid-argument-values)
->   - [value actions](#7-value-actions---function-performed-after-parsing-an-arguments-value)
->   - [default_values](#8-default_values---a-list-of-values-which-will-be-used-if-no-values-for-an-argument-have-been-parsed)
+>   - [greedy](#6-greedy---if-this-option-is-set-the-argument-will-consume-all-command-line-values-until-its-upper-nargs-bound-is-reached)
+>   - [choices](#7-choices---a-list-of-valid-argument-values)
+>   - [value actions](#8-value-actions---functions-that-are-called-after-parsing-an-arguments-value)
+>   - [default_values](#9-default_values---a-list-of-values-which-will-be-used-if-no-values-for-an-argument-have-been-parsed)
 >   - [implicit_values](#2-implicit_values---a-list-of-values-which-will-be-set-for-an-argument-if-only-its-flag-but-no-values-are-parsed-from-the-command-line)
 
 You can also add boolean flags:
@@ -343,8 +355,8 @@ Command                                 Result
 
 > [!NOTE]
 >
-> - Both positional and optional arguments have the `bypass_required` option disabled.
-> - The default value of the value parameter of the `bypass_required(bool)` function is `true` for both positional and optional arguments.
+> - Both all arguments have the `bypass_required` option disabled.
+> - The default value of the value parameter of the `argument::bypass_required(bool)` method is `true` for all arguments.
 
 > [!WARNING]
 >
@@ -377,7 +389,9 @@ os << data << std::endl;
 
 <br />
 
-#### 5. `nargs` - Sets the allowed number of values to be parsed for an argument. This can be set as a:
+#### 5. `nargs` - Sets the allowed number of values to be parsed for an argument.
+
+The `nargs` parameter can be set as:
 
 - Specific number:
 
@@ -416,7 +430,49 @@ os << data << std::endl;
 
 <br />
 
-#### 6. `choices` - A list of valid argument values.
+#### 6. `greedy` - If this option is set, the argument will consume ALL command-line values until it's upper nargs bound is reached.
+
+> [!NOTE]
+>
+> - By default the `greedy` option is disabled for all arguments.
+> - The default value of the parameter of the `argument::greedy(bool)` method is true for all arguments.
+
+> [!TIP]
+>
+> - Enabling the `greedy` option for an argument only makes sense for arguments with string-like value types.
+> - If no explicit `nargs` bound is set for a greedy argument, once it starts being parsed, it will consume all remaining command-line arguments.
+
+Consider a simple example:
+
+```cpp
+ap::argument_parser parser;
+parser.program_name("run-script")
+      .default_arguments(ap::default_argument::o_help);
+
+parser.add_positional_argument("script")
+      .help("The name of the script to run");
+parser.add_optional_argument("args")
+      .greedy()
+      .help("Set the execution option");
+
+parser.try_parse_args(argc, argv);
+
+// Application logic here
+std::cout << "Executing: " << parser.value("script") << " " << ap::util::join(parser.values("args")) << std::endl;
+```
+
+Here the program execution should look something like this:
+
+```txt
+> ./run-script remove-comments --args module.py -v --type py
+Executing: remove-comments module.py -v --type py
+```
+
+Notice that even though the `-v` and `--type` command-line arguments have flag prefixes and are not defined in the program, they are not treated as unknown arguments (and therefore no exception is thrown) because the `--args` argument is marked as `greedy` and it consumes these command-line arguments as its values.
+
+<br />
+
+#### 7. `choices` - A list of valid argument values.
 
 ```cpp
 parser.add_optional_argument<char>("method", "m").choices('a', 'b', 'c');
@@ -433,7 +489,7 @@ parser.add_optional_argument<char>("method", "m").choices('a', 'b', 'c');
 
 <br />
 
-#### 7. Value actions - Function performed after parsing an argument's value.
+#### 8. value actions - Functions that are called after parsing an argument's value.
 Actions are represented as functions, which take the argument's value as an argument. The available action types are:
 
 - `observe` actions | `void(const value_type&)` - applied to the parsed value. No value is returned - this action type is used to perform some logic on the parsed value without modifying it.
@@ -478,7 +534,7 @@ Actions are represented as functions, which take the argument's value as an argu
 
 <br />
 
-#### 8. `default_values` - A list of values which will be used if no values for an argument have been parsed
+#### 9. `default_values` - A list of values which will be used if no values for an argument have been parsed
 
 > [!WARNING]
 >
@@ -541,7 +597,7 @@ Command                                 Result
 
 Apart from the common parameters listed above, for optional arguments you can also specify the following parameters:
 
-#### 1. On-flag actions - For optional arguments, apart from value actions, you can specify on-flag actions which are executed immediately after parsing an argument's flag.
+#### 1. on-flag actions - Functions that are called immediately after parsing an argument's flag.
 
 ```cpp
 void print_debug_info() noexcept {

include/ap/argument.hpp

@@ -123,6 +123,11 @@ class argument : public detail::argument_base {
         return not this->_required and this->_bypass_required;
     }
 
+    /// @return `true` if the argument is greedy, `false` otherwise.
+    [[nodiscard]] bool is_greedy() const noexcept override {
+        return this->_greedy;
+    }
+
     // attribute setters
 
     /**
@@ -171,6 +176,19 @@ class argument : public detail::argument_base {
         return *this;
     }
 
+    /**
+     * @brief Set the `greedy` attribute of the argument.
+     * @param g The attribute value.
+     * @return Reference to the argument instance.
+     * @note The method is enabled only if `value_type` is not `none_type`.
+     */
+    argument& greedy(const bool g = true) noexcept
+    requires(not util::c_is_none<value_type>)
+    {
+        this->_greedy = g;
+        return *this;
+    }
+
     /**
      * @brief Set the nargs range for the argument.
      * @param range The attribute value.
@@ -193,8 +211,7 @@ class argument : public detail::argument_base {
     argument& nargs(const count_type n) noexcept
     requires(not util::c_is_none<value_type>)
     {
-        this->_nargs_range = nargs::range(n);
-        return *this;
+        return this->nargs(nargs::range(n));
     }
 
     /**
@@ -207,8 +224,7 @@ class argument : public detail::argument_base {
     argument& nargs(const count_type lower, const count_type upper) noexcept
     requires(not util::c_is_none<value_type>)
     {
-        this->_nargs_range = nargs::range(lower, upper);
-        return *this;
+        return this->nargs(nargs::range(lower, upper));
     }
 
     /**
@@ -671,7 +687,7 @@ class argument : public detail::argument_base {
     // attributes
     const ap::detail::argument_name _name; ///< The argument's name.
     std::optional<std::string> _help_msg; ///< The argument's help message.
-    nargs::range _nargs_range; ///< The argument's nargs range attribute.
+    nargs::range _nargs_range; ///< The argument's nargs range attribute value.
     [[no_unique_address]] value_arg_specific_type<std::vector<std::any>>
         _default_values; ///< The argument's default value list.
     [[no_unique_address]] value_arg_specific_type<optional_specific_type<std::vector<std::any>>>
@@ -683,9 +699,10 @@ class argument : public detail::argument_base {
     [[no_unique_address]] value_arg_specific_type<std::vector<value_action_type>>
         _value_actions; ///< The argument's value actions collection.
 
-    bool _required : 1; ///< The argument's `required` attribute.
-    bool _bypass_required : 1 = false; ///< The argument's `bypass_required` attribute.
-    bool _hidden : 1 = false; ///< The argument's `hidden` attribute.
+    bool _required : 1; ///< The argument's `required` attribute value.
+    bool _bypass_required : 1 = false; ///< The argument's `bypass_required` attribute value.
+    bool _greedy : 1 = false; ///< The argument's `greedy` attribute value.
+    bool _hidden : 1 = false; ///< The argument's `hidden` attribute value.
 
     // parsing result
     [[no_unique_address]] optional_specific_type<std::size_t>