sharg::regex_validator Class Reference

A validator that checks if a matches a regular expression pattern. More...

#include <sharg/validators.hpp>

Inheritance diagram for sharg::regex_validator:

Public Types
using	option_value_type = std::string
	Type of values that are tested by validator.

Public Member Functions
	regex_validator (std::string const &pattern_)
	Constructing from a vector.
void	operator() (option_value_type const &cmp) const
	Tests whether cmp lies inside values.
template<std::ranges::forward_range range_type> requires std::convertible_to<std::ranges::range_reference_t<range_type>, std::string const &>
void	operator() (range_type const &v) const
	Tests whether every entry in list v matches the pattern.
std::string	get_help_page_message () const
	Returns a message that can be appended to the (positional) options help page info.

Private Attributes
std::string	pattern
	The pattern to match.

Detailed Description

A validator that checks if a matches a regular expression pattern.

On construction, the validator must receive a pattern for a regular expression. The pattern variable will be used for constructing a std::regex and the validator will call std::regex_match on the command line argument. Note: A regex_match will only return true if the strings matches the pattern completely (in contrast to regex_search which also matches substrings).

The class than acts as a functor, that throws a sharg::validation_error exception whenever string does not match the pattern.

// SPDX-FileCopyrightText: 2006-2024 Knut Reinert & Freie Universität Berlin
// SPDX-FileCopyrightText: 2016-2024 Knut Reinert & MPI für molekulare Genetik
// SPDX-License-Identifier: CC0-1.0
 
#include <sharg/all.hpp>
 
int main(int argc, char const ** argv)
{
    sharg::parser myparser{"Test", argc, argv}; // initialize
 
    std::string my_string;
    sharg::regex_validator my_validator{"[a-zA-Z]+@[a-zA-Z]+\\.com"};
 
    myparser.add_option(my_string,
                        sharg::config{.short_id = 's',
                                      .long_id = "str",
                                      .description = "Give me a string.",
                                      .validator = my_validator});
 
    // an exception will be thrown if the user specifies a string
    // that is no email address ending on .com
    try
    {
        myparser.parse();
    }
    catch (sharg::parser_error const & ext) // the user did something wrong
    {
        std::cerr << "[PARSER ERROR] " << ext.what() << "\n"; // customize your error message
        return -1;
    }
 
    std::cerr << "email address given by user passed validation: " << my_string << "\n";
    return 0;
}

Remarks

For a complete overview, take a look at Parser

This entity is stable. Since version 1.0.

Constructor & Destructor Documentation

regex_validator()

sharg::regex_validator::regex_validator ( std::string const & pattern_ )

inline

Constructing from a vector.

Parameters

[in]

pattern_

The pattern to match.

This entity is stable. Since version 1.0.

Member Function Documentation

get_help_page_message()

std::string sharg::regex_validator::get_help_page_message ( ) const

inline

Returns a message that can be appended to the (positional) options help page info.

This entity is stable. Since version 1.0.

operator()() [1/2]

void sharg::regex_validator::operator() ( option_value_type const & cmp ) const

inline

Tests whether cmp lies inside values.

Parameters

[in]

cmp

The value to validate.

Exceptions

sharg::validation_error

This entity is stable. Since version 1.0.

operator()() [2/2]

template<std::ranges::forward_range range_type>
requires std::convertible_to<std::ranges::range_reference_t<range_type>, std::string const &>

void sharg::regex_validator::operator() ( range_type const & v ) const

inline

Tests whether every entry in list v matches the pattern.

Template Parameters

range_type

The type of range to check; must model std::ranges::forward_range and the value type must be convertible to std::string.

Parameters

v	The input range to iterate over and check every element.

Exceptions

sharg::validation_error

This entity is stable. Since version 1.0.

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The documentation for this class was generated from the following file:

• validators.hpp