.. _program_listing_file_lib_options_validation.hpp:

Program Listing for File validation.hpp
=======================================

|exhale_lsh| :ref:`Return to documentation for file <file_lib_options_validation.hpp>` (``lib/options/validation.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // ---------------------------------------------------------------------
   // This file is part of falcon-core.
   //
   // Copyright (C) 2015, 2016, 2017 Neuro-Electronics Research Flanders
   //
   // Falcon-server is free software: you can redistribute it and/or modify
   // it under the terms of the GNU General Public License as published by
   // the Free Software Foundation, either version 3 of the License, or
   // (at your option) any later version.
   //
   // Falcon-server is distributed in the hope that it will be useful,
   // but WITHOUT ANY WARRANTY; without even the implied warranty of
   // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   // GNU General Public License for more details.
   //
   // You should have received a copy of the GNU General Public License
   // along with falcon-core. If not, see <http://www.gnu.org/licenses/>.
   // ---------------------------------------------------------------------
   #pragma once
   
   #include <limits>
   #include <regex>
   #include <stdexcept>
   #include <string>
   #include <vector>
   #include <algorithm>
   
   #include "units/units.hpp"
   
   #include "../utilities/filesystem.hpp"
   
   namespace options {
   
   class ValidationError : public std::runtime_error {
    public:
     ValidationError(std::string msg) : std::runtime_error(msg) {}
   };
   
   class ConversionError : public std::runtime_error {
    public:
     ConversionError(std::string msg) : std::runtime_error(msg) {}
   };
   
   template <typename T> using ValidatorFunc = std::function<T(const T &)>;
   
   template <typename T>
   ValidatorFunc<T> compose(ValidatorFunc<T> f, ValidatorFunc<T> g) {
     return [f, g](T x) { return f(g(x)); };
   }
   
   template <typename T> class validator {
    public:
     friend auto operator+(const ValidatorFunc<T> &lhs,
                           const ValidatorFunc<T> &rhs) {
       return compose<T>(rhs, lhs);
     }
   };
   
   template <typename T> class inrange : public validator<T> {
     static_assert(std::is_arithmetic<T>::value,
                   "inrange validator only supports numerical types.");
   
    public:
     using value_type = T;
   
    public:
     inrange(T min, T max) : min_(min), max_(max) {}
   
     T operator()(const T &x) const {
       if (x < min_ || x > max_) {
         throw ValidationError("Value out of range.");
       }
       return x;
     }
   
    protected:
     T min_;
     T max_;
   };
   
   template <typename T> class clamped : public validator<T> {
     static_assert(std::is_arithmetic<T>::value,
                   "clamped validator only supports numerical types.");
   
    public:
     using value_type = T;
   
    public:
     clamped(T min, T max) : min_(min), max_(max) {}
   
     T operator()(const T &x) const {
       T y = x;
       std::clamp(y, min_, max_);
       return y;
     }
   
    protected:
     T min_;
     T max_;
   };
   
   template <typename T> class squared : public validator<T> {
     static_assert(std::is_arithmetic<T>::value,
                   "squared validator only supports numerical types.");
   
    public:
     T operator()(const T &x) const { return x * x; }
   };
   
   template <typename T> class multiplied : public validator<T> {
     static_assert(std::is_arithmetic<T>::value,
                   "multiplier validator only supports numerical types.");
   
    public:
     multiplied(T multiplier) : multiplier_(multiplier) {}
   
     T operator()(const T &x) const { return multiplier_ * x; }
   
    protected:
     T multiplier_;
   };
   
   class invert : public validator<bool> {
    public:
     bool operator()(const bool &x) const { return !x; }
   };
   
   template <typename T> class zeroismax : public validator<T> {
    public:
     T operator()(const T &x) {
       if (x == 0) {
         return std::numeric_limits<T>::max();
       } else {
         return x;
       }
     }
   };
   
   template <typename T> class notempty : public validator<T> {
    public:
     T operator()(const T &x) {
       if (x.size() == 0) {
         throw ValidationError("Container or value cannot be empty.");
       }
       return x;
     }
   };
   
   template <typename T> class each : public validator<std::vector<T>> {
    public:
     each(ValidatorFunc<T> validator) : validator_(validator) {}
   
     std::vector<T> operator()(const std::vector<T> &x) {
       std::vector<T> y = x;
       std::transform(x.begin(), x.end(), y.begin(), validator_);
       return x;
     }
   
    protected:
     ValidatorFunc<T> validator_;
   };
   
   template <typename T> class positive : public validator<T> {
    public:
     positive(bool strict = false) : strict_(strict) {}
   
     T operator()(const T &x) const {
       if ((strict_ && x <= 0) || x < 0) {
         if (strict_) {
           throw ValidationError("Value cannot be negative or zero.");
         } else {
           throw ValidationError("Value cannot be negative.");
         }
       }
       return x;
     }
   
    protected:
     bool strict_;
   };
   
   class isfile : public validator<std::string> {
    public:
     isfile(bool exists = false) : exists_(exists) {}
   
     std::string operator()(const std::string &x) const {
       return parse_file(x, exists_).string();
     }
   
    protected:
     bool exists_;
   };
   
   class isdir : public validator<std::string> {
    public:
     isdir(bool exists = true, bool create = false)
         : exists_(exists), create_(create) {}
   
     std::string operator()(const std::string &x) const {
       return parse_directory(x, exists_, create_).string();
     }
   
    protected:
     bool exists_;
     bool create_;
   };
   
   }  // namespace options