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#pragma once
#include <algorithm>
#include <sstream>
#include <limits>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <cassert>
namespace argh
{
// Terminology:
// A command line is composed of 2 types of args:
// 1. Positional args, i.e. free standing values
// 2. Options: args beginning with '-'. We identify two kinds:
// 2.1: Flags: boolean options => (exist ? true : false)
// 2.2: Parameters: a name followed by a non-option value
#if !defined(__GNUC__) || (__GNUC__ >= 5)
using string_stream = std::istringstream;
#else
// Until GCC 5, istringstream did not have a move constructor.
// stringstream_proxy is used instead, as a workaround.
class stringstream_proxy
{
public:
stringstream_proxy() = default;
// Construct with a value.
stringstream_proxy(std::string const& value) :
stream_(value)
{}
// Copy constructor.
stringstream_proxy(const stringstream_proxy& other) :
stream_(other.stream_.str())
{
stream_.setstate(other.stream_.rdstate());
}
void setstate(std::ios_base::iostate state) { stream_.setstate(state); }
// Stream out the value of the parameter.
// If the conversion was not possible, the stream will enter the fail state,
// and operator bool will return false.
template<typename T>
stringstream_proxy& operator >> (T& thing)
{
stream_ >> thing;
return *this;
}
// Get the string value.
std::string str() const { return stream_.str(); }
std::stringbuf* rdbuf() const { return stream_.rdbuf(); }
// Check the state of the stream.
// False when the most recent stream operation failed
explicit operator bool() const { return !!stream_; }
~stringstream_proxy() = default;
private:
std::istringstream stream_;
};
using string_stream = stringstream_proxy;
#endif
class multimap_iteration_wrapper
{
public:
using container_t = std::multimap<std::string, std::string>;
using iterator_t = container_t::const_iterator;
using difference_t = container_t::difference_type;
explicit multimap_iteration_wrapper(const iterator_t& lb, const iterator_t& ub)
: lb_(lb)
, ub_(ub)
{}
iterator_t begin() const { return lb_; }
iterator_t end() const { return ub_; }
difference_t size() const { return std::distance(lb_, ub_); }
private:
iterator_t lb_;
iterator_t ub_;
};
class parser
{
public:
enum Mode { PREFER_FLAG_FOR_UNREG_OPTION = 1 << 0,
PREFER_PARAM_FOR_UNREG_OPTION = 1 << 1,
NO_SPLIT_ON_EQUALSIGN = 1 << 2,
SINGLE_DASH_IS_MULTIFLAG = 1 << 3,
};
parser() = default;
parser(std::initializer_list<char const* const> pre_reg_names)
{ add_params(pre_reg_names); }
parser(const char* const argv[], int mode = PREFER_FLAG_FOR_UNREG_OPTION)
{ parse(argv, mode); }
parser(int argc, const char* const argv[], int mode = PREFER_FLAG_FOR_UNREG_OPTION)
{ parse(argc, argv, mode); }
void add_param(std::string const& name);
void add_params(std::string const& name);
void add_param(std::initializer_list<char const* const> init_list);
void add_params(std::initializer_list<char const* const> init_list);
void parse(const char* const argv[], int mode = PREFER_FLAG_FOR_UNREG_OPTION);
void parse(int argc, const char* const argv[], int mode = PREFER_FLAG_FOR_UNREG_OPTION);
std::multiset<std::string> const& flags() const { return flags_; }
std::multimap<std::string, std::string> const& params() const { return params_; }
multimap_iteration_wrapper params(std::string const& name) const;
std::vector<std::string> const& pos_args() const { return pos_args_; }
// begin() and end() for using range-for over positional args.
std::vector<std::string>::const_iterator begin() const { return pos_args_.cbegin(); }
std::vector<std::string>::const_iterator end() const { return pos_args_.cend(); }
size_t size() const { return pos_args_.size(); }
//////////////////////////////////////////////////////////////////////////
// Accessors
// flag (boolean) accessors: return true if the flag appeared, otherwise false.
bool operator[](std::string const& name) const;
// multiple flag (boolean) accessors: return true if at least one of the flag appeared, otherwise false.
bool operator[](std::initializer_list<char const* const> init_list) const;
// returns positional arg string by order. Like argv[] but without the options
std::string const& operator[](size_t ind) const;
// returns a std::istream that can be used to convert a positional arg to a typed value.
string_stream operator()(size_t ind) const;
// same as above, but with a default value in case the arg is missing (index out of range).
template<typename T>
string_stream operator()(size_t ind, T&& def_val) const;
// parameter accessors, give a name get an std::istream that can be used to convert to a typed value.
// call .str() on result to get as string
string_stream operator()(std::string const& name) const;
// accessor for a parameter with multiple names, give a list of names, get an std::istream that can be used to convert to a typed value.
// call .str() on result to get as string
// returns the first value in the list to be found.
string_stream operator()(std::initializer_list<char const* const> init_list) const;
// same as above, but with a default value in case the param was missing.
// Non-string def_val types must have an operator<<() (output stream operator)
// If T only has an input stream operator, pass the string version of the type as in "3" instead of 3.
template<typename T>
string_stream operator()(std::string const& name, T&& def_val) const;
// same as above but for a list of names. returns the first value to be found.
template<typename T>
string_stream operator()(std::initializer_list<char const* const> init_list, T&& def_val) const;
private:
string_stream bad_stream() const;
std::string trim_leading_dashes(std::string const& name) const;
bool is_number(std::string const& arg) const;
bool is_option(std::string const& arg) const;
bool got_flag(std::string const& name) const;
bool is_param(std::string const& name) const;
private:
std::vector<std::string> args_;
std::multimap<std::string, std::string> params_;
std::vector<std::string> pos_args_;
std::multiset<std::string> flags_;
std::set<std::string> registeredParams_;
std::string empty_;
};
//////////////////////////////////////////////////////////////////////////
inline void parser::parse(const char * const argv[], int mode)
{
int argc = 0;
for (auto argvp = argv; *argvp; ++argc, ++argvp);
parse(argc, argv, mode);
}
//////////////////////////////////////////////////////////////////////////
inline void parser::parse(int argc, const char* const argv[], int mode /*= PREFER_FLAG_FOR_UNREG_OPTION*/)
{
// clear out possible previous parsing remnants
flags_.clear();
params_.clear();
pos_args_.clear();
// convert to strings
args_.resize(static_cast<decltype(args_)::size_type>(argc));
std::transform(argv, argv + argc, args_.begin(), [](const char* const arg) { return arg; });
// parse line
for (auto i = 0u; i < args_.size(); ++i)
{
if (!is_option(args_[i]))
{
pos_args_.emplace_back(args_[i]);
continue;
}
auto name = trim_leading_dashes(args_[i]);
if (!(mode & NO_SPLIT_ON_EQUALSIGN))
{
auto equalPos = name.find('=');
if (equalPos != std::string::npos)
{
params_.insert({ name.substr(0, equalPos), name.substr(equalPos + 1) });
continue;
}
}
// if the option is unregistered and should be a multi-flag
if (1 == (args_[i].size() - name.size()) && // single dash
argh::parser::SINGLE_DASH_IS_MULTIFLAG & mode && // multi-flag mode
!is_param(name)) // unregistered
{
std::string keep_param;
if (!name.empty() && is_param(std::string(1ul, name.back()))) // last char is param
{
keep_param += name.back();
name.resize(name.size() - 1);
}
for (auto const& c : name)
{
flags_.emplace(std::string{ c });
}
if (!keep_param.empty())
{
name = keep_param;
}
else
{
continue; // do not consider other options for this arg
}
}
// any potential option will get as its value the next arg, unless that arg is an option too
// in that case it will be determined a flag.
if (i == args_.size() - 1 || is_option(args_[i + 1]))
{
flags_.emplace(name);
continue;
}
// if 'name' is a pre-registered option, then the next arg cannot be a free parameter to it is skipped
// otherwise we have 2 modes:
// PREFER_FLAG_FOR_UNREG_OPTION: a non-registered 'name' is determined a flag.
// The following value (the next arg) will be a free parameter.
//
// PREFER_PARAM_FOR_UNREG_OPTION: a non-registered 'name' is determined a parameter, the next arg
// will be the value of that option.
assert(!(mode & argh::parser::PREFER_FLAG_FOR_UNREG_OPTION)
|| !(mode & argh::parser::PREFER_PARAM_FOR_UNREG_OPTION));
bool preferParam = mode & argh::parser::PREFER_PARAM_FOR_UNREG_OPTION;
if (is_param(name) || preferParam)
{
params_.insert({ name, args_[i + 1] });
++i; // skip next value, it is not a free parameter
continue;
}
else
{
flags_.emplace(name);
}
}
}
//////////////////////////////////////////////////////////////////////////
inline string_stream parser::bad_stream() const
{
string_stream bad;
bad.setstate(std::ios_base::failbit);
return bad;
}
//////////////////////////////////////////////////////////////////////////
inline bool parser::is_number(std::string const& arg) const
{
// inefficient but simple way to determine if a string is a number (which can start with a '-')
std::istringstream istr(arg);
double number;
istr >> number;
return !(istr.fail() || istr.bad());
}
//////////////////////////////////////////////////////////////////////////
inline bool parser::is_option(std::string const& arg) const
{
assert(0 != arg.size());
if (is_number(arg))
return false;
return '-' == arg[0];
}
//////////////////////////////////////////////////////////////////////////
inline std::string parser::trim_leading_dashes(std::string const& name) const
{
auto pos = name.find_first_not_of('-');
return std::string::npos != pos ? name.substr(pos) : name;
}
//////////////////////////////////////////////////////////////////////////
inline bool argh::parser::got_flag(std::string const& name) const
{
return flags_.end() != flags_.find(trim_leading_dashes(name));
}
//////////////////////////////////////////////////////////////////////////
inline bool argh::parser::is_param(std::string const& name) const
{
return registeredParams_.count(name);
}
//////////////////////////////////////////////////////////////////////////
inline bool parser::operator[](std::string const& name) const
{
return got_flag(name);
}
//////////////////////////////////////////////////////////////////////////
inline bool parser::operator[](std::initializer_list<char const* const> init_list) const
{
return std::any_of(init_list.begin(), init_list.end(), [&](char const* const name) { return got_flag(name); });
}
//////////////////////////////////////////////////////////////////////////
inline std::string const& parser::operator[](size_t ind) const
{
if (ind < pos_args_.size())
return pos_args_[ind];
return empty_;
}
//////////////////////////////////////////////////////////////////////////
inline string_stream parser::operator()(std::string const& name) const
{
auto optIt = params_.find(trim_leading_dashes(name));
if (params_.end() != optIt)
return string_stream(optIt->second);
return bad_stream();
}
//////////////////////////////////////////////////////////////////////////
inline string_stream parser::operator()(std::initializer_list<char const* const> init_list) const
{
for (auto& name : init_list)
{
auto optIt = params_.find(trim_leading_dashes(name));
if (params_.end() != optIt)
return string_stream(optIt->second);
}
return bad_stream();
}
//////////////////////////////////////////////////////////////////////////
template<typename T>
string_stream parser::operator()(std::string const& name, T&& def_val) const
{
auto optIt = params_.find(trim_leading_dashes(name));
if (params_.end() != optIt)
return string_stream(optIt->second);
std::ostringstream ostr;
ostr.precision(std::numeric_limits<long double>::max_digits10);
ostr << def_val;
return string_stream(ostr.str()); // use default
}
//////////////////////////////////////////////////////////////////////////
// same as above but for a list of names. returns the first value to be found.
template<typename T>
string_stream parser::operator()(std::initializer_list<char const* const> init_list, T&& def_val) const
{
for (auto& name : init_list)
{
auto optIt = params_.find(trim_leading_dashes(name));
if (params_.end() != optIt)
return string_stream(optIt->second);
}
std::ostringstream ostr;
ostr.precision(std::numeric_limits<long double>::max_digits10);
ostr << def_val;
return string_stream(ostr.str()); // use default
}
//////////////////////////////////////////////////////////////////////////
inline string_stream parser::operator()(size_t ind) const
{
if (pos_args_.size() <= ind)
return bad_stream();
return string_stream(pos_args_[ind]);
}
//////////////////////////////////////////////////////////////////////////
template<typename T>
string_stream parser::operator()(size_t ind, T&& def_val) const
{
if (pos_args_.size() <= ind)
{
std::ostringstream ostr;
ostr.precision(std::numeric_limits<long double>::max_digits10);
ostr << def_val;
return string_stream(ostr.str());
}
return string_stream(pos_args_[ind]);
}
//////////////////////////////////////////////////////////////////////////
inline void parser::add_param(std::string const& name)
{
registeredParams_.insert(trim_leading_dashes(name));
}
//////////////////////////////////////////////////////////////////////////
inline void parser::add_param(std::initializer_list<const char *const> init_list)
{
parser::add_params(init_list);
}
//////////////////////////////////////////////////////////////////////////
inline void parser::add_params(std::initializer_list<char const* const> init_list)
{
for (auto& name : init_list)
registeredParams_.insert(trim_leading_dashes(name));
}
//////////////////////////////////////////////////////////////////////////
inline void parser::add_params(const std::string &name)
{
parser::add_param(name);
}
//////////////////////////////////////////////////////////////////////////
inline multimap_iteration_wrapper parser::params(std::string const& name) const
{
auto trimmed_name = trim_leading_dashes(name);
return multimap_iteration_wrapper(params_.lower_bound(trimmed_name), params_.upper_bound(trimmed_name));
}
}