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#pragma once
#include <iostream>
#include <map>
#include <memory>
#include "util.hh"
namespace nix {
MakeError(UsageError, Error);
enum HashType : char;
class Args
{
public:
/* Parse the command line, throwing a UsageError if something goes
wrong. */
void parseCmdline(const Strings & cmdline);
virtual void printHelp(const string & programName, std::ostream & out);
virtual std::string description() { return ""; }
protected:
/* Flags. */
struct Flag
{
typedef std::shared_ptr<Flag> ptr;
std::string longName;
char shortName = 0;
std::string description;
Strings labels;
size_t arity = 0;
std::function<void(Strings)> handler;
std::string category;
};
std::map<std::string, Flag::ptr> longFlags;
std::map<char, Flag::ptr> shortFlags;
virtual bool processFlag(Strings::iterator & pos, Strings::iterator end);
virtual void printFlags(std::ostream & out);
/* Positional arguments. */
struct ExpectedArg
{
std::string label;
size_t arity; // 0 = any
std::function<void(Strings)> handler;
};
std::list<ExpectedArg> expectedArgs;
virtual bool processArgs(const Strings & args, bool finish);
std::set<std::string> hiddenCategories;
public:
class FlagMaker
{
Args & args;
Flag::ptr flag;
friend class Args;
FlagMaker(Args & args) : args(args), flag(std::make_shared<Flag>()) { };
public:
~FlagMaker();
FlagMaker & longName(const std::string & s) { flag->longName = s; return *this; };
FlagMaker & shortName(char s) { flag->shortName = s; return *this; };
FlagMaker & description(const std::string & s) { flag->description = s; return *this; };
FlagMaker & labels(const Strings & ls) { flag->labels = ls; return *this; };
FlagMaker & arity(size_t arity) { flag->arity = arity; return *this; };
FlagMaker & handler(std::function<void(Strings)> handler) { flag->handler = handler; return *this; };
FlagMaker & category(const std::string & s) { flag->category = s; return *this; };
};
FlagMaker mkFlag();
/* Helper functions for constructing flags / positional
arguments. */
void mkFlag(char shortName, const std::string & longName,
const std::string & description, std::function<void()> fun)
{
mkFlag()
.shortName(shortName)
.longName(longName)
.description(description)
.handler(std::bind(fun));
}
void mkFlag1(char shortName, const std::string & longName,
const std::string & label, const std::string & description,
std::function<void(std::string)> fun)
{
mkFlag()
.shortName(shortName)
.longName(longName)
.labels({label})
.description(description)
.arity(1)
.handler([=](Strings ss) { fun(ss.front()); });
}
void mkFlag(char shortName, const std::string & name,
const std::string & description, bool * dest)
{
mkFlag(shortName, name, description, dest, true);
}
void mkFlag(char shortName, const std::string & longName,
const std::string & label, const std::string & description,
string * dest)
{
mkFlag1(shortName, longName, label, description, [=](std::string s) {
*dest = s;
});
}
void mkHashTypeFlag(const std::string & name, HashType * ht);
template<class T>
void mkFlag(char shortName, const std::string & longName, const std::string & description,
T * dest, const T & value)
{
mkFlag()
.shortName(shortName)
.longName(longName)
.description(description)
.handler([=](Strings ss) { *dest = value; });
}
template<class I>
void mkIntFlag(char shortName, const std::string & longName,
const std::string & description, I * dest)
{
mkFlag<I>(shortName, longName, description, [=](I n) {
*dest = n;
});
}
template<class I>
void mkFlag(char shortName, const std::string & longName,
const std::string & description, std::function<void(I)> fun)
{
mkFlag()
.shortName(shortName)
.longName(longName)
.labels({"N"})
.description(description)
.arity(1)
.handler([=](Strings ss) {
I n;
if (!string2Int(ss.front(), n))
throw UsageError(format("flag ‘--%1%’ requires a integer argument") % longName);
fun(n);
});
}
/* Expect a string argument. */
void expectArg(const std::string & label, string * dest)
{
expectedArgs.push_back(ExpectedArg{label, 1, [=](Strings ss) {
*dest = ss.front();
}});
}
/* Expect 0 or more arguments. */
void expectArgs(const std::string & label, Strings * dest)
{
expectedArgs.push_back(ExpectedArg{label, 0, [=](Strings ss) {
*dest = ss;
}});
}
friend class MultiCommand;
};
Strings argvToStrings(int argc, char * * argv);
/* Helper function for rendering argument labels. */
std::string renderLabels(const Strings & labels);
/* Helper function for printing 2-column tables. */
typedef std::vector<std::pair<std::string, std::string>> Table2;
void printTable(std::ostream & out, const Table2 & table);
}
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