mapnik/include/mapnik/value.hpp
artemp 18554ec0b1 remove static_visitor usage and rely on automatic result type deduction
(NOTE: expression_evaluator requires  ```using result_type = T1;``` )

Conflicts:
	src/image.cpp
2015-01-07 11:39:06 +01:00

978 lines
21 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2014 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
#ifndef MAPNIK_VALUE_HPP
#define MAPNIK_VALUE_HPP
// mapnik
#include <mapnik/value_types.hpp>
#include <mapnik/value_hash.hpp>
#include <mapnik/util/conversions.hpp>
#include <mapnik/util/variant.hpp>
// stl
#include <string>
#include <cmath>
#include <memory>
#include <iosfwd>
#include <cstddef>
#include <new>
// icu
#include <unicode/unistr.h>
#include <unicode/ustring.h>
namespace mapnik {
inline void to_utf8(mapnik::value_unicode_string const& input, std::string & target)
{
if (input.isEmpty()) return;
const int BUF_SIZE = 256;
char buf [BUF_SIZE];
int len;
UErrorCode err = U_ZERO_ERROR;
u_strToUTF8(buf, BUF_SIZE, &len, input.getBuffer(), input.length(), &err);
if (err == U_BUFFER_OVERFLOW_ERROR || err == U_STRING_NOT_TERMINATED_WARNING )
{
const std::unique_ptr<char[]> buf_ptr(new char [len+1]);
err = U_ZERO_ERROR;
u_strToUTF8(buf_ptr.get() , len + 1, &len, input.getBuffer(), input.length(), &err);
target.assign(buf_ptr.get() , static_cast<std::size_t>(len));
}
else
{
target.assign(buf, static_cast<std::size_t>(len));
}
}
using value_base = util::variant<value_null, value_bool, value_integer,value_double, value_unicode_string>;
namespace impl {
struct equals
{
bool operator() (value_integer lhs, value_double rhs) const
{
return lhs == rhs;
}
bool operator() (value_bool lhs, value_double rhs) const
{
return lhs == rhs;
}
bool operator() (value_double lhs, value_integer rhs) const
{
return lhs == rhs;
}
bool operator() (value_bool lhs, value_integer rhs) const
{
return lhs == rhs;
}
bool operator() (value_integer lhs, value_bool rhs) const
{
return lhs == rhs;
}
bool operator() (value_double lhs, value_bool rhs) const
{
return lhs == rhs;
}
bool operator() (value_unicode_string const& lhs,
value_unicode_string const& rhs) const
{
return (lhs == rhs) ? true: false;
}
template <typename T>
bool operator() (T lhs, T rhs) const
{
return lhs == rhs;
}
template <typename T, typename U>
bool operator() (T const&, U const&) const
{
return false;
}
};
struct not_equals
{
template <typename T, typename U>
bool operator() (const T &, const U &) const
{
return true;
}
template <typename T>
bool operator() (T lhs, T rhs) const
{
return lhs != rhs;
}
bool operator() (value_integer lhs, value_double rhs) const
{
return lhs != rhs;
}
bool operator() (value_bool lhs, value_double rhs) const
{
return lhs != rhs;
}
bool operator() (value_double lhs, value_integer rhs) const
{
return lhs != rhs;
}
bool operator() (value_bool lhs, value_integer rhs) const
{
return lhs != rhs;
}
bool operator() (value_integer lhs, value_bool rhs) const
{
return lhs != rhs;
}
bool operator() (value_double lhs, value_bool rhs) const
{
return lhs != rhs;
}
bool operator() (value_unicode_string const& lhs,
value_unicode_string const& rhs) const
{
return (lhs != rhs)? true : false;
}
// back compatibility shim to equate empty string with null for != test
// https://github.com/mapnik/mapnik/issues/1859
// TODO - consider removing entire specialization at Mapnik 3.x
bool operator() (value_null, value_unicode_string const& rhs) const
{
if (rhs.isEmpty()) return false;
return true;
}
};
struct greater_than
{
template <typename T, typename U>
bool operator()(const T &, const U &) const
{
return false;
}
template <typename T>
bool operator()(T lhs, T rhs) const
{
return lhs > rhs;
}
bool operator() (value_integer lhs, value_double rhs) const
{
return lhs > rhs;
}
bool operator() (value_double lhs, value_integer rhs) const
{
return lhs > rhs;
}
bool operator() (value_unicode_string const& lhs, value_unicode_string const& rhs) const
{
return (lhs > rhs) ? true : false ;
}
bool operator() (value_null, value_null) const
{
return false;
}
};
struct greater_or_equal
{
template <typename T, typename U>
bool operator()(const T &, const U &) const
{
return false;
}
template <typename T>
bool operator() (T lhs, T rhs) const
{
return lhs >= rhs;
}
bool operator() (value_integer lhs, value_double rhs) const
{
return lhs >= rhs;
}
bool operator() (value_double lhs, value_integer rhs) const
{
return lhs >= rhs;
}
bool operator() (value_unicode_string const& lhs, value_unicode_string const& rhs) const
{
return ( lhs >= rhs ) ? true : false ;
}
bool operator() (value_null, value_null) const
{
return false;
}
};
struct less_than
{
template <typename T, typename U>
bool operator()(const T &, const U &) const
{
return false;
}
template <typename T>
bool operator()(T lhs, T rhs) const
{
return lhs < rhs;
}
bool operator() (value_integer lhs, value_double rhs) const
{
return lhs < rhs;
}
bool operator() (value_double lhs, value_integer rhs) const
{
return lhs < rhs;
}
bool operator()(value_unicode_string const& lhs,
value_unicode_string const& rhs ) const
{
return (lhs < rhs) ? true : false ;
}
bool operator() (value_null, value_null) const
{
return false;
}
};
struct less_or_equal
{
template <typename T, typename U>
bool operator()(const T &, const U &) const
{
return false;
}
template <typename T>
bool operator()(T lhs, T rhs) const
{
return lhs <= rhs;
}
bool operator() (value_integer lhs, value_double rhs) const
{
return lhs <= rhs;
}
bool operator() (value_double lhs, value_integer rhs) const
{
return lhs <= rhs;
}
bool operator()(value_unicode_string const& lhs,
value_unicode_string const& rhs ) const
{
return (lhs <= rhs) ? true : false ;
}
bool operator() (value_null, value_null) const
{
return false;
}
};
template <typename V>
struct add
{
using value_type = V;
value_type operator() (value_unicode_string const& lhs ,
value_unicode_string const& rhs ) const
{
return lhs + rhs;
}
value_type operator() (value_double lhs, value_integer rhs) const
{
return lhs + rhs;
}
value_type operator() (value_integer lhs, value_double rhs) const
{
return lhs + rhs;
}
value_type operator() (value_unicode_string const& lhs, value_null) const
{
return lhs;
}
value_type operator() (value_null, value_unicode_string const& rhs) const
{
return rhs;
}
template <typename R>
value_type operator() (value_unicode_string const& lhs, R const& rhs) const
{
std::string val;
if (util::to_string(val,rhs))
return lhs + value_unicode_string(val.c_str());
return lhs;
}
template <typename L>
value_type operator() (L const& lhs , value_unicode_string const& rhs) const
{
std::string val;
if (util::to_string(val,lhs))
return value_unicode_string(val.c_str()) + rhs;
return rhs;
}
template <typename T>
value_type operator() (T lhs, T rhs) const
{
return lhs + rhs ;
}
template <typename T1, typename T2>
value_type operator() (T1 const& lhs, T2 const&) const
{
return lhs;
}
value_type operator() (value_bool lhs, value_bool rhs) const
{
return value_integer(lhs + rhs);
}
};
template <typename V>
struct sub
{
using value_type = V;
template <typename T1, typename T2>
value_type operator() (T1 const& lhs, T2 const&) const
{
return lhs;
}
template <typename T>
value_type operator() (T lhs, T rhs) const
{
return lhs - rhs ;
}
value_type operator() (value_unicode_string const&,
value_unicode_string const&) const
{
return value_type();
}
value_type operator() (value_double lhs, value_integer rhs) const
{
return lhs - rhs;
}
value_type operator() (value_integer lhs, value_double rhs) const
{
return lhs - rhs;
}
value_type operator() (value_bool lhs, value_bool rhs) const
{
return value_integer(lhs - rhs);
}
};
template <typename V>
struct mult
{
using value_type = V;
template <typename T1, typename T2>
value_type operator() (T1 const& lhs , T2 const& ) const
{
return lhs;
}
template <typename T>
value_type operator() (T lhs, T rhs) const
{
return lhs * rhs;
}
value_type operator() (value_unicode_string const&,
value_unicode_string const&) const
{
return value_type();
}
value_type operator() (value_double lhs, value_integer rhs) const
{
return lhs * rhs;
}
value_type operator() (value_integer lhs, value_double rhs) const
{
return lhs * rhs;
}
value_type operator() (value_bool, value_bool) const
{
return value_integer(0);
}
};
template <typename V>
struct div
{
using value_type = V;
template <typename T1, typename T2>
value_type operator() (T1 const& lhs, T2 const&) const
{
return lhs;
}
template <typename T>
value_type operator() (T lhs, T rhs) const
{
if (rhs == 0) return value_type();
return lhs / rhs;
}
value_type operator() (value_bool, value_bool) const
{
return false;
}
value_type operator() (value_unicode_string const&,
value_unicode_string const&) const
{
return value_type();
}
value_type operator() (value_double lhs, value_integer rhs) const
{
if (rhs == 0) return value_type();
return lhs / rhs;
}
value_type operator() (value_integer lhs, value_double rhs) const
{
if (rhs == 0) return value_type();
return lhs / rhs;
}
};
template <typename V>
struct mod
{
using value_type = V;
template <typename T1, typename T2>
value_type operator() (T1 const& lhs, T2 const&) const
{
return lhs;
}
template <typename T>
value_type operator() (T lhs, T rhs) const
{
return lhs % rhs;
}
value_type operator() (value_unicode_string const&,
value_unicode_string const&) const
{
return value_type();
}
value_type operator() (value_bool,
value_bool) const
{
return false;
}
value_type operator() (value_double lhs, value_integer rhs) const
{
return std::fmod(lhs, static_cast<value_double>(rhs));
}
value_type operator() (value_integer lhs, value_double rhs) const
{
return std::fmod(static_cast<value_double>(lhs), rhs);
}
value_type operator() (value_double lhs, value_double rhs) const
{
return std::fmod(lhs, rhs);
}
};
template <typename V>
struct negate
{
using value_type = V;
template <typename T>
value_type operator() (T val) const
{
return -val;
}
value_type operator() (value_null val) const
{
return val;
}
value_type operator() (value_bool val) const
{
return val ? value_integer(-1) : value_integer(0);
}
value_type operator() (value_unicode_string const&) const
{
return value_type();
}
};
// converters
template <typename T>
struct convert {};
template <>
struct convert<value_bool>
{
value_bool operator() (value_bool val) const
{
return val;
}
value_bool operator() (value_unicode_string const& ustr) const
{
return !ustr.isEmpty();
}
value_bool operator() (value_null const&) const
{
return false;
}
template <typename T>
value_bool operator() (T val) const
{
return val > 0 ? true : false;
}
};
template <>
struct convert<value_double>
{
value_double operator() (value_double val) const
{
return val;
}
value_double operator() (value_integer val) const
{
return static_cast<value_double>(val);
}
value_double operator() (value_bool val) const
{
return static_cast<value_double>(val);
}
value_double operator() (std::string const& val) const
{
value_double result;
if (util::string2double(val,result))
return result;
return 0;
}
value_double operator() (value_unicode_string const& val) const
{
std::string utf8;
to_utf8(val,utf8);
return operator()(utf8);
}
value_double operator() (value_null const&) const
{
return 0.0;
}
};
template <>
struct convert<value_integer>
{
value_integer operator() (value_integer val) const
{
return val;
}
value_integer operator() (value_double val) const
{
return static_cast<value_integer>(rint(val));
}
value_integer operator() (value_bool val) const
{
return static_cast<value_integer>(val);
}
value_integer operator() (std::string const& val) const
{
value_integer result;
if (util::string2int(val,result))
return result;
return value_integer(0);
}
value_integer operator() (value_unicode_string const& val) const
{
std::string utf8;
to_utf8(val,utf8);
return operator()(utf8);
}
value_integer operator() (value_null const&) const
{
return value_integer(0);
}
};
template <>
struct convert<std::string>
{
template <typename T>
std::string operator() (T val) const
{
std::string str;
util::to_string(str, val);
return str;
}
// specializations
std::string operator() (value_unicode_string const& val) const
{
std::string utf8;
to_utf8(val,utf8);
return utf8;
}
std::string operator() (value_double val) const
{
std::string str;
util::to_string(str, val); // TODO set precision(16)
return str;
}
std::string operator() (value_null const&) const
{
return "";
}
};
struct to_unicode
{
template <typename T>
value_unicode_string operator() (T val) const
{
std::string str;
util::to_string(str,val);
return value_unicode_string(str.c_str());
}
// specializations
value_unicode_string const& operator() (value_unicode_string const& val) const
{
return val;
}
value_unicode_string operator() (value_double val) const
{
std::string str;
util::to_string(str,val);
return value_unicode_string(str.c_str());
}
value_unicode_string operator() (value_null const&) const
{
return value_unicode_string("");
}
};
struct to_expression_string
{
explicit to_expression_string(char quote = '\'')
: quote_(quote) {}
std::string operator() (value_unicode_string const& val) const
{
std::string utf8;
to_utf8(val,utf8);
return quote_ + utf8 + quote_;
}
std::string operator() (value_integer val) const
{
std::string output;
util::to_string(output,val);
return output;
}
std::string operator() (value_double val) const
{
std::string output;
util::to_string(output,val); // TODO precision(16)
return output;
}
std::string operator() (value_bool val) const
{
return val ? "true":"false";
}
std::string operator() (value_null const&) const
{
return "null";
}
const char quote_;
};
} // namespace impl
namespace value_adl_barrier {
class value : public value_base
{
friend const value operator+(value const&,value const&);
friend const value operator-(value const&,value const&);
friend const value operator*(value const&,value const&);
friend const value operator/(value const&,value const&);
friend const value operator%(value const&,value const&);
public:
value () noexcept //-- comment out for VC++11
: value_base(value_null()) {}
value (value const& other) = default;
value( value && other) noexcept = default;
template <typename T>
value ( T const& val)
: value_base(typename detail::mapnik_value_type<T>::type(val)) {}
template <typename T>
value ( T && val)
: value_base(std::move(typename detail::mapnik_value_type<T>::type(val))) {}
value & operator=( value const& other) = default;
bool operator==(value const& other) const
{
return util::apply_visitor(impl::equals(),*this,other);
}
bool operator!=(value const& other) const
{
return util::apply_visitor(impl::not_equals(),*this,other);
}
bool operator>(value const& other) const
{
return util::apply_visitor(impl::greater_than(),*this,other);
}
bool operator>=(value const& other) const
{
return util::apply_visitor(impl::greater_or_equal(),*this,other);
}
bool operator<(value const& other) const
{
return util::apply_visitor(impl::less_than(),*this,other);
}
bool operator<=(value const& other) const
{
return util::apply_visitor(impl::less_or_equal(),*this,other);
}
value operator- () const
{
return util::apply_visitor(impl::negate<value>(), *this);
}
bool is_null() const;
template <typename T>
T convert() const
{
return util::apply_visitor(impl::convert<T>(),*this);
}
value_bool to_bool() const
{
return util::apply_visitor(impl::convert<value_bool>(),*this);
}
std::string to_expression_string(char quote = '\'') const
{
return util::apply_visitor(impl::to_expression_string(quote),*this);
}
std::string to_string() const
{
return util::apply_visitor(impl::convert<std::string>(),*this);
}
value_unicode_string to_unicode() const
{
return util::apply_visitor(impl::to_unicode(),*this);
}
value_double to_double() const
{
return util::apply_visitor(impl::convert<value_double>(),*this);
}
value_integer to_int() const
{
return util::apply_visitor(impl::convert<value_integer>(),*this);
}
};
inline const value operator+(value const& p1,value const& p2)
{
return value(util::apply_visitor(impl::add<value>(),p1, p2));
}
inline const value operator-(value const& p1,value const& p2)
{
return value(util::apply_visitor(impl::sub<value>(),p1, p2));
}
inline const value operator*(value const& p1,value const& p2)
{
return value(util::apply_visitor(impl::mult<value>(),p1, p2));
}
inline const value operator/(value const& p1,value const& p2)
{
return value(util::apply_visitor(impl::div<value>(),p1, p2));
}
inline const value operator%(value const& p1,value const& p2)
{
return value(util::apply_visitor(impl::mod<value>(),p1, p2));
}
template <typename charT, typename traits>
inline std::basic_ostream<charT,traits>&
operator << (std::basic_ostream<charT,traits>& out,
value const& v)
{
out << v.to_string();
return out;
}
// hash function
inline std::size_t hash_value(value const& val)
{
return mapnik_hash_value(val);
}
} // namespace value_adl_barrier
using value_adl_barrier::value;
using value_adl_barrier::operator<<;
namespace detail {
struct is_null_visitor
{
bool operator() (value const& val) const
{
return val.is_null();
}
bool operator() (value_null const&) const
{
return true;
}
template <typename T>
bool operator() (T const&) const
{
return false;
}
};
} // namespace detail
inline bool value::is_null() const
{
return util::apply_visitor(mapnik::detail::is_null_visitor(), *this);
}
} // namespace mapnik
#endif // MAPNIK_VALUE_HPP