18554ec0b1
(NOTE: expression_evaluator requires ```using result_type = T1;``` ) Conflicts: src/image.cpp
132 lines
3.5 KiB
C++
132 lines
3.5 KiB
C++
/*****************************************************************************
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*
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* This file is part of Mapnik (c++ mapping toolkit)
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*
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* Copyright (C) 2014 Artem Pavlenko
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*****************************************************************************/
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// mapnik
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#include <mapnik/config.hpp> // needed by msvc
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#include <mapnik/expression_string.hpp> // needed by msvc
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#include <mapnik/expression_node_types.hpp>
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#include <mapnik/expression_node.hpp>
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#include <mapnik/attribute.hpp>
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#include <mapnik/value_types.hpp>
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#include <mapnik/value.hpp>
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namespace mapnik
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{
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struct expression_string
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{
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explicit expression_string(std::string & str)
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: str_(str) {}
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void operator() (value_type const& x) const
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{
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str_ += x.to_expression_string() ;
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}
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void operator() (attribute const& attr) const
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{
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str_ += "[";
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str_ += attr.name();
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str_ += "]";
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}
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void operator() (global_attribute const& attr) const
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{
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str_ += "@";
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str_ += attr.name;
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}
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void operator() (geometry_type_attribute const& /*attr*/) const
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{
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str_ += "[mapnik::geometry_type]";
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}
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template <typename Tag>
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void operator() (binary_node<Tag> const& x) const
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{
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if (x.type() != tags::mult::str() && x.type() != tags::div::str())
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{
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str_ += "(";
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}
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util::apply_visitor(*this,x.left);
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str_ += x.type();
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util::apply_visitor(*this,x.right);
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if (x.type() != tags::mult::str() && x.type() != tags::div::str())
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{
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str_ += ")";
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}
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}
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template <typename Tag>
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void operator() (unary_node<Tag> const& x) const
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{
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str_ += Tag::str();
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str_ += "(";
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util::apply_visitor(*this,x.expr);
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str_ += ")";
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}
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void operator() (regex_match_node const & x) const
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{
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util::apply_visitor(*this,x.expr);
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str_ += x.to_string();
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}
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void operator() (regex_replace_node const & x) const
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{
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util::apply_visitor(*this,x.expr);
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str_ += x.to_string();
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}
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void operator() (unary_function_call const& call) const
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{
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str_ += unary_function_name(call.fun);
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str_ += "(";
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util::apply_visitor(*this,call.arg);
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str_ += ")";
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}
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void operator() (binary_function_call const& call) const
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{
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str_ += binary_function_name(call.fun);
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str_ += "(";
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util::apply_visitor(*this,call.arg1);
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str_ += ",";
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util::apply_visitor(*this,call.arg2);
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str_ += ")";
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}
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private:
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std::string & str_;
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};
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std::string to_expression_string(expr_node const& node)
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{
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std::string str;
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expression_string functor(str);
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util::apply_visitor(std::ref(functor),node);
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return str;
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}
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}
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