StringMapper-example.cpp

Expands a std::string containing variables like "Hello, ${name}!" to a literal std::string. StringMapper parses a given std::string, it splits the std::string into segments containing literals and variables in turn. The result is stored in a list of Stringlet:s. The variables are provided to a StringMap by means of a std::map<std::string,T> .

/*
 
    Copyright 2001 - 2017  Markus Peura, Finnish Meteorological Institute (First.Last@fmi.fi)
 
 
    This file is part of Rack for C++.
 
    Rack is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    any later version.
 
    Rack 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 Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with Rack.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
/*
REQUIRE: drain/{Caster,Castable,Log,Reference,RegExp,Sprinter,String,Type,TypeUtils,TextStyle,Variable,VariableBase}.cpp
REQUIRE: drain/util/{FileInfo,JSON,StringMapper,TextReader}.cpp
 
g+s+ -I. drain/examples/StringMapper-example.cpp drain/util/{Caster,Castable,JSONwriter,RegExp,String,StringMapper,Type,Variable,Log}.cpp -o StringMapper-example
 */
#include <cmath>
#include <iostream>
#include "drain/util/StringMapper.h"
 
//using namespace std;
using namespace drain;
 
int main(int argc, char **argv){
 
    StringMapper mapper; //(argv[1]);
 
    if (argc < 4){
        std::cerr << "Usage:\n  " << argv[0] << " <keychars> <sample-string>  <key>=<value> <key2>=<value2> ...\n";
        std::cerr << "Example:\n  " << argv[0] << " '[a-zA-Z0-9]+'  'Hello, ${e} and ${pi}! My name is ${x}.'  e=world  x=test\n";
        std::cerr << "Example:\n  " << argv[0] << " '\\w+' 'Hello, ${e} and ${pi}! My name is ${x}.'  e=world  x=test\n";
        std::cerr << "Example:\n  " << argv[0] << " '[a-zA-Z0-9][a-zA-Z0-9_:]*' 'Hello Neper, ${e} ${e|%4.2f} ${e|%06.2f} ${e|:6:2}..'  x=test\n";
        mapper.setValidChars("[a-zA-Z0-9][a-zA-Z0-9_:]*");
 
        return 1;
    }
 
    drain::getLog().setVerbosity(LOG_DEBUG);
    drain::getLog().USE_VT100 = true;
    Logger mout(__FILE__, __FUNCTION__);
 
 
    mapper.setValidChars(argv[1]);
 
    mout.special(mapper);
 
    mapper.parse(argv[2], true);
 
    mout.warn("Initial parsed state: ", mapper);
 
    std::map<std::string,std::string> m;
    m["sqrt2"]  = "1.41421356237309504880";
    m["e"]  = "2.7182818284590452354";
 
    for (int i = 3; i < argc; ++i) {
        const std::string a = argv[i];
        std::size_t j = a.find('=');
        if (j != std::string::npos){
            m[a.substr(0,j)] = a.substr(j+1);
        }
        else {
            std::cerr << "arg[" << i << "]=" << a <<" not an assignment: <key>=<value>\n";
        }
 
    }
 
    std::cout << "Debugging after assignments:\n";
    mapper.debug(std::cerr, m);
    std::cout << '\n';
 
    std::cout << "Alternative 1: format a map using StringMapper:\n";
    std::cout << "-1 = keep:  ";
    mapper.toStream(std::cout, m, -1); // true);
    std::cout << '\n';
    std::cout << " 0 = clear: ";
    mapper.toStream(std::cout, m, 0);
    std::cout << '\n';
    std::cout << ">0 = char:  ";
    mapper.toStream(std::cout, m, 'X');
    std::cout << '\n';
    std::cout << '\n';
 
 
    std::cout << "Alternative 2: expanding variables inside the StringMapper, ie. turning its variables to constants.\n";
 
    std::cout << "Original string:\n  ";
    std::cout << mapper << std::endl;
 
    std::cout << "After expansion by given variables:\n  ";
    mapper.expand(m);
    std::cout << mapper << std::endl;
 
    std::cout << "After further expansion by another map (pi=3.14, e=2.73):\n  ";
    std::map<std::string,float> m2;
    m2["pi"] = M_PI;
    m2["e"]  = M_E;
    mapper.expand(m2);
    std::cout << mapper << std::endl;
 
    return 0;
}