expander.cpp

Go to the documentation of this file.

/*
**  Command & Conquer Generals Zero Hour(tm)
**  Copyright 2025 Electronic Arts Inc.
**
**  This program is free software: you can redistribute it and/or modify
**  it under the terms of the GNU General Public License as published by
**  the Free Software Foundation, either version 3 of the License, or
**  (at your option) any later version.
**
**  This program 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 General Public License for more details.
**
**  You should have received a copy of the GNU General Public License
**  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
 
// ---------------------------------------------------------------------------
// File: expander.cpp
// Author: Matthew D. Campbell
// Creation Date: 9/13/2002
// Description: Key/value pair template expansion class
// ---------------------------------------------------------------------------
 
#include "debug.h"
#include "expander.h"
 
Expander::Expander( const std::string& leftMarker, const std::string& rightMarker ) :
    m_left(leftMarker), m_right(rightMarker)
{
}
 
void Expander::addExpansion( const std::string& key, const std::string val )
{
    m_expansions[key] = val;
}
 
void Expander::clear( void )
{
    m_expansions.clear();
}
 
void Expander::expand( const std::string& input,
        std::string& output,
        bool stripUnknown )
{
    output = "";
    unsigned int pos = input.find(m_left);
    unsigned int lastpos = input.npos;
    while (pos != input.npos)
    {
        // first, tack on the non-expansion part we just skipped over
        if (pos > 0)
        {
            if (lastpos == input.npos)
            {
                // first time
                output.append(input.substr(0, pos));
                //DEBUG_LOG(("First time, output='%s'\n", output.c_str()));
            }
            else
            {
                // done this before
                std::string sub = input.substr(lastpos, pos-lastpos);
                //DEBUG_LOG(("*** lastpos = %d, pos=%d, sub='%s'\n", lastpos, pos, sub.c_str()));
                output.append(sub);
                //DEBUG_LOG(("output='%s'\n", output.c_str()));
            }
        }
        else
        {
            //DEBUG_LOG(("pos == 0\n"));
        }
 
        // pos is the first position of a possible expansion
        //DEBUG_LOG(("Looking for endpos via '%s' in '%s'\n", m_right.c_str(), input.substr(pos+m_left.length()).c_str()));
        unsigned int endpos = input.find(m_right, pos+m_left.length());
        //DEBUG_LOG(("substr is %d-%d of '%s'\n", pos, endpos, input.c_str()));
        if (endpos != input.npos)
        {
            // found a complete token - expand it
            std::string sub = input.substr(pos+m_left.length(), endpos-pos-m_left.length());
            //DEBUG_LOG(("found token: '%s'\n", sub.c_str()));
 
            ExpansionMap::iterator it = m_expansions.find(sub);
            if (it == m_expansions.end())
            {
                // unknown key
                if (stripUnknown)
                {
                    //output.append("<<CENSORED>>");
                }
                else
                {
                    output.append(input.substr(pos, endpos-pos+m_right.length()));
                }
            }
            else
            {
                std::string toExpand = it->second;
                std::string expanded = "";
                //DEBUG_LOG(("###### expanding '%s'\n", toExpand.c_str()));
                expand(toExpand, expanded, stripUnknown);
                //DEBUG_LOG(("###### expanded '%s'\n", expanded.c_str()));
                output.append(expanded);
            }
        }
 
        lastpos = endpos+m_right.length();
 
        pos = input.find(m_left, pos+m_left.length());
    }
 
    if (lastpos != input.npos)
    {
        // tack on last bit
        output.append(input.substr(lastpos));
    }
    else if (!output.length() && pos == input.npos && lastpos == input.npos)
    {
        output = input;
    }
}