VarNames.cpp

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/* Frobby: Software for monomial ideal computations.
   Copyright (C) 2007 Bjarke Hammersholt Roune (www.broune.com)
 
   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 2 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/.
*/
#include "stdinc.h"
#include "VarNames.h"
 
#include "error.h"
#include "FrobbyStringStream.h"
 
#include <limits>
 
VarNames::VarNames() {
}
 
VarNames::VarNames(size_t varCount) {
  for (size_t i = 0; i < varCount; ++i) {
    FrobbyStringStream out;
    out << 'x' << (i + 1);
    addVar(out);
  }
}
 
VarNames::VarNames(const VarNames& names) {
  *this = names;
}
 
VarNames::~VarNames() {
  clear();
}
 
bool VarNames::addVar(const string& name) {
  ASSERT(name != "");
 
  pair<VarNameMap::iterator, bool> p =_nameToIndex.insert
    (make_pair(name, _indexToName.size()));
  if (!p.second) {
    ASSERT(contains(name));
    return false;
  }
 
  try {
    _indexToName.push_back(&(p.first->first)); // TODO: fix to vector of iters
  } catch (...) {
    _nameToIndex.erase(p.first);
    throw;
  }
 
  if (getVarCount() == invalidIndex)
    reportError("Too many variable names");
 
  ASSERT(contains(name));
  return true;
}
 
void VarNames::addVarSyntaxCheckUnique(const Scanner& in,
                                       const string& name) {
  if (!addVar(name))
    reportSyntaxError(in, "The variable " + name + " is declared twice.");
  ASSERT(contains(name));
}
 
bool VarNames::operator<(const VarNames& names) const {
  return lexicographical_compare(_indexToName.begin(),
                                 _indexToName.end(),
                                 names._indexToName.begin(),
                                 names._indexToName.end(),
                                 compareNames);
}
 
size_t VarNames::getIndex(const string& name) const {
  VarNameMap::const_iterator it = _nameToIndex.find(name);
  if (it == _nameToIndex.end())
    return invalidIndex;
  else
    return it->second;
}
 
bool VarNames::contains(const string& name) const {
  return getIndex(name) != invalidIndex;
}
 
bool VarNames::namesAreDefault() const {
  VarNames names(getVarCount());
  return *this == names;
}
 
const string& VarNames::getName(size_t index) const {
  ASSERT(index < _indexToName.size());
 
  return *(_indexToName[index]);
}
 
void VarNames::clear() {
  _nameToIndex.clear();
  _indexToName.clear();
}
 
bool VarNames::empty() const {
  return _indexToName.empty();
}
 
VarNames& VarNames::operator=(const VarNames& names) {
  if (this != &names) {
    clear();
 
    _indexToName.reserve(names.getVarCount());
 
    for (size_t var = 0; var < names.getVarCount(); ++var)
      addVar(names.getName(var));
  }
 
  return *this;
}
 
bool VarNames::operator==(const VarNames& names) const {
  if (getVarCount() != names.getVarCount())
    return false;
 
  for (size_t var = 0; var < getVarCount(); ++var)
    if (getName(var) != names.getName(var))
      return false;
 
  return true;
}
 
bool VarNames::operator!=(const VarNames& names) const {
  return !operator==(names);
}
 
void VarNames::swapVariables(size_t a, size_t b) {
  ASSERT(a < getVarCount());
  ASSERT(b < getVarCount());
 
  ASSERT(_nameToIndex[*_indexToName[a]] == a);
  ASSERT(_nameToIndex[*_indexToName[b]] == b);
 
  if (a == b)
    return;
 
  std::swap(_indexToName[a], _indexToName[b]);
  _nameToIndex[*_indexToName[a]] = a;
  _nameToIndex[*_indexToName[b]] = b;
 
  ASSERT(_nameToIndex[*_indexToName[a]] == a);
  ASSERT(_nameToIndex[*_indexToName[b]] == b);
}
 
void VarNames::projectVar(size_t index) {
  ASSERT(index < getVarCount());
 
  VarNames names;
  for (size_t var = 0; var < getVarCount(); ++var)
    if (var != index)
      names.addVar(getName(var));
  *this = names;
}
 
void VarNames::toString(string& str) const {
  str.clear();
  for (size_t i = 0; i < getVarCount(); ++i) {
    if (i != 0)
      str += ", ";
    str += getName(i);
  }
}
 
void VarNames::print(FILE* file) const {
  fputs("VarNames(", file);
  for (size_t i = 0; i < getVarCount(); ++i) {
    if (i != 0)
      fputs(", ", file);
    fprintf(file, "%lu<->\"%s\"", (unsigned long)i, getName(i).c_str());
  }
  fputs(")\n", file);
}
 
void VarNames::swap(VarNames& names) {
  _indexToName.swap(names._indexToName);
  _nameToIndex.swap(names._nameToIndex);
}
 
bool VarNames::compareNames(const string* a, const string* b) {
  return *a < *b;
}