/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying

   file LICENSE.rst or https://cmake.org/licensing for details.  */

#include "cmGeneratorExpressionLexer.h"

cmGeneratorExpressionLexer::cmGeneratorExpressionLexer() = default;

static void InsertText(char const* upto, char const* c,

                       std::vector<cmGeneratorExpressionToken>& result)

{

  if (upto != c) {

    result.emplace_back(cmGeneratorExpressionToken::Text, upto, c - upto);

  }

}

std::vector<cmGeneratorExpressionToken> cmGeneratorExpressionLexer::Tokenize(

  std::string const& input)

{

  std::vector<cmGeneratorExpressionToken> result;

  if (input.find('$') == std::string::npos) {

    result.emplace_back(cmGeneratorExpressionToken::Text, input.c_str(),

                        input.size());

    return result;

  }

  char const* c = input.c_str();

  char const* upto = c;

  for (; *c; ++c) {

    switch (*c) {

      case '$':

        if (c[1] == '<') {

          InsertText(upto, c, result);

          result.emplace_back(cmGeneratorExpressionToken::BeginExpression, c,

                              2);

          upto = c + 2;

          ++c;

          this->SawBeginExpression = true;

        }

        break;

      case '>':

        InsertText(upto, c, result);

        result.emplace_back(cmGeneratorExpressionToken::EndExpression, c, 1);

        upto = c + 1;

        this->SawGeneratorExpression = this->SawBeginExpression;

        break;

      case ':':

        InsertText(upto, c, result);

        result.emplace_back(cmGeneratorExpressionToken::ColonSeparator, c, 1);

        upto = c + 1;

        break;

      case ',':

        InsertText(upto, c, result);

        result.emplace_back(cmGeneratorExpressionToken::CommaSeparator, c, 1);

        upto = c + 1;

        break;

      default:

        break;

    }

  }

  InsertText(upto, c, result);

  return result;

}