parsing.cpp raw

   1  // Copyright (c) 2018-2022 The Limenka developers
   2  // Distributed under the MIT software license, see the accompanying
   3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4  
   5  #include <script/parsing.h>
   6  
   7  #include <span.h>
   8  
   9  #include <algorithm>
  10  #include <cstddef>
  11  #include <string>
  12  
  13  namespace script {
  14  
  15  bool Const(const std::string& str, Span<const char>& sp)
  16  {
  17      if ((size_t)sp.size() >= str.size() && std::equal(str.begin(), str.end(), sp.begin())) {
  18          sp = sp.subspan(str.size());
  19          return true;
  20      }
  21      return false;
  22  }
  23  
  24  bool Func(const std::string& str, Span<const char>& sp)
  25  {
  26      if ((size_t)sp.size() >= str.size() + 2 && sp[str.size()] == '(' && sp[sp.size() - 1] == ')' && std::equal(str.begin(), str.end(), sp.begin())) {
  27          sp = sp.subspan(str.size() + 1, sp.size() - str.size() - 2);
  28          return true;
  29      }
  30      return false;
  31  }
  32  
  33  Span<const char> Expr(Span<const char>& sp)
  34  {
  35      int level = 0;
  36      auto it = sp.begin();
  37      while (it != sp.end()) {
  38          if (*it == '(' || *it == '{') {
  39              ++level;
  40          } else if (level && (*it == ')' || *it == '}')) {
  41              --level;
  42          } else if (level == 0 && (*it == ')' || *it == '}' || *it == ',')) {
  43              break;
  44          }
  45          ++it;
  46      }
  47      Span<const char> ret = sp.first(it - sp.begin());
  48      sp = sp.subspan(it - sp.begin());
  49      return ret;
  50  }
  51  
  52  } // namespace script
  53