parsing.cpp raw

   1  // Copyright (c) 2018-present The Bitcoin Core 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 <algorithm>
   8  #include <cstddef>
   9  #include <string>
  10  
  11  namespace script {
  12  
  13  bool Const(const std::string& str, std::span<const char>& sp, bool skip)
  14  {
  15      if ((size_t)sp.size() >= str.size() && std::equal(str.begin(), str.end(), sp.begin())) {
  16          if (skip) sp = sp.subspan(str.size());
  17          return true;
  18      }
  19      return false;
  20  }
  21  
  22  bool Func(const std::string& str, std::span<const char>& sp)
  23  {
  24      if ((size_t)sp.size() >= str.size() + 2 && sp[str.size()] == '(' && sp[sp.size() - 1] == ')' && std::equal(str.begin(), str.end(), sp.begin())) {
  25          sp = sp.subspan(str.size() + 1, sp.size() - str.size() - 2);
  26          return true;
  27      }
  28      return false;
  29  }
  30  
  31  std::span<const char> Expr(std::span<const char>& sp)
  32  {
  33      int level = 0;
  34      auto it = sp.begin();
  35      while (it != sp.end()) {
  36          if (*it == '(' || *it == '{') {
  37              ++level;
  38          } else if (level && (*it == ')' || *it == '}')) {
  39              --level;
  40          } else if (level == 0 && (*it == ')' || *it == '}' || *it == ',')) {
  41              break;
  42          }
  43          ++it;
  44      }
  45      std::span<const char> ret = sp.first(it - sp.begin());
  46      sp = sp.subspan(it - sp.begin());
  47      return ret;
  48  }
  49  
  50  } // namespace script
  51