cpp

// pgen2.cc

#include "pgen2.h"

#include <vector>

namespace pnode {

PNode::PNode(int typ, syntax_asdl::Token* tok, List<PNode*>*)

    : typ(typ), tok(tok), children() {

}

void PNode::AddChild(PNode* node) {

  children.push_back(node);

}

PNode* PNode::GetChild(int i) {

  int j = i;

  if (j < 0) {

    j += NumChildren();

  }

  return children[j];

}

int PNode::NumChildren() {

  return children.size();

}

// TODO: It would be nicer to reuse the std::deque arena_ throughout the whole

// program.  Rather than new/delete for parsing each YSH expression.

PNodeAllocator::PNodeAllocator() : arena_(new std::deque<PNode>()) {

}

PNode* PNodeAllocator::NewPNode(int typ, syntax_asdl::Token* tok) {

  arena_->emplace_back(typ, tok, nullptr);

  return &(arena_->back());

}

void PNodeAllocator::Clear() {

  delete arena_;

  arena_ = nullptr;

}

}  // namespace pnode