roza/lib/SymTable.cpp

#include "SymTable.hpp"

namespace roza
{
  /*static*/ int SymTable::addr = 0;

  /*explicit*/ SymTable::SymTable()
  {
  }

  /*explicit*/ SymTable::SymTable(SymTable const& sym_table)
  {
    m_scope = sym_table.m_scope;
    m_entries = sym_table.m_entries;
  }

  /*virtual*/ SymTable::~SymTable()
  {
  }

  void SymTable::enter_scope()
  {
    m_scope++;
  }

  void SymTable::leave_scope()
  {
    auto iter = std::begin(m_entries);

    while (iter != std::end(m_entries))
      {
        if (iter->scope >= m_scope)
          {
            iter = m_entries.erase(iter);
          }
        else
          {
            iter++;
          }
      }

    m_scope--;
  }

  int SymTable::declare(std::string const& name, std::shared_ptr<Node> node)
  {
    assert(!exists_in_scope(name));

    m_entries.push_back(SymEntry {
        name,
        SymTable::addr++,
        m_scope,
        node,
        false
      });

    return SymTable::addr - 1;
  }

  int SymTable::declare_mut(std::string const& name, std::shared_ptr<Node> node)
  {
    int addr = declare(name, node);
    m_entries.back().is_mut = true;

    return addr;
  }

  SymEntry& SymTable::find(std::string const& name)
  {
    assert(exists(name));

    size_t idx = 0;
    int scope = -1;

    size_t i = 0;

    for (auto const& entry: m_entries)
      {
        if (entry.name == name && entry.scope > scope)
          {
            idx = i;
            scope = entry.scope;
          }

        i++;
      }

    assert(scope >= 0);

    return m_entries[idx];
  }

  SymEntry const& SymTable::find(std::string const& name) const
  {
    assert(exists(name));

    size_t idx = 0;
    int scope = -1;

    size_t i = 0;

    for (auto const& entry: m_entries)
      {
        if (entry.name == name && entry.scope > scope)
          {
            idx = i;
            scope = entry.scope;
          }

        i++;
      }

    assert(scope >= 0);

    return m_entries[idx];
  }

  bool SymTable::exists(std::string const& name) const
  {
    for (auto const& entry: m_entries)
      {
        if (entry.name == name) { return true; }
      }

    return false;
  }

  bool SymTable::exists_in_scope(std::string const& name) const
  {
    for (auto const& entry: m_entries)
      {
        if (entry.name == name && entry.scope >= m_scope)
          {
            return true;
          }
      }

    return false;
  }
}