ledger/src/scope.h

/*
 * Copyright (c) 2003-2010, John Wiegley.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of New Artisans LLC nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @addtogroup expr
 */

/**
 * @file   scope.h
 * @author John Wiegley
 *
 * @ingroup expr
 */
#ifndef _SCOPE_H
#define _SCOPE_H

#include "op.h"

namespace ledger {

struct symbol_t
{
  enum kind_t {
    UNKNOWN,
    FUNCTION,
    OPTION,
    PRECOMMAND,
    COMMAND,
    DIRECTIVE,
    FORMAT
  };

  kind_t	   kind;
  string	   name;
  expr_t::ptr_op_t definition;

  symbol_t() : kind(UNKNOWN), name(""), definition(NULL) {
    TRACE_CTOR(symbol_t, "");
  }
  symbol_t(kind_t _kind, string _name, expr_t::ptr_op_t _definition = NULL)
    : kind(_kind), name(_name), definition(_definition) {
    TRACE_CTOR(symbol_t, "symbol_t::kind_t, string");
  }
  symbol_t(const symbol_t& sym)
    : kind(sym.kind), name(sym.name),
      definition(sym.definition) {
    TRACE_CTOR(symbol_t, "copy");
  }
  ~symbol_t() throw() {
    TRACE_DTOR(symbol_t);
  }

  bool operator<(const symbol_t& sym) const {
    return kind < sym.kind || name < sym.name;
  }

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive& ar, const unsigned int /* version */) {
    ar & kind;
    ar & name;
    ar & definition;
  }
#endif // HAVE_BOOST_SERIALIZATION
};

class scope_t
{
public:
  static scope_t * default_scope;

  explicit scope_t() {
    TRACE_CTOR(scope_t, "");
  }
  virtual ~scope_t() {
    TRACE_DTOR(scope_t);
  }

  virtual void define(const symbol_t::kind_t, const string&,
		      expr_t::ptr_op_t) {}
  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
				  const string& name) = 0;

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive&, const unsigned int /* version */) {}
#endif // HAVE_BOOST_SERIALIZATION
};

class child_scope_t : public noncopyable, public scope_t
{
public:
  scope_t * parent;

  explicit child_scope_t() : parent(NULL) {
    TRACE_CTOR(child_scope_t, "");
  }
  explicit child_scope_t(scope_t& _parent)
    : parent(&_parent) {
    TRACE_CTOR(child_scope_t, "scope_t&");
  }
  virtual ~child_scope_t() {
    TRACE_DTOR(child_scope_t);
  }

  virtual void define(const symbol_t::kind_t kind,
		      const string& name, expr_t::ptr_op_t def) {
    if (parent)
      parent->define(kind, name, def);
  }

  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
				  const string& name) {
    if (parent)
      return parent->lookup(kind, name);
    return NULL;
  }

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive& ar, const unsigned int /* version */) {
    ar & boost::serialization::base_object<scope_t>(*this);
    ar & parent;
  }
#endif // HAVE_BOOST_SERIALIZATION
};

class symbol_scope_t : public child_scope_t
{
  typedef std::map<symbol_t, expr_t::ptr_op_t> symbol_map;

  optional<symbol_map> symbols;

public:
  explicit symbol_scope_t() {
    TRACE_CTOR(symbol_scope_t, "");
  }
  explicit symbol_scope_t(scope_t& _parent) : child_scope_t(_parent) {
    TRACE_CTOR(symbol_scope_t, "scope_t&");
  }
  virtual ~symbol_scope_t() {
    TRACE_DTOR(symbol_scope_t);
  }

  virtual void define(const symbol_t::kind_t kind, const string& name,
		      expr_t::ptr_op_t def);

  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
				  const string& name);

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive& ar, const unsigned int /* version */) {
    ar & boost::serialization::base_object<child_scope_t>(*this);
    ar & symbols;
  }
#endif // HAVE_BOOST_SERIALIZATION
};

class call_scope_t : public child_scope_t
{
  value_t args;

public:
  explicit call_scope_t(scope_t& _parent) : child_scope_t(_parent) {
    TRACE_CTOR(call_scope_t, "scope_t&");
  }
  virtual ~call_scope_t() {
    TRACE_DTOR(call_scope_t);
  }

  void set_args(const value_t& _args) {
    args = _args;
  }
  value_t& value() {
    return args;
  }

  value_t& operator[](const std::size_t index) {
    return args[index];
  }
  const value_t& operator[](const std::size_t index) const {
    return args[index];
  }

  void push_front(const value_t& val) {
    args.push_front(val);
  }
  void push_back(const value_t& val) {
    args.push_back(val);
  }
  void pop_back() {
    args.pop_back();
  }

  typedef value_t::sequence_t::iterator iterator;

  value_t::sequence_t::iterator begin() {
    return args.begin();
  }
  value_t::sequence_t::iterator end() {
    return args.end();
  }

  typedef value_t::sequence_t::const_iterator const_iterator;

  value_t::sequence_t::const_iterator begin() const {
    return args.begin();
  }
  value_t::sequence_t::const_iterator end() const {
    return args.end();
  }

  std::size_t size() const {
    return args.size();
  }
  bool empty() const {
    return args.size() == 0;
  }

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  explicit call_scope_t() {
    TRACE_CTOR(call_scope_t, "");
  }

  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive& ar, const unsigned int /* version */) {
    ar & boost::serialization::base_object<child_scope_t>(*this);
    ar & args;
  }
#endif // HAVE_BOOST_SERIALIZATION
};

class bind_scope_t : public child_scope_t
{
  bind_scope_t();

public:
  scope_t& grandchild;

  explicit bind_scope_t(scope_t& _parent,
			scope_t& _grandchild)
    : child_scope_t(_parent), grandchild(_grandchild) {
    TRACE_CTOR(bind_scope_t, "scope_t&, scope_t&");
  }
  virtual ~bind_scope_t() {
    TRACE_DTOR(bind_scope_t);
  }

  virtual void define(const symbol_t::kind_t kind, const string& name,
		      expr_t::ptr_op_t def) {
    parent->define(kind, name, def);
    grandchild.define(kind, name, def);
  }

  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
				  const string& name) {
    if (expr_t::ptr_op_t def = grandchild.lookup(kind, name))
      return def;
    return child_scope_t::lookup(kind, name);
  }

#if defined(HAVE_BOOST_SERIALIZATION)
private:
  /** Serialization. */

  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive& ar, const unsigned int /* version */) {
    ar & boost::serialization::base_object<child_scope_t>(*this);
    ar & grandchild;
  }
#endif // HAVE_BOOST_SERIALIZATION
};

template <typename T>
T * search_scope(scope_t * ptr)
{
  if (T * sought = dynamic_cast<T *>(ptr))
    return sought;

  if (bind_scope_t * scope = dynamic_cast<bind_scope_t *>(ptr)) {
    if (T * sought = search_scope<T>(&scope->grandchild))
      return sought;
    return search_scope<T>(scope->parent);
  }
  else if (child_scope_t * scope = dynamic_cast<child_scope_t *>(ptr)) {
    return search_scope<T>(scope->parent);
  }
  return NULL;
}

template <typename T>
inline T& find_scope(child_scope_t& scope, bool skip_this = true)
{
  if (T * sought = search_scope<T>(skip_this ? scope.parent : &scope))
    return *sought;

  throw_(std::runtime_error, _("Could not find scope"));
  return reinterpret_cast<T&>(scope); // never executed
}

class value_scope_t : public scope_t
{
  value_t value;

  value_t get_value(call_scope_t&) {
    return value;
  }

public:
  value_scope_t(const value_t& _value) : value(_value) {}
  
  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
				  const string& name)
  {
    if (kind != symbol_t::FUNCTION)
      return NULL;

    if (name == "value")
      return MAKE_FUNCTOR(value_scope_t::get_value);

    return NULL;
  }
};

} // namespace ledger

#endif // _SCOPE_H