/////////////////////////////////////////////////////////////////////////////// | |
// state.hpp | |
// | |
// Copyright 2008 Eric Niebler. Distributed under the Boost | |
// Software License, Version 1.0. (See accompanying file | |
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
#ifndef BOOST_XPRESSIVE_DETAIL_CORE_STATE_HPP_EAN_10_04_2005 | |
#define BOOST_XPRESSIVE_DETAIL_CORE_STATE_HPP_EAN_10_04_2005 | |
// MS compatible compilers support #pragma once | |
#if defined(_MSC_VER) && (_MSC_VER >= 1020) | |
# pragma once | |
#endif | |
#include <boost/noncopyable.hpp> | |
#include <boost/xpressive/detail/detail_fwd.hpp> | |
#include <boost/xpressive/detail/core/access.hpp> | |
#include <boost/xpressive/detail/core/action.hpp> | |
#include <boost/xpressive/detail/core/sub_match_vector.hpp> | |
#include <boost/xpressive/detail/utility/sequence_stack.hpp> | |
#include <boost/xpressive/detail/core/regex_impl.hpp> | |
#include <boost/xpressive/regex_constants.hpp> | |
namespace boost { namespace xpressive { namespace detail | |
{ | |
/////////////////////////////////////////////////////////////////////////////// | |
// match_context | |
// | |
template<typename BidiIter> | |
struct match_context | |
{ | |
typedef typename iterator_value<BidiIter>::type char_type; | |
match_context() | |
: results_ptr_(0) | |
, prev_context_(0) | |
, next_ptr_(0) | |
, traits_(0) | |
{ | |
} | |
// pointer to the current match results, passed to actions as a parameter. | |
match_results<BidiIter> *results_ptr_; | |
// The previous match context, if this match_context corresponds to a nested regex invocation | |
match_context<BidiIter> *prev_context_; | |
// If this is a nested match, the "next" sub-expression to execute after the nested match | |
matchable<BidiIter> const *next_ptr_; | |
// A pointer to the current traits object | |
detail::traits<char_type> const *traits_; | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
// attr_context | |
// | |
struct attr_context | |
{ | |
// Slots for holding type-erased pointers to attributes | |
void const **attr_slots_; | |
// The previous attr context, if one exists | |
attr_context *prev_attr_context_; | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
// match_flags | |
// | |
struct match_flags | |
{ | |
bool match_all_; | |
bool match_prev_avail_; | |
bool match_bol_; | |
bool match_eol_; | |
bool match_not_bow_; | |
bool match_not_eow_; | |
bool match_not_null_; | |
bool match_continuous_; | |
bool match_partial_; | |
explicit match_flags(regex_constants::match_flag_type flags) | |
: match_all_(false) | |
, match_prev_avail_(0 != (flags & regex_constants::match_prev_avail)) | |
, match_bol_(match_prev_avail_ || 0 == (flags & regex_constants::match_not_bol)) | |
, match_eol_(0 == (flags & regex_constants::match_not_eol)) | |
, match_not_bow_(!match_prev_avail_ && 0 != (flags & regex_constants::match_not_bow)) | |
, match_not_eow_(0 != (flags & regex_constants::match_not_eow)) | |
, match_not_null_(0 != (flags & regex_constants::match_not_null)) | |
, match_continuous_(0 != (flags & regex_constants::match_continuous)) | |
, match_partial_(0 != (flags & regex_constants::match_partial)) | |
{ | |
} | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
// match_state | |
// | |
template<typename BidiIter> | |
struct match_state | |
: noncopyable | |
{ | |
typedef BidiIter iterator; | |
typedef core_access<BidiIter> access; | |
typedef detail::match_context<BidiIter> match_context; | |
typedef detail::results_extras<BidiIter> results_extras; | |
typedef detail::regex_impl<BidiIter> regex_impl; | |
typedef detail::matchable<BidiIter> matchable; | |
typedef xpressive::match_results<BidiIter> match_results; | |
typedef detail::sub_match_impl<BidiIter> sub_match_impl; | |
typedef detail::actionable actionable; | |
BidiIter cur_; | |
sub_match_impl *sub_matches_; | |
std::size_t mark_count_; | |
BidiIter begin_; | |
BidiIter end_; | |
match_flags flags_; | |
bool found_partial_match_; | |
match_context context_; | |
results_extras *extras_; | |
actionable action_list_; | |
actionable const **action_list_tail_; | |
action_args_type *action_args_; | |
attr_context attr_context_; | |
BidiIter next_search_; | |
/////////////////////////////////////////////////////////////////////////////// | |
// | |
match_state | |
( | |
BidiIter begin | |
, BidiIter end | |
, match_results &what | |
, regex_impl const &impl | |
, regex_constants::match_flag_type flags | |
) | |
: cur_(begin) | |
, sub_matches_(0) | |
, mark_count_(0) | |
, begin_(begin) | |
, end_(end) | |
, flags_(flags) | |
, found_partial_match_(false) | |
, context_() // zero-initializes the fields of context_ | |
, extras_(&core_access<BidiIter>::get_extras(what)) | |
, action_list_() | |
, action_list_tail_(&action_list_.next) | |
, action_args_(&core_access<BidiIter>::get_action_args(what)) | |
, attr_context_() // zero-initializes the fields of attr_context_ | |
, next_search_(begin) | |
{ | |
// reclaim any cached memory in the match_results struct | |
this->extras_->sub_match_stack_.unwind(); | |
// initialize the context_ struct | |
this->init_(impl, what); | |
// move all the nested match_results structs into the match_results cache | |
this->extras_->results_cache_.reclaim_all(access::get_nested_results(what)); | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// reset | |
void reset(match_results &what, regex_impl const &impl) | |
{ | |
this->extras_ = &core_access<BidiIter>::get_extras(what); | |
this->action_list_.next = 0; | |
this->action_list_tail_ = &action_list_.next; | |
this->action_args_ = &core_access<BidiIter>::get_action_args(what); | |
this->attr_context_ = attr_context(); | |
this->context_.prev_context_ = 0; | |
this->found_partial_match_ = false; | |
this->extras_->sub_match_stack_.unwind(); | |
this->init_(impl, what); | |
this->extras_->results_cache_.reclaim_all(access::get_nested_results(what)); | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// push_context | |
// called to prepare the state object for a regex match | |
match_context push_context(regex_impl const &impl, matchable const &next, match_context &prev) | |
{ | |
// save state | |
match_context context = this->context_; | |
// create a new nested match_results for this regex | |
nested_results<BidiIter> &nested = access::get_nested_results(*context.results_ptr_); | |
match_results &what = this->extras_->results_cache_.append_new(nested); | |
// (re)initialize the match context | |
this->init_(impl, what); | |
// create a linked list of match_context structs | |
this->context_.prev_context_ = &prev; | |
this->context_.next_ptr_ = &next; | |
// record the start of the zero-th sub-match | |
this->sub_matches_[0].begin_ = this->cur_; | |
return context; | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// pop_context | |
// called after a nested match failed to restore the context | |
bool pop_context(regex_impl const &impl, bool success) | |
{ | |
match_context &context = *this->context_.prev_context_; | |
if(!success) | |
{ | |
match_results &what = *context.results_ptr_; | |
this->uninit_(impl, what); | |
// send the match_results struct back to the cache | |
nested_results<BidiIter> &nested = access::get_nested_results(what); | |
this->extras_->results_cache_.reclaim_last(nested); | |
} | |
// restore the state | |
this->context_ = context; | |
match_results &results = *this->context_.results_ptr_; | |
this->sub_matches_ = access::get_sub_matches(access::get_sub_match_vector(results)); | |
this->mark_count_ = results.size(); | |
return success; | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// swap_context | |
void swap_context(match_context &context) | |
{ | |
std::swap(this->context_, context); | |
match_results &results = *this->context_.results_ptr_; | |
this->sub_matches_ = access::get_sub_matches(access::get_sub_match_vector(results)); | |
this->mark_count_ = results.size(); | |
} | |
// beginning of buffer | |
bool bos() const | |
{ | |
return this->cur_ == this->begin_; | |
} | |
// end of buffer | |
bool eos() | |
{ | |
return this->cur_ == this->end_ && this->found_partial_match(); | |
} | |
// is this the regex that is currently executing? | |
bool is_active_regex(regex_impl const &impl) const | |
{ | |
return impl.xpr_.get() == this->context_.results_ptr_->regex_id(); | |
} | |
// fetch the n-th sub_match | |
sub_match_impl &sub_match(int n) | |
{ | |
return this->sub_matches_[n]; | |
} | |
// called when a partial match has succeeded | |
void set_partial_match() | |
{ | |
sub_match_impl &sub0 = this->sub_match(0); | |
sub0.first = sub0.begin_; | |
sub0.second = this->end_; | |
sub0.matched = false; | |
} | |
template<typename Traits> | |
Traits const &get_traits() const | |
{ | |
return static_cast<traits_holder<Traits> const *>(this->context_.traits_)->traits(); | |
} | |
private: | |
void init_(regex_impl const &impl, match_results &what) | |
{ | |
regex_id_type const id = impl.xpr_.get(); | |
std::size_t const total_mark_count = impl.mark_count_ + impl.hidden_mark_count_ + 1; | |
// initialize the context and the sub_match vector | |
this->context_.results_ptr_ = &what; | |
this->context_.traits_ = impl.traits_.get(); | |
this->mark_count_ = impl.mark_count_ + 1; | |
this->sub_matches_ = this->extras_->sub_match_stack_.push_sequence(total_mark_count, sub_match_impl(begin_), detail::fill); | |
this->sub_matches_ += impl.hidden_mark_count_; | |
// initialize the match_results struct | |
access::init_match_results(what, id, impl.traits_, this->sub_matches_, this->mark_count_, impl.named_marks_); | |
} | |
void uninit_(regex_impl const &impl, match_results &) | |
{ | |
extras_->sub_match_stack_.unwind_to(this->sub_matches_ - impl.hidden_mark_count_); | |
} | |
bool found_partial_match() | |
{ | |
this->found_partial_match_ = true; | |
return true; | |
} | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
// memento | |
// | |
template<typename BidiIter> | |
struct memento | |
{ | |
sub_match_impl<BidiIter> *old_sub_matches_; | |
std::size_t nested_results_count_; | |
actionable const *action_list_head_; | |
actionable const **action_list_tail_; | |
attr_context attr_context_; | |
}; | |
/////////////////////////////////////////////////////////////////////////////// | |
// save_sub_matches | |
// | |
template<typename BidiIter> | |
inline memento<BidiIter> save_sub_matches(match_state<BidiIter> &state) | |
{ | |
memento<BidiIter> mem = | |
{ | |
state.extras_->sub_match_stack_.push_sequence(state.mark_count_, sub_match_impl<BidiIter>(state.begin_)) | |
, state.context_.results_ptr_->nested_results().size() | |
, state.action_list_.next | |
, state.action_list_tail_ | |
, state.attr_context_ | |
}; | |
state.action_list_.next = 0; | |
state.action_list_tail_ = &state.action_list_.next; | |
std::copy(state.sub_matches_, state.sub_matches_ + state.mark_count_, mem.old_sub_matches_); | |
return mem; | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// restore_action_queue | |
// | |
template<typename BidiIter> | |
inline void restore_action_queue(memento<BidiIter> const &mem, match_state<BidiIter> &state) | |
{ | |
state.action_list_.next = mem.action_list_head_; | |
state.action_list_tail_ = mem.action_list_tail_; | |
*state.action_list_tail_ = 0; | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// restore_sub_matches | |
// | |
template<typename BidiIter> | |
inline void restore_sub_matches(memento<BidiIter> const &mem, match_state<BidiIter> &state) | |
{ | |
typedef core_access<BidiIter> access; | |
nested_results<BidiIter> &nested = access::get_nested_results(*state.context_.results_ptr_); | |
std::size_t count = nested.size() - mem.nested_results_count_; | |
state.extras_->results_cache_.reclaim_last_n(nested, count); | |
std::copy(mem.old_sub_matches_, mem.old_sub_matches_ + state.mark_count_, state.sub_matches_); | |
state.extras_->sub_match_stack_.unwind_to(mem.old_sub_matches_); | |
state.attr_context_ = mem.attr_context_; | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// reclaim_sub_matches | |
// | |
template<typename BidiIter> | |
inline void reclaim_sub_matches(memento<BidiIter> const &mem, match_state<BidiIter> &state, bool success) | |
{ | |
std::size_t count = state.context_.results_ptr_->nested_results().size() - mem.nested_results_count_; | |
if(count == 0) | |
{ | |
state.extras_->sub_match_stack_.unwind_to(mem.old_sub_matches_); | |
} | |
// else we have we must orphan this block of backrefs because we are using the stack | |
// space above it. | |
if(!success) | |
{ | |
state.attr_context_ = mem.attr_context_; | |
} | |
} | |
/////////////////////////////////////////////////////////////////////////////// | |
// traits_cast | |
// | |
template<typename Traits, typename BidiIter> | |
inline Traits const &traits_cast(match_state<BidiIter> const &state) | |
{ | |
return state.template get_traits<Traits>(); | |
} | |
}}} // namespace boost::xpressive::detail | |
#endif |