ivl/details/array_nd/impl/subarray_details/subarray_nd_iterator.hpp

/* This file is part of the ivl C++ library <http://image.ntua.gr/ivl>.
   A C++ template library extending syntax towards mathematical notation.

   Copyright (C) 2012 Yannis Avrithis <iavr@image.ntua.gr>
   Copyright (C) 2012 Kimon Kontosis <kimonas@image.ntua.gr>

   ivl is free software; you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License 
   version 3 as published by the Free Software Foundation.

   Alternatively, you can redistribute it and/or modify it under the terms 
   of the GNU General Public License version 2 as published by the Free 
   Software Foundation.

   ivl is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
   See the GNU General Public License for more details.

   You should have received a copy of the GNU General Public License 
   and a copy of the GNU Lesser General Public License along 
   with ivl. If not, see <http://www.gnu.org/licenses/>. */

#ifndef IVL_CORE_DETAILS_ITERATOR_SUBARRAY_ND_ITERATOR_HPP
#define IVL_CORE_DETAILS_ITERATOR_SUBARRAY_ND_ITERATOR_HPP


namespace ivl {

namespace data {
/*
template <class T, class IT, bool REF_IS_ND, bool CONST, int SPECIALIZED = 0>
class subarray_nd_iterator
{
};
*/

template <class T, class IT, class CONST_IT,
        bool REF_IS_ND, bool CONST, int SPECIALIZED = 0,
        bool PAST_END_CAPABLE = true>
class subarray_nd_iterator
: public data::data_details::
        iter_operator_expander<
                subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, CONST, SPECIALIZED,
                PAST_END_CAPABLE>,
                        T, CONST,
                        typename types::remove_const<typename IT::reference>::type>
{
private:
        template <class J, class Y, class V, bool R, bool C, int S, bool P>
        friend class subarray_nd_iterator;

        friend class array_nd_details::
                subarray_tools<typename types::t_expr<REF_IS_ND>::type>;

        typedef array_nd_details::subarray_common_tools ctool;

        typedef array_nd_details::
                subarray_tools<typename types::t_expr<REF_IS_ND>::type> tool;

        template <class X, class Y, bool C, class Z>
        friend class data::data_details::iter_operator_expander;

        typedef typename types::apply_const<T, types::t_expr<CONST> >
                ::type best_value_type;

        typedef typename types::apply_const<typename IT::reference,
                types::t_expr<CONST> >::type best_ref_type;

        // this class is used to disable specific specialization members
        // this class is used to disable non-const operator [] for const_operators
        class not_a_type { operator size_t() { return 0; } };

        typedef typename types::t_if<types::t_expr<CONST>, not_a_type,
                types::code_word<> >::type invalid_if_const;

        typedef array_nd_details::subarray_common_tools::sub_type sub_type;

protected:
/*      typedef typename types::t_if<types::t_expr<
                (!REF_IS_ND && PAST_END_CAPABLE &&
                !data::iterator_extended_traits<IT>::is_past_end_capable::value)>,
                data::past_end_capable_iterator<IT>, IT>::type ref_iter_type;
*/
        typedef iterator_nd_details::it_wrapper<typename IT::value_type, IT,
                PAST_END_CAPABLE && !REF_IS_ND, types::is_ptr<IT>::value> ref_iter_type;
/*
typename types::t_if<types::t_expr<REF_IS_ND && PAST_END_CAPABLE &&
                !data::iterator_extended_traits<IT>::is_past_end_capable::value)>,
                data::past_end_capable_iterator<IT>, IT>::type ref_iter_type;
*/
        ref_iter_type ptr;
        size_t step;
        ptrdiff_t posit;
        const size_t* idx;
        ptrdiff_t* diff;
        ptrdiff_t cur_pos; // -1 means either no array or singleton array
        sub_type type_deprecated;
        ivl::array<size_t, tiny> pos;

        inline typename types::apply_const<best_ref_type>::type base(
                types::code_word<> ok = types::code_word<>()) const
                { return (*ptr); }

        inline best_ref_type base(
                invalid_if_const disable = invalid_if_const())
                { return (*ptr); }


public:
        typedef subarray_nd_iterator this_type;

        // iterator_traits
        typedef std::random_access_iterator_tag iterator_category;
        typedef T value_type;
        typedef ptrdiff_t difference_type;
        typedef best_value_type* pointer;
        typedef best_ref_type reference;

        typedef types::t_false has_base_iterator;

        typedef IT reference_iterator;

        struct iter_nd_dir_type
        {
                IT ptr;
        };

//todo: basically i need to put dir_type instead of iterator in the definition
// of border_walker(in tool), though the problem is i have not created such a
// type for array. that would be useful for many reasons. used also in the
// iterator, in array, instead of iters, for moving around. and hold only
// the 4 iterators begin end rbegin rend in the iters array. (though that'd
// make 2 pointers/iter overhead).

        /*typedef typename tool::template
                iter_nd_border_walker<subarray_nd_iterator<T, CONST_IT, CONST_IT,
                        REF_IS_ND, true, 0> > iter_nd_border_walker;*/
        typedef typename tool::template
                iter_nd_border_walker<CONST_IT> iter_nd_border_walker;

        // constructors
        subarray_nd_iterator() { }
        template<class S>
        subarray_nd_iterator(
                const IT& ptr,
                size_t step,
                ptrdiff_t posit,
                const size_t* idx,
                ptrdiff_t* diff,
                ptrdiff_t cur_pos,
                sub_type type,
                const array<size_t, S>& pos) :
                        ptr(types::code_word<>(), ptr), step(step), posit(posit), idx(idx), diff(diff),
                        cur_pos(cur_pos), type_deprecated(type), pos(pos)
                { }

        subarray_nd_iterator(
                const IT& ptr,
                size_t step,
                ptrdiff_t posit,
                const size_t* idx,
                ptrdiff_t* diff,
                ptrdiff_t cur_pos,
                sub_type type,
                size_t pos_size, size_t pos_dim, size_t pos_val
                ) :
                        ptr(types::code_word<>(), ptr), step(step), posit(posit), idx(idx), diff(diff),
                        cur_pos(cur_pos), type_deprecated(type)
                { pos.resize(pos_size, 0); pos[pos_dim] = pos_val; }


        subarray_nd_iterator(
                const IT& ptr,
                size_t step,
                ptrdiff_t posit,
                const size_t* idx,
                ptrdiff_t* diff,
                ptrdiff_t cur_pos,
                sub_type type,
                size_t pos_size
                ) :
                        ptr(types::code_word<>(), ptr), step(step), posit(posit), idx(idx), diff(diff),
                        cur_pos(cur_pos), type_deprecated(type), pos(pos_size, size_t(0))
                { }

        template<class S>
        subarray_nd_iterator(
                const IT& ptr,
                size_t step,
                ptrdiff_t posit,
                const size_t* idx,
                ptrdiff_t* diff,
                ptrdiff_t cur_pos,
                sub_type type,
                array<size_t, S> pos, size_t pos_dim, size_t pos_val
                ) :
                        ptr(types::code_word<>(), ptr), step(step), posit(posit), idx(idx), diff(diff),
                        cur_pos(cur_pos), type_deprecated(type), pos(pos)
                { pos[pos_dim] = pos_val; }

        subarray_nd_iterator(const this_type& it) :
                ptr(it.ptr), step(it.step), posit(it.posit), idx(it.idx), diff(it.diff),
                cur_pos(it.cur_pos), type_deprecated(it.type_deprecated), pos(it.pos) { }



        template <bool C, int S>
        subarray_nd_iterator(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                PAST_END_CAPABLE>& it)
                :
                ptr(types::code_word<>(), it.ptr), step(it.step), posit(it.posit), idx(it.idx), diff(it.diff),
                cur_pos(it.cur_pos), type_deprecated(it.type_deprecated), pos(it.pos) { }



        //copy same type iterator
        this_type& operator=(const this_type& it)
        {
                ptr = it.ptr;
                step = it.step;
                posit = it.posit;
                idx = it.idx;
                diff = it.diff;
                cur_pos = it.cur_pos;
                type_deprecated = it.type_deprecated;
                pos = it.pos;
                return *this;
        }

        //copy relevant type iterator
        template <bool C, int S>
        this_type& operator=(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                PAST_END_CAPABLE>& it)
        {
                using namespace types;

                ptr = it.ptr;
                step = it.step;

                // skip these assignments
                r_if<t_expr<S != 1> >(posit, types::skip()) = it.posit;
                r_if<t_expr<S != 1> >(idx, types::skip()) = it.idx;
                r_if<t_expr<S != 1> >(diff, types::skip()) = it.diff;
                //r_if<t_expr<S != 1> >(cur_pos, types::skip()) = it.cur_pos;
                cur_pos = r_if<t_expr<S != 1> >(it.cur_pos, -1);

                type_deprecated = it.type_deprecated;
                pos = it.pos;
                return *this;
        }


        // members

        // increment-decrement
        inline this_type& operator++()
        {
                //TODO: create the specialized versions:
                // 1: for step
                // 2: for array
                // 0: for the following with if:
                if(cur_pos >= 0) {
                        ptr += *(diff++);
                        posit++;

                } else {
                        ptr += step;
                }
                return *this;
        }

        inline this_type& operator--()
        {
                if(cur_pos >= 0) {
                        ptr -= *(--diff);
                        posit--;

                } else {
                        ptr -= step;
                }
                return *this;
        }

        this_type operator++(int) { this_type tmp(*this); ++(*this); return tmp; }
        this_type operator--(int) { this_type tmp(*this); --(*this); return tmp; }

        this_type& operator +=(ptrdiff_t j)
        {
                //TODO: create the specialized versions:
                // 1: for step
                // 2: for array
                // 0: for the following with if:
                if(cur_pos >= 0) {

                        size_t last = idx[posit];
                        posit += j;
                        diff += j;
                        ptr += step * (idx[posit] - last);

                } else {
                        ptr += step * j;
                }
                return *this;
        }

        this_type& operator -=(ptrdiff_t j)
        {
                //TODO: create the specialized versions:
                // 1: for step
                // 2: for array
                // 0: for the following with if:
                if(cur_pos >= 0) {

                        size_t last = idx[posit];
                        posit -= j;
                        diff -= j;
                        ptr += step * (idx[posit] - last);

                } else {
                        ptr -= step * j;
                }
                return *this;
        }

        this_type& operator +=(const iter_nd_border_walker& b)
        {
                //TODO: create the specialized versions:
                // 1: for step, which excludes posit
                // 2: for array, and 0: same as below
                // TODO: ensure non-array has invalid curpos!!
                if(b.cur_pos >= 0) { // b is for an array dimension
                        if(cur_pos == b.cur_pos) {
                                posit += b.len;
                                diff += b.len;
                        } else {
                                pos[b.cur_pos] += b.len;
                        }
                }

                tool::move_ref_along(this->ptr, b.it, b.step, 1);

                return *this;
        }

        this_type& operator -=(const iter_nd_border_walker& b)
        {
                //TODO: create the specialized versions:
                // 1: for step, which excludes posit
                // 2: for array, and 0: same as below
                if(b.cur_pos >= 0) { // b is for an array dimension
                        if(cur_pos == b.cur_pos) {
                                posit -= b.len;
                                diff -= b.len;
                        } else {
                                pos[b.cur_pos] -= b.len;
                        }
                }

                tool::move_ref_along(this->ptr, b.it, -b.step, 1);


                return *this;
        }

        template <bool C, int S, bool P>
        void inc_along_other_dim_at_begin(const subarray_nd_iterator<T, IT, CONST_IT,
                                                REF_IS_ND, C, S, P>& it)
        // 1. other it must be at begin
        // 2. must be of different direction
        {
                //TODO: create specialized by SP x S versions of inc along
                //if(it.type == ctool::array_it) {
                if(it.cur_pos >= 0) {

                        tool::move_ref_along(this->ptr, it.ptr,
                                                                        *(it.diff + (pos[it.cur_pos]++)), 1);

                } else {

                        tool::inc_along(*this, it);
                }
        }

        template <bool C, int S, bool P>
        void dec_along_other_dim_at_begin(const subarray_nd_iterator<T, IT, CONST_IT,
                                                REF_IS_ND, C, S, P>& it)
        // 1. other it must be at begin
        // 2. must be of different direction
        {
                //TODO: create specialized by SP x S versions of inc along
                //if(it.type == ctool::array_it) {
                if(it.cur_pos >= 0) {

                        tool::move_ref_along(this->ptr, it.ptr,
                                                                        -*(it.diff + (--pos[it.cur_pos])), 1);

                } else {

                        tool::dec_along(*this, it);
                }
        }

        template <bool C, int S, bool P>
        void move_along(const subarray_nd_iterator<T, IT, CONST_IT,
                                                REF_IS_ND, C, S, P>& it,
                ptrdiff_t j)
        // none of these holds!
        // 1. other it must be at begin
        // 2. must be of different direction
        {
                //TODO: create specialized by SP x S versions of inc along
                //if(it.type == ctool::array_it) {
                if(it.cur_pos >= 0) {

                        if(cur_pos == it.cur_pos) {

                                size_t last = idx[posit];
                                posit += j;
                                diff += j;
                                ptr += step * (idx[posit] - last);

                        } else {

                                size_t& p(pos[it.cur_pos]);
                                ptrdiff_t last = it.idx[p];
                                p += j;
                                tool::move_along(*this, it, it.idx[p] - last);

                        }
                } else {

                        // TODO: ensure this calls the correct offset displacement
                        // for singleton-dim arrays, and if not try to set step
                        // accordingly, to make so.
                        tool::move_along(*this, it, j);
                }
        }

        template <class J>
        inline this_type operator +(const J& j) const
        {
                this_type tmp(*this);
                tmp += j;
                return tmp;
        }

        template <class J>
        inline this_type operator -(const J& j) const
        {
                this_type tmp(*this);
                tmp -= j;
                return tmp;
        }

        template<bool C, int S, bool P>
        ptrdiff_t operator -(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S, P>& it)
        {
                // note: only for itertors of the same dim.
                //TODO: create the specialized versions:
                // 1: for step
                // 2: for array
                // 0: for the following with if:
                if(cur_pos >= 0) {
                        return posit - it.posit;

                } else {

                        return (ptr - it.ptr) / step;
                }
        }

        template<bool C, int S>
        bool operator==(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                        PAST_END_CAPABLE>& it) const
        {
                return (ptr == it.ptr);
        }

        template<bool C, int S>
        bool operator!=(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                        PAST_END_CAPABLE>& it) const
        {
                return (ptr != it.ptr);
        }

        template<bool C, int S>
        bool operator<(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                        PAST_END_CAPABLE>& it) const
        {
                //TODO: specializations
                if(cur_pos >= 0) {
                        return posit < it.posit;

                } else {
                        return (step > 0) ? (ptr < it.ptr) : (it.ptr < ptr);
                }
        }

        template<bool C, int S>
        bool operator<=(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                        PAST_END_CAPABLE>& it) const
        {
                return (*this == it || *this < it);
        }

        template<bool C, int S>
        bool operator>(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                        PAST_END_CAPABLE>& it) const
        {
                return (!(*this == it) && !(*this < it));
        }

        template<bool C, int S>
        bool operator>=(
                const subarray_nd_iterator<T, IT, CONST_IT, REF_IS_ND, C, S,
                        PAST_END_CAPABLE>& it) const
        {
                return (!(*this < it));
        }

};



} /*namespace data */

namespace subarray_iter_create {

template <class IT, class A>
IT _begin(A& a, size_t d)
{
        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        return IT(a.get_iter(j), a.steps[j], 0, (*a.idx)[d].c_ptr(), a.diffs[j],
                k, a.type_from_indtype((*a.idx)[d].indtype),
                a.idx_ar_map.length());
}

template <class IT, class A>
IT _begin(A& a, size_t d, const IT& it)
{
        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        return IT(it.ptr, a.steps[j], it.pos[k < 0 ? 0 : k], (*a.idx)[d].c_ptr(),
                a.diffs[j], k, a.type_from_indtype((*a.idx)[d].indtype), it.pos);
}

template <class IT, class ITS, class A>
IT _iter(A& a, size_t d, const ITS& it)
{
        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        return iterator_nd(it.ir, a.steps[j], it.pos0, (*a.idx)[d].c_ptr(),
                a.diffs[j], k, a.type_from_indtype((*a.idx)[d].indtype), it.pos,
                1, it.get_pos1());

        /*return _begin(d, it);*/
}

template <class IT, class S, class A>
IT _iter(A& a, size_t d, const array<size_t, S>& ind)
{
        typename IT::reference_iterator it = a.iter[-3];

        array<size_t, tiny> pos(a.idx_ar_map.length());
        for(size_t i = 0; i < ind.length(); i++) {
                size_t q = a.idx_ar_rmap[i];
                size_t n = a.nonsing_rmap[i];
                if(q < 0) {
                        A::tool::move_along(it, a.iter[n], a.steps[n], ind[i]);
                } else {
                        A::tool::move_along(it, a.iter[n], a.steps[n], (*a.idx)[i][ind[i]]);
                        pos[q] = ind[i];
                }
        }
        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        return IT(it, a.steps[j], ind[d], (*a.idx)[d].c_ptr(), a.diffs[j],
                k, a.type_from_indtype((*a.idx)[d].indtype), pos);
}

template <class IT, class A>
IT _next(A& a, size_t d, const IT& it)
{
        typename IT::reference_iterator itp = it.ptr;

        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        A::tool::move_along(itp, a.iter[j], 1, a.begin_to_end[j]);

        if(k < 0) // maybe could also be discriminated from indtype
                return IT(itp, a.steps[j], a.sizes[j], (*a.idx)[d].c_ptr(), a.diffs[j],
                        k, a.type_from_indtype((*a.idx)[d].indtype), it.pos);
        else
                return IT(itp, a.steps[j], a.sizes[j], (*a.idx)[d].c_ptr(), a.diffs[j],
                        k, a.type_from_indtype((*a.idx)[d].indtype), it.pos,
                        k, a.sizes[j]);
}

template <class IT, class A>
IT _end(A& a, size_t d)
{
        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        typename IT::reference_iterator it = a.get_iter(j);

        it += a.begin_to_ends[j];

        if(k < 0)
                return IT(it, a.steps[j], a.sizes[j], (*a.idx)[d].c_ptr(), a.diffs[j],
                        k, a.type_from_indtype((*a.idx)[d].indtype),
                                                        a.idx_ar_map.length());
        else
                return IT(it, a.steps[j], a.sizes[j], (*a.idx)[d].c_ptr(), a.diffs[j],
                        k, a.type_from_indtype((*a.idx)[d].indtype),
                        a.idx_ar_map.length(), k, a.sizes[j]);
}

template <class IT, class A>
IT _last(A& a, size_t d)
{
        size_t j = a.nonsing_rmap[d];
        ptrdiff_t k = a.idx_ar_rmap[d]; // cur_pos

        typename IT::reference_iterator it = a.get_iter(j);

        it += a.first_to_lasts[j];

        if(k < 0)
                return IT(it, a.steps[j], a.sizes[j] - 1,
                                                        (*a.idx)[d].c_ptr(), a.diffs[j],
                        k, a.type_from_indtype((*a.idx)[d].indtype),
                                                        a.idx_ar_map.length());
        else
                return IT(it, a.steps[j], a.sizes[j] - 1,
                                                        (*a.idx)[d].c_ptr(), a.diffs[j],
                        k, a.type_from_indtype((*a.idx)[d].indtype),
                        a.idx_ar_map.length(), k, a.sizes[j]);
}

}; // namespace subarray_iter_create

} /*namespace ivl */

#endif // IVL_CORE_DETAILS_ITERATOR_SUBARRAY_ND_ITERATOR_HPP