Filtering

Functions
template<typename P >
impl::take_while< P >	rangeless::fn::take_while (P pred)
	Yield elements until pred evaluates to false. More...
impl::take_while< impl::call_count_lt >	rangeless::fn::take_first (size_t n=1)
	Yield first n elements. More...
impl::take_last	rangeless::fn::take_last (size_t n=1)
	Yield last n elements. More...
template<typename P >
impl::drop_while< P >	rangeless::fn::drop_while (P pred)
	Drop elements until pred evaluates to false. More...
impl::drop_while< impl::call_count_lt >	rangeless::fn::drop_first (size_t n=1)
	Drop first n elements. More...
impl::drop_last	rangeless::fn::drop_last (size_t n=1)
	Drop last n elements. More...
template<typename P >
impl::where< P >	rangeless::fn::where (P pred)
	Filter elements. More...
template<typename SortedForwardRange , typename F >
impl::where< impl::in_sorted_by< SortedForwardRange, F > >	rangeless::fn::where_in_sorted_by (const SortedForwardRange &r, F key_fn)
template<typename SortedForwardRange >
impl::where< impl::in_sorted_by< SortedForwardRange, by::identity > >	rangeless::fn::where_in_sorted (const SortedForwardRange &r)
	Intersect with a sorted range. More...
template<typename SortedForwardRange , typename F >
impl::where< impl::in_sorted_by< SortedForwardRange, F > >	rangeless::fn::where_not_in_sorted_by (const SortedForwardRange &r, F key_fn)
template<typename SortedForwardRange >
impl::where< impl::in_sorted_by< SortedForwardRange, by::identity > >	rangeless::fn::where_not_in_sorted (const SortedForwardRange &r)
	Subtract a sorted range. More...
template<typename F >
impl::where_max_by< F >	rangeless::fn::where_max_by (F key_fn)
	Filter elements to those having maximum value of fn. More...
impl::where_max_by< by::identity >	rangeless::fn::where_max ()
template<typename F >
impl::where_max_by< F >	rangeless::fn::where_min_by (F key_fn)
impl::where_max_by< by::identity >	rangeless::fn::where_min ()
template<typename Pred >
impl::exists_where< Pred >	rangeless::fn::exists_where (Pred p)

Detailed Description

Function Documentation

drop_first()

impl::drop_while<impl::call_count_lt> rangeless::fn::drop_first ( size_t  n = 1 )

inline

Drop first n elements.

Definition at line 3859 of file fn.hpp.

drop_last()

impl::drop_last rangeless::fn::drop_last ( size_t  n = 1 )

inline

Drop last n elements.

Buffering space requirements for seq: O(n).

Definition at line 3867 of file fn.hpp.

drop_while()

template<typename P >

impl::drop_while<P> rangeless::fn::drop_while

(

P

pred

)

Drop elements until pred evaluates to false.

Definition at line 3853 of file fn.hpp.

exists_where()

template<typename Pred >

impl::exists_where<Pred> rangeless::fn::exists_where

(

Pred

p

)

const bool any  = vals %  fn::exists_where(pred);
const bool none = vals % !fn::exists_where(pred);
const bool all =  vals % !fn::exists_where(not_pred);

Definition at line 3997 of file fn.hpp.

take_first()

impl::take_while<impl::call_count_lt> rangeless::fn::take_first ( size_t  n = 1 )

inline

Yield first n elements.

Definition at line 3838 of file fn.hpp.

take_last()

impl::take_last rangeless::fn::take_last ( size_t  n = 1 )

inline

Yield last n elements.

Buffering space requirements for seq: O(n).

Definition at line 3846 of file fn.hpp.

take_while()

template<typename P >

impl::take_while<P> rangeless::fn::take_while

(

P

pred

)

Yield elements until pred evaluates to false.

Definition at line 3832 of file fn.hpp.

where()

template<typename P >

impl::where<P> rangeless::fn::where

(

P

pred

)

Filter elements.

Returns a unary function-object.

// 1) If arg is a container passed by lvalue-reference,
// return a copy of the container with elements 
// satisfying the predicate:
auto nonempty_strs = strs % fn::where([](auto&& s) { return !s.empty(); });

// 2.1) If arg is a sequence container passed by rvalue,
// remove the unsatisfying elements using erase-remove idiom and return the container.
//
// 2.2) If arg is a container having equal_range method (sets, associative containers, etc),
// remove the unsatisfying elements using iterate-erase idiom and return the container.
strs = std::move(strs) % fn::where([](auto&& s) { return !s.empty(); });

// 3) If arg is a seq<G>, return adapted seq<...> that shall 
// yield elements satisfying the predicate:
auto res = fn::seq([i = 0]
{
    return i < 5 ? i++ : fn::end_seq();

}) % fn::where(     [](int x) { return x > 2; }) // 3, 4
   % fn::transform( [](int x) { return x + 1; }) // 4, 5
   % fn::foldl_d(   [](int out, int in) { return out*10 + in; });
VERIFY(res == 45);

Definition at line 3903 of file fn.hpp.

where_in_sorted()

template<typename SortedForwardRange >

impl::where<impl::in_sorted_by<SortedForwardRange, by::identity> > rangeless::fn::where_in_sorted

(

const SortedForwardRange &

r

)

Intersect with a sorted range.

elems %= fn::where_in_sorted(whitelist);

Definition at line 3920 of file fn.hpp.

where_in_sorted_by()

template<typename SortedForwardRange , typename F >

impl::where<impl::in_sorted_by<SortedForwardRange, F> > rangeless::fn::where_in_sorted_by	(	const SortedForwardRange &	r,
		F	key_fn
	)

See also

where_in_sorted

Definition at line 3910 of file fn.hpp.

where_max()

impl::where_max_by<by::identity> rangeless::fn::where_max ( )

inline

Definition at line 3973 of file fn.hpp.

where_max_by()

template<typename F >

impl::where_max_by<F> rangeless::fn::where_max_by

(

F

key_fn

)

Filter elements to those having maximum value of fn.

// 1) If Arg is a container (taken by value), find the max-element
// and return a vector of max-elements (moved-from the original container).
strs = std::move(strs) % fn::where_max_by([](auto&& s) { return s.size(); });

// 2) If Arg is a seq, iterates the seq and returns
// std::vector<seq<...>::value_type> containing maximal elements.
auto res = fn::seq([i = 0]
{
    return i < 5 ? i++ : fn::end_seq();
}) % fn::where_max_by([](int x) { return x % 2; });
VERIFY((res == vec_t{{1, 3}}));

Buffering space requirements for seq: O(k), where k = maximum number of max-elements in a prefix of seq over all prefixes of seq. e.g.
[1,0,1,1,0,1,1,9]: k = 5
[1,3,1,1,3,1,1,9]: k = 2

Definition at line 3968 of file fn.hpp.

where_min()

impl::where_max_by<by::identity> rangeless::fn::where_min ( )

inline

Definition at line 3986 of file fn.hpp.

where_min_by()

template<typename F >

impl::where_max_by<F> rangeless::fn::where_min_by

(

F

key_fn

)

Filter elements to those having maximum value of fn.

See also

where_max_by

Definition at line 3981 of file fn.hpp.

where_not_in_sorted()

template<typename SortedForwardRange >

impl::where<impl::in_sorted_by<SortedForwardRange, by::identity> > rangeless::fn::where_not_in_sorted

(

const SortedForwardRange &

r

)

Subtract a sorted range.

elems %= fn::where_not_in_sorted(blacklist);

Definition at line 3937 of file fn.hpp.

where_not_in_sorted_by()

template<typename SortedForwardRange , typename F >

impl::where<impl::in_sorted_by<SortedForwardRange, F> > rangeless::fn::where_not_in_sorted_by	(	const SortedForwardRange &	r,
		F	key_fn
	)

See also

where_not_in_sorted

Definition at line 3927 of file fn.hpp.