diff options
| -rw-r--r-- | src/list/operation/higher/take_while.h | 33 | ||||
| -rw-r--r-- | test.cc | 38 |
2 files changed, 70 insertions, 1 deletions
diff --git a/src/list/operation/higher/take_while.h b/src/list/operation/higher/take_while.h new file mode 100644 index 0000000..01062f4 --- /dev/null +++ b/src/list/operation/higher/take_while.h @@ -0,0 +1,33 @@ +#ifndef TYPEASVALUE_SRC_LIST_OPERATION_HIGHER_TAKE_WHILE_H_ +#define TYPEASVALUE_SRC_LIST_OPERATION_HIGHER_TAKE_WHILE_H_ + +#include "type.h" +#include "conditional/if.h" + +namespace tav { + +template < + template<typename> class Predicate, + typename Current +> +struct TakeWhile { + typedef If< + Predicate<Head<Current>>::type::value, + Cons< + Head<Current>, + typename TakeWhile<Predicate, Tail<Current>>::type + >, + void + > type; +}; + +template < + template<typename> class Predicate +> +struct TakeWhile<Predicate, void> { + typedef void type; +}; + +} + +#endif // TYPEASVALUE_SRC_LIST_OPERATION_HIGHER_TAKE_WHILE_H_ @@ -12,6 +12,7 @@ #include "list/operation/higher/partition.h" #include "list/operation/higher/query.h" #include "list/operation/higher/find.h" +#include "list/operation/higher/take_while.h" #include "list/generator/iota.h" #include "list/generator/make_list.h" #include "list/generator/higher/list_tabulate.h" @@ -683,7 +684,7 @@ static_assert( "(count even? (list 1 3 5)) != 0" ); -//list find +// list find static_assert( std::is_same< @@ -718,6 +719,41 @@ static_assert( "(find even? (list 1 3 5)) != #f" ); +// list take while + +static_assert( + std::is_same< + tav::List<tav::Int<2>, tav::Int<4>>::type, + tav::TakeWhile< + tav::Even, + tav::List<tav::Int<2>, tav::Int<4>, tav::Int<5>, tav::Int<6>>::type + >::type + >::value, + "(take-while even? (list 2 4 5 6)) != (list 2 4)" +); + +static_assert( + std::is_same< + tav::List<tav::Int<2>, tav::Int<4>, tav::Int<6>>::type, + tav::TakeWhile< + tav::Even, + tav::List<tav::Int<2>, tav::Int<4>, tav::Int<6>>::type + >::type + >::value, + "(take-while even? (list 2 4 6)) != (list 2 4 6)" +); + +static_assert( + std::is_same< + void, + tav::TakeWhile< + tav::Odd, + tav::List<tav::Int<2>, tav::Int<4>, tav::Int<5>, tav::Int<6>>::type + >::type + >::value, + "(take-while odd? (list 2 4 5 6)) != void" +); + // function apply static_assert( |