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Diffstat (limited to 'sca-cpp/trunk/kernel/list.hpp')
| -rw-r--r-- | sca-cpp/trunk/kernel/list.hpp | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/sca-cpp/trunk/kernel/list.hpp b/sca-cpp/trunk/kernel/list.hpp index 753b33b6a0..e20f3fbd8e 100644 --- a/sca-cpp/trunk/kernel/list.hpp +++ b/sca-cpp/trunk/kernel/list.hpp @@ -523,6 +523,17 @@ template<typename T> inline const T listRef(const list<T>& l, const size_t i) no } /** + * Returns a new list consisting of the first k elements of a list. + */ +template<typename T> inline const list<T> listHead(const list<T>& l, const size_t k) noexcept { + if(k == 0) + return list<T>(); + if(isNull(l)) + return l; + return cons<T>(car(l), listHead(cdr(l), k - 1)); +} + +/** * Returns the tail of a list, ommiting the first k elements. */ template<typename T> inline const list<T> listTail(const list<T>& l, const size_t k) noexcept { |