43 lines
1.1 KiB
C++
43 lines
1.1 KiB
C++
/* @file List.hpp
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*
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* author: Roland Conybeare, Aug 2025
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*/
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#include "Sequence.hpp"
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namespace xo {
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namespace obj {
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/** @class List
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* @brief A list element -- aka cons cell
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**/
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class List : public Sequence {
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public:
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/** the empty list. unique sentinel object **/
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static gp<List> nil;
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/** @return list with first element @p car, and tail @p cdr **/
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static gp<List> cons(gp<Object> car, gp<List> cdr);
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bool is_nil() const { return this == nil.ptr(); }
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gp<Object> head() const { return head_; }
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gp<List> tail() const { return tail_; }
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std::size_t size() const;
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gp<Object> list_ref(std::size_t i) const;
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// inherited from Object..
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virtual std::size_t _shallow_size() const override;
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virtual Object * _shallow_copy() const override;
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virtual std::size_t _forward_children() override;
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private:
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List(gp<Object> head, gp<List> tail);
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private:
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gp<Object> head_;
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gp<List> tail_;
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};
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}
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} /*namespace xo*/
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