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Diffstat (limited to 'butl/prefix-map')
-rw-r--r-- | butl/prefix-map | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/butl/prefix-map b/butl/prefix-map deleted file mode 100644 index b350752..0000000 --- a/butl/prefix-map +++ /dev/null @@ -1,138 +0,0 @@ -// file : butl/prefix-map -*- C++ -*- -// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd -// license : MIT; see accompanying LICENSE file - -#ifndef BUTL_PREFIX_MAP -#define BUTL_PREFIX_MAP - -#include <map> -#include <string> -#include <utility> // move() -#include <algorithm> // min() - -namespace butl -{ - // A map of hierarchical "paths", e.g., 'foo.bar' or 'foo/bar' with - // the ability to retrieve a range of entries that have a specific - // prefix. The '.' and '/' above are the delimiter characters. - // - // Note that as a special rule, the default implementation of - // compare_prefix treats empty key as everyone's prefix even if - // the paths don't start with the delimiter (useful to represent - // a "root path"). - // - // Implementation-wise, the idea is to pretend that each key ends - // with the delimiter. This way we automatically avoid matching - // 'foobar' as having a prefix 'foo'. - // - template <typename K> - struct compare_prefix; - - template <typename C> - struct compare_prefix<std::basic_string<C>> - { - typedef std::basic_string<C> K; - - typedef C delimiter_type; - typedef typename K::size_type size_type; - typedef typename K::traits_type traits_type; - - explicit - compare_prefix (delimiter_type d): d_ (d) {} - - bool - operator() (const K& x, const K& y) const - { - return compare (x.c_str (), x.size (), y.c_str (), y.size ()) < 0; - } - - bool - prefix (const K& p, const K& k) const - { - size_type pn (p.size ()), kn (k.size ()); - return pn == 0 || // Empty key is always a prefix. - (pn <= kn && - compare (p.c_str (), pn, k.c_str (), pn == kn ? pn : pn + 1) == 0); - } - - protected: - int - compare (const C* x, size_type xn, - const C* y, size_type yn) const - { - size_type n (std::min (xn, yn)); - int r (traits_type::compare (x, y, n)); - - if (r == 0) - { - // Pretend there is the delimiter characters at the end of the - // shorter string. - // - char xc (xn > n ? x[n] : (xn++, d_)); - char yc (yn > n ? y[n] : (yn++, d_)); - r = traits_type::compare (&xc, &yc, 1); - - // If we are still equal, then compare the lengths. - // - if (r == 0) - r = (xn == yn ? 0 : (xn < yn ? -1 : 1)); - } - - return r; - } - - private: - delimiter_type d_; - }; - - template <typename M> - struct prefix_map_common: M - { - typedef M map_type; - typedef typename map_type::key_type key_type; - typedef typename map_type::value_type value_type; - typedef typename map_type::key_compare compare_type; - typedef typename compare_type::delimiter_type delimiter_type; - - typedef typename map_type::iterator iterator; - typedef typename map_type::const_iterator const_iterator; - - explicit - prefix_map_common (delimiter_type d) - : map_type (compare_type (d)) {} - - prefix_map_common (std::initializer_list<value_type> i, delimiter_type d) - : map_type (std::move (i), compare_type (d)) {} - - std::pair<iterator, iterator> - find_prefix (const key_type&); - - std::pair<const_iterator, const_iterator> - find_prefix (const key_type&) const; - }; - - template <typename M, typename prefix_map_common<M>::delimiter_type D> - struct prefix_map_impl: prefix_map_common<M> - { - typedef typename prefix_map_common<M>::value_type value_type; - - prefix_map_impl (): prefix_map_common<M> (D) {} - prefix_map_impl (std::initializer_list<value_type> i) - : prefix_map_common<M> (std::move (i), D) {} - }; - - template <typename K, - typename T, - typename compare_prefix<K>::delimiter_type D> - using prefix_map = prefix_map_impl<std::map<K, T, compare_prefix<K>>, D>; - - template <typename K, - typename T, - typename compare_prefix<K>::delimiter_type D> - using prefix_multimap = - prefix_map_impl<std::multimap<K, T, compare_prefix<K>>, D>; -} - -#include <butl/prefix-map.txx> - -#endif // BUTL_PREFIX_MAP |