1 // -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; tab-width: 8 -*-
2 //
3 // self_match.h: Rcpp R/C++ interface class library -- self match
4 //
5 // Copyright (C) 2012 Dirk Eddelbuettel and Romain Francois
6 //
7 // This file is part of Rcpp.
8 //
9 // Rcpp is free software: you can redistribute it and/or modify it
10 // under the terms of the GNU General Public License as published by
11 // the Free Software Foundation, either version 2 of the License, or
12 // (at your option) any later version.
13 //
14 // Rcpp is distributed in the hope that it will be useful, but
15 // WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
18 //
19 // You should have received a copy of the GNU General Public License
20 // along with Rcpp. If not, see <http://www.gnu.org/licenses/>.
21
22 #ifndef Rcpp__sugar__self_match_h
23 #define Rcpp__sugar__self_match_h
24
25 namespace Rcpp{
26 namespace sugar{
27
28 template <typename HASH, typename STORAGE>
29 class SelfInserter {
30 public:
SelfInserter(HASH & hash_)31 SelfInserter( HASH& hash_ ) : hash(hash_), index(0) {}
32
operator()33 inline R_xlen_t operator()( STORAGE value ){
34 typename HASH::iterator it = hash.find( value ) ;
35 if( it == hash.end() ){
36 hash.insert( std::make_pair(value, ++index) ) ;
37 return index ;
38 } else {
39 return it->second ;
40 }
41 }
42
43 private:
44 HASH& hash ;
45 R_xlen_t index;
46 } ;
47
48 template <int RTYPE, typename TABLE_T>
49 class SelfMatch {
50 public:
51 typedef typename Rcpp::traits::storage_type<RTYPE>::type STORAGE ;
52
SelfMatch(const TABLE_T & table)53 SelfMatch( const TABLE_T& table ): hash(), result(table.size()) {
54 std::transform( table.begin(), table.end(), result.begin(), Inserter(hash) ) ;
55 }
56
IntegerVector()57 inline operator IntegerVector() const { return result ; }
58
59 private:
60 typedef RCPP_UNORDERED_MAP<STORAGE, int> HASH ;
61 typedef SelfInserter<HASH,STORAGE> Inserter ;
62 HASH hash ;
63 IntegerVector result ;
64 };
65
66 } // sugar
67
68 template <int RTYPE, bool NA, typename T>
self_match(const VectorBase<RTYPE,NA,T> & x)69 inline IntegerVector self_match( const VectorBase<RTYPE,NA,T>& x ){
70 Vector<RTYPE> vec(x) ;
71 return sugar::SelfHash<RTYPE>(vec).fill_and_self_match() ;
72 }
73
74
75 } // Rcpp
76 #endif
77
78