1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/string/public/nsStringIterator.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,327 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsStringIterator_h___
1.10 +#define nsStringIterator_h___
1.11 +
1.12 +#include "nsCharTraits.h"
1.13 +#include "nsAlgorithm.h"
1.14 +#include "nsDebug.h"
1.15 +
1.16 + /**
1.17 + * @see nsTAString
1.18 + */
1.19 +
1.20 +template <class CharT>
1.21 +class nsReadingIterator
1.22 + {
1.23 + public:
1.24 + typedef nsReadingIterator<CharT> self_type;
1.25 + typedef ptrdiff_t difference_type;
1.26 + typedef CharT value_type;
1.27 + typedef const CharT* pointer;
1.28 + typedef const CharT& reference;
1.29 +
1.30 + private:
1.31 + friend class nsAString;
1.32 + friend class nsACString;
1.33 +
1.34 + // unfortunately, the API for nsReadingIterator requires that the
1.35 + // iterator know its start and end positions. this was needed when
1.36 + // we supported multi-fragment strings, but now it is really just
1.37 + // extra baggage. we should remove mStart and mEnd at some point.
1.38 +
1.39 + const CharT* mStart;
1.40 + const CharT* mEnd;
1.41 + const CharT* mPosition;
1.42 +
1.43 + public:
1.44 + nsReadingIterator() { }
1.45 + // nsReadingIterator( const nsReadingIterator<CharT>& ); // auto-generated copy-constructor OK
1.46 + // nsReadingIterator<CharT>& operator=( const nsReadingIterator<CharT>& ); // auto-generated copy-assignment operator OK
1.47 +
1.48 + inline void normalize_forward() {}
1.49 + inline void normalize_backward() {}
1.50 +
1.51 + pointer
1.52 + start() const
1.53 + {
1.54 + return mStart;
1.55 + }
1.56 +
1.57 + pointer
1.58 + end() const
1.59 + {
1.60 + return mEnd;
1.61 + }
1.62 +
1.63 + pointer
1.64 + get() const
1.65 + {
1.66 + return mPosition;
1.67 + }
1.68 +
1.69 + CharT
1.70 + operator*() const
1.71 + {
1.72 + return *get();
1.73 + }
1.74 +
1.75 +#if 0
1.76 + // An iterator really deserves this, but some compilers (notably IBM VisualAge for OS/2)
1.77 + // don't like this when |CharT| is a type without members.
1.78 + pointer
1.79 + operator->() const
1.80 + {
1.81 + return get();
1.82 + }
1.83 +#endif
1.84 +
1.85 + self_type&
1.86 + operator++()
1.87 + {
1.88 + ++mPosition;
1.89 + return *this;
1.90 + }
1.91 +
1.92 + self_type
1.93 + operator++( int )
1.94 + {
1.95 + self_type result(*this);
1.96 + ++mPosition;
1.97 + return result;
1.98 + }
1.99 +
1.100 + self_type&
1.101 + operator--()
1.102 + {
1.103 + --mPosition;
1.104 + return *this;
1.105 + }
1.106 +
1.107 + self_type
1.108 + operator--( int )
1.109 + {
1.110 + self_type result(*this);
1.111 + --mPosition;
1.112 + return result;
1.113 + }
1.114 +
1.115 + difference_type
1.116 + size_forward() const
1.117 + {
1.118 + return mEnd - mPosition;
1.119 + }
1.120 +
1.121 + difference_type
1.122 + size_backward() const
1.123 + {
1.124 + return mPosition - mStart;
1.125 + }
1.126 +
1.127 + self_type&
1.128 + advance( difference_type n )
1.129 + {
1.130 + if (n > 0)
1.131 + {
1.132 + difference_type step = XPCOM_MIN(n, size_forward());
1.133 +
1.134 + NS_ASSERTION(step>0, "can't advance a reading iterator beyond the end of a string");
1.135 +
1.136 + mPosition += step;
1.137 + }
1.138 + else if (n < 0)
1.139 + {
1.140 + difference_type step = XPCOM_MAX(n, -size_backward());
1.141 +
1.142 + NS_ASSERTION(step<0, "can't advance (backward) a reading iterator beyond the end of a string");
1.143 +
1.144 + mPosition += step;
1.145 + }
1.146 + return *this;
1.147 + }
1.148 + };
1.149 +
1.150 + /**
1.151 + * @see nsTAString
1.152 + */
1.153 +
1.154 +template <class CharT>
1.155 +class nsWritingIterator
1.156 + {
1.157 + public:
1.158 + typedef nsWritingIterator<CharT> self_type;
1.159 + typedef ptrdiff_t difference_type;
1.160 + typedef CharT value_type;
1.161 + typedef CharT* pointer;
1.162 + typedef CharT& reference;
1.163 +
1.164 + private:
1.165 + friend class nsAString;
1.166 + friend class nsACString;
1.167 +
1.168 + // unfortunately, the API for nsWritingIterator requires that the
1.169 + // iterator know its start and end positions. this was needed when
1.170 + // we supported multi-fragment strings, but now it is really just
1.171 + // extra baggage. we should remove mStart and mEnd at some point.
1.172 +
1.173 + CharT* mStart;
1.174 + CharT* mEnd;
1.175 + CharT* mPosition;
1.176 +
1.177 + public:
1.178 + nsWritingIterator() { }
1.179 + // nsWritingIterator( const nsWritingIterator<CharT>& ); // auto-generated copy-constructor OK
1.180 + // nsWritingIterator<CharT>& operator=( const nsWritingIterator<CharT>& ); // auto-generated copy-assignment operator OK
1.181 +
1.182 + inline void normalize_forward() {}
1.183 + inline void normalize_backward() {}
1.184 +
1.185 + pointer
1.186 + start() const
1.187 + {
1.188 + return mStart;
1.189 + }
1.190 +
1.191 + pointer
1.192 + end() const
1.193 + {
1.194 + return mEnd;
1.195 + }
1.196 +
1.197 + pointer
1.198 + get() const
1.199 + {
1.200 + return mPosition;
1.201 + }
1.202 +
1.203 + reference
1.204 + operator*() const
1.205 + {
1.206 + return *get();
1.207 + }
1.208 +
1.209 +#if 0
1.210 + // An iterator really deserves this, but some compilers (notably IBM VisualAge for OS/2)
1.211 + // don't like this when |CharT| is a type without members.
1.212 + pointer
1.213 + operator->() const
1.214 + {
1.215 + return get();
1.216 + }
1.217 +#endif
1.218 +
1.219 + self_type&
1.220 + operator++()
1.221 + {
1.222 + ++mPosition;
1.223 + return *this;
1.224 + }
1.225 +
1.226 + self_type
1.227 + operator++( int )
1.228 + {
1.229 + self_type result(*this);
1.230 + ++mPosition;
1.231 + return result;
1.232 + }
1.233 +
1.234 + self_type&
1.235 + operator--()
1.236 + {
1.237 + --mPosition;
1.238 + return *this;
1.239 + }
1.240 +
1.241 + self_type
1.242 + operator--( int )
1.243 + {
1.244 + self_type result(*this);
1.245 + --mPosition;
1.246 + return result;
1.247 + }
1.248 +
1.249 + difference_type
1.250 + size_forward() const
1.251 + {
1.252 + return mEnd - mPosition;
1.253 + }
1.254 +
1.255 + difference_type
1.256 + size_backward() const
1.257 + {
1.258 + return mPosition - mStart;
1.259 + }
1.260 +
1.261 + self_type&
1.262 + advance( difference_type n )
1.263 + {
1.264 + if (n > 0)
1.265 + {
1.266 + difference_type step = XPCOM_MIN(n, size_forward());
1.267 +
1.268 + NS_ASSERTION(step>0, "can't advance a writing iterator beyond the end of a string");
1.269 +
1.270 + mPosition += step;
1.271 + }
1.272 + else if (n < 0)
1.273 + {
1.274 + difference_type step = XPCOM_MAX(n, -size_backward());
1.275 +
1.276 + NS_ASSERTION(step<0, "can't advance (backward) a writing iterator beyond the end of a string");
1.277 +
1.278 + mPosition += step;
1.279 + }
1.280 + return *this;
1.281 + }
1.282 +
1.283 + void
1.284 + write( const value_type* s, uint32_t n )
1.285 + {
1.286 + NS_ASSERTION(size_forward() > 0, "You can't |write| into an |nsWritingIterator| with no space!");
1.287 +
1.288 + nsCharTraits<value_type>::move(mPosition, s, n);
1.289 + advance( difference_type(n) );
1.290 + }
1.291 + };
1.292 +
1.293 +template <class CharT>
1.294 +inline
1.295 +bool
1.296 +operator==( const nsReadingIterator<CharT>& lhs, const nsReadingIterator<CharT>& rhs )
1.297 + {
1.298 + return lhs.get() == rhs.get();
1.299 + }
1.300 +
1.301 +template <class CharT>
1.302 +inline
1.303 +bool
1.304 +operator!=( const nsReadingIterator<CharT>& lhs, const nsReadingIterator<CharT>& rhs )
1.305 + {
1.306 + return lhs.get() != rhs.get();
1.307 + }
1.308 +
1.309 +
1.310 + //
1.311 + // |nsWritingIterator|s
1.312 + //
1.313 +
1.314 +template <class CharT>
1.315 +inline
1.316 +bool
1.317 +operator==( const nsWritingIterator<CharT>& lhs, const nsWritingIterator<CharT>& rhs )
1.318 + {
1.319 + return lhs.get() == rhs.get();
1.320 + }
1.321 +
1.322 +template <class CharT>
1.323 +inline
1.324 +bool
1.325 +operator!=( const nsWritingIterator<CharT>& lhs, const nsWritingIterator<CharT>& rhs )
1.326 + {
1.327 + return lhs.get() != rhs.get();
1.328 + }
1.329 +
1.330 +#endif /* !defined(nsStringIterator_h___) */
