mosesdecoder/util/string_piece.hh

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/* If you use ICU in your program, then compile with -DHAVE_ICU -licui18n. If
* you don't use ICU, then this will use the Google implementation from Chrome.
* This has been modified from the original version to let you choose.
*/
// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Copied from strings/stringpiece.h with modifications
//
// A string-like object that points to a sized piece of memory.
//
// Functions or methods may use const StringPiece& parameters to accept either
// a "const char*" or a "string" value that will be implicitly converted to
// a StringPiece. The implicit conversion means that it is often appropriate
// to include this .h file in other files rather than forward-declaring
// StringPiece as would be appropriate for most other Google classes.
//
// Systematic usage of StringPiece is encouraged as it will reduce unnecessary
// conversions from "const char*" to "string" and back again.
//
#ifndef BASE_STRING_PIECE_H__
#define BASE_STRING_PIECE_H__
#include "util/have.hh"
#include <cstring>
#include <iosfwd>
#include <ostream>
#ifdef HAVE_ICU
#include <unicode/stringpiece.h>
#include <unicode/uversion.h>
// Old versions of ICU don't define operator== and operator!=.
#if (U_ICU_VERSION_MAJOR_NUM < 4) || ((U_ICU_VERSION_MAJOR_NUM == 4) && (U_ICU_VERSION_MINOR_NUM < 4))
#warning You are using an old version of ICU. Consider upgrading to ICU >= 4.6.
inline bool operator==(const StringPiece& x, const StringPiece& y) {
if (x.size() != y.size())
return false;
return std::memcmp(x.data(), y.data(), x.size()) == 0;
}
inline bool operator!=(const StringPiece& x, const StringPiece& y) {
return !(x == y);
}
#endif // old version of ICU
U_NAMESPACE_BEGIN
#else
#include <algorithm>
#include <cstddef>
#include <string>
#include <string.h>
#ifdef WIN32
#undef max
#undef min
#endif
class StringPiece {
public:
typedef size_t size_type;
private:
const char* ptr_;
size_type length_;
public:
// We provide non-explicit singleton constructors so users can pass
// in a "const char*" or a "string" wherever a "StringPiece" is
// expected.
StringPiece() : ptr_(NULL), length_(0) { }
StringPiece(const char* str)
: ptr_(str), length_((str == NULL) ? 0 : strlen(str)) { }
StringPiece(const std::string& str)
: ptr_(str.data()), length_(str.size()) { }
StringPiece(const char* offset, size_type len)
: ptr_(offset), length_(len) { }
// data() may return a pointer to a buffer with embedded NULs, and the
// returned buffer may or may not be null terminated. Therefore it is
// typically a mistake to pass data() to a routine that expects a NUL
// terminated string.
const char* data() const { return ptr_; }
size_type size() const { return length_; }
size_type length() const { return length_; }
bool empty() const { return length_ == 0; }
void clear() { ptr_ = NULL; length_ = 0; }
void set(const char* data, size_type len) { ptr_ = data; length_ = len; }
void set(const char* str) {
ptr_ = str;
length_ = str ? strlen(str) : 0;
}
void set(const void* data, size_type len) {
ptr_ = reinterpret_cast<const char*>(data);
length_ = len;
}
char operator[](size_type i) const { return ptr_[i]; }
void remove_prefix(size_type n) {
ptr_ += n;
length_ -= n;
}
void remove_suffix(size_type n) {
length_ -= n;
}
int compare(const StringPiece& x) const {
int r = wordmemcmp(ptr_, x.ptr_, std::min(length_, x.length_));
if (r == 0) {
if (length_ < x.length_) r = -1;
else if (length_ > x.length_) r = +1;
}
return r;
}
std::string as_string() const {
// std::string doesn't like to take a NULL pointer even with a 0 size.
return std::string(!empty() ? data() : "", size());
}
void CopyToString(std::string* target) const;
void AppendToString(std::string* target) const;
// Does "this" start with "x"
bool starts_with(const StringPiece& x) const {
return ((length_ >= x.length_) &&
(wordmemcmp(ptr_, x.ptr_, x.length_) == 0));
}
// Does "this" end with "x"
bool ends_with(const StringPiece& x) const {
return ((length_ >= x.length_) &&
(wordmemcmp(ptr_ + (length_-x.length_), x.ptr_, x.length_) == 0));
}
// standard STL container boilerplate
typedef char value_type;
typedef const char* pointer;
typedef const char& reference;
typedef const char& const_reference;
typedef ptrdiff_t difference_type;
static const size_type npos;
typedef const char* const_iterator;
typedef const char* iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
iterator begin() const { return ptr_; }
iterator end() const { return ptr_ + length_; }
const_reverse_iterator rbegin() const {
return const_reverse_iterator(ptr_ + length_);
}
const_reverse_iterator rend() const {
return const_reverse_iterator(ptr_);
}
size_type max_size() const { return length_; }
size_type capacity() const { return length_; }
size_type copy(char* buf, size_type n, size_type pos = 0) const;
size_type find(const StringPiece& s, size_type pos = 0) const;
size_type find(char c, size_type pos = 0) const;
size_type rfind(const StringPiece& s, size_type pos = npos) const;
size_type rfind(char c, size_type pos = npos) const;
size_type find_first_of(const StringPiece& s, size_type pos = 0) const;
size_type find_first_of(char c, size_type pos = 0) const {
return find(c, pos);
}
size_type find_first_not_of(const StringPiece& s, size_type pos = 0) const;
size_type find_first_not_of(char c, size_type pos = 0) const;
size_type find_last_of(const StringPiece& s, size_type pos = npos) const;
size_type find_last_of(char c, size_type pos = npos) const {
return rfind(c, pos);
}
size_type find_last_not_of(const StringPiece& s, size_type pos = npos) const;
size_type find_last_not_of(char c, size_type pos = npos) const;
StringPiece substr(size_type pos, size_type n = npos) const;
static int wordmemcmp(const char* p, const char* p2, size_type N) {
return memcmp(p, p2, N);
}
};
inline bool operator==(const StringPiece& x, const StringPiece& y) {
if (x.size() != y.size())
return false;
return std::memcmp(x.data(), y.data(), x.size()) == 0;
}
inline bool operator!=(const StringPiece& x, const StringPiece& y) {
return !(x == y);
}
#endif // HAVE_ICU undefined
inline bool operator<(const StringPiece& x, const StringPiece& y) {
const int r = std::memcmp(x.data(), y.data(),
std::min(x.size(), y.size()));
return ((r < 0) || ((r == 0) && (x.size() < y.size())));
}
inline bool operator>(const StringPiece& x, const StringPiece& y) {
return y < x;
}
inline bool operator<=(const StringPiece& x, const StringPiece& y) {
return !(x > y);
}
inline bool operator>=(const StringPiece& x, const StringPiece& y) {
return !(x < y);
}
// allow StringPiece to be logged (needed for unit testing).
inline std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
return o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
}
#ifdef HAVE_ICU
U_NAMESPACE_END
using U_NAMESPACE_QUALIFIER StringPiece;
#endif
#endif // BASE_STRING_PIECE_H__