Re-committing http://codereview.chromium.org/6803005/ after fixing multi-dll build:

third_party/libphonenumber/cpp/src/utf/unicodetext.h

+// Copyright (C) 2006 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Author: Jim Meehan
+
+#ifndef UTIL_UTF8_UNICODETEXT_H__
+#define UTIL_UTF8_UNICODETEXT_H__
+
+#include <iterator>
+#include <string>
+#include <utility>
+#include "base/basictypes.h"
+//#include "util/utf8/public/config.h"
+
+using std::string;
+using std::bidirectional_iterator_tag;
+using std::pair;
+
+// ***************************** UnicodeText **************************
+//
+// A UnicodeText object is a container for a sequence of Unicode
+// codepoint values. It has default, copy, and assignment constructors.
+// Data can be appended to it from another UnicodeText, from
+// iterators, or from a single codepoint.
+//
+// The internal representation of the text is UTF-8. Since UTF-8 is a
+// variable-width format, UnicodeText does not provide random access
+// to the text, and changes to the text are permitted only at the end.
+//
+// The UnicodeText class defines a const_iterator. The dereferencing
+// operator (*) returns a codepoint (char32). The iterator is a
+// bidirectional, read-only iterator. It becomes invalid if the text
+// is changed.
+//
+// There are methods for appending and retrieving UTF-8 data directly.
+// The 'utf8_data' method returns a const char* that contains the
+// UTF-8-encoded version of the text; 'utf8_length' returns the number
+// of bytes in the UTF-8 data. An iterator's 'get' method stores up to
+// 4 bytes of UTF-8 data in a char array and returns the number of
+// bytes that it stored.
+//
+// Codepoints are integers in the range [0, 0xD7FF] or [0xE000,
+// 0x10FFFF], but UnicodeText has the additional restriction that it
+// can contain only those characters that are valid for interchange on
+// the Web. This excludes all of the control codes except for carriage
+// return, line feed, and horizontal tab.  It also excludes
+// non-characters, but codepoints that are in the Private Use regions
+// are allowed, as are codepoints that are unassigned. (See the
+// Unicode reference for details.) The function UniLib::IsInterchangeValid
+// can be used as a test for this property.
+//
+// UnicodeTexts are safe. Every method that constructs or modifies a
+// UnicodeText tests for interchange-validity, and will substitute a
+// space for the invalid data. Such cases are reported via
+// LOG(WARNING).
+//
+// MEMORY MANAGEMENT: copy, take ownership, or point to
+//
+// A UnicodeText is either an "owner", meaning that it owns the memory
+// for the data buffer and will free it when the UnicodeText is
+// destroyed, or it is an "alias", meaning that it does not.
+//
+// There are three methods for storing UTF-8 data in a UnicodeText:
+//
+// CopyUTF8(buffer, len) copies buffer.
+//
+// TakeOwnershipOfUTF8(buffer, size, capacity) takes ownership of buffer.
+//
+// PointToUTF8(buffer, size) creates an alias pointing to buffer.
+//
+// All three methods perform a validity check on the buffer. There are
+// private, "unsafe" versions of these functions that bypass the
+// validity check. They are used internally and by friend-functions
+// that are handling UTF-8 data that has already been validated.
+//
+// The purpose of an alias is to avoid making an unnecessary copy of a
+// UTF-8 buffer while still providing access to the Unicode values
+// within that text through iterators or the fast scanners that are
+// based on UTF-8 state tables. The lifetime of an alias must not
+// exceed the lifetime of the buffer from which it was constructed.
+//
+// The semantics of an alias might be described as "copy on write or
+// repair." The source data is never modified. If push_back() or
+// append() is called on an alias, a copy of the data will be created,
+// and the UnicodeText will become an owner. If clear() is called on
+// an alias, it becomes an (empty) owner.
+//
+// The copy constructor and the assignment operator produce an owner.
+// That is, after direct initialization ("UnicodeText x(y);") or copy
+// initialization ("UnicodeText x = y;") x will be an owner, even if y
+// was an alias. The assignment operator ("x = y;") also produces an
+// owner unless x and y are the same object and y is an alias.
+//
+// Aliases should be used with care. If the source from which an alias
+// was created is freed, or if the contents are changed, while the
+// alias is still in use, fatal errors could result. But it can be
+// quite useful to have a UnicodeText "window" through which to see a
+// UTF-8 buffer without having to pay the price of making a copy.
+//
+// UTILITIES
+//
+// The interfaces in util/utf8/public/textutils.h provide higher-level
+// utilities for dealing with UnicodeTexts, including routines for
+// creating UnicodeTexts (both owners and aliases) from UTF-8 buffers or
+// strings, creating strings from UnicodeTexts, normalizing text for
+// efficient matching or display, and others.
+
+class UnicodeText {
+ public:
+  class const_iterator;
+
+  typedef char32 value_type;
+
+  // Constructors. These always produce owners.
+  UnicodeText();  // Create an empty text.
+  UnicodeText(const UnicodeText& src);  // copy constructor
+  // Construct a substring (copies the data).
+  UnicodeText(const const_iterator& first, const const_iterator& last);
+
+  // Assignment operator. This copies the data and produces an owner
+  // unless this == &src, e.g., "x = x;", which is a no-op.
+  UnicodeText& operator=(const UnicodeText& src);
+
+  // x.Copy(y) copies the data from y into x.
+  UnicodeText& Copy(const UnicodeText& src);
+  inline UnicodeText& assign(const UnicodeText& src) { return Copy(src); }
+
+  // x.PointTo(y) changes x so that it points to y's data.
+  // It does not copy y or take ownership of y's data.
+  UnicodeText& PointTo(const UnicodeText& src);
+  UnicodeText& PointTo(const const_iterator& first,
+                       const const_iterator& last);
+
+  ~UnicodeText();
+
+  void clear();  // Clear text.
+  bool empty() { return repr_.size_ == 0; }  // Test if text is empty.
+
+  // Add a codepoint to the end of the text.
+  // If the codepoint is not interchange-valid, add a space instead
+  // and log a warning.
+  void push_back(char32 codepoint);
+
+  // Generic appending operation.
+  // iterator_traits<ForwardIterator>::value_type must be implicitly
+  // convertible to char32. Typical uses of this method might include:
+  //     char32 chars[] = {0x1, 0x2, ...};
+  //     vector<char32> more_chars = ...;
+  //     utext.append(chars, chars+arraysize(chars));
+  //     utext.append(more_chars.begin(), more_chars.end());
+  template<typename ForwardIterator>
+  UnicodeText& append(ForwardIterator first, const ForwardIterator last) {
+    while (first != last) { push_back(*first++); }
+    return *this;
+  }
+
+  // A specialization of the generic append() method.
+  UnicodeText& append(const const_iterator& first, const const_iterator& last);
+
+  // An optimization of append(source.begin(), source.end()).
+  UnicodeText& append(const UnicodeText& source);
+
+  int size() const;  // the number of Unicode characters (codepoints)
+
+  friend bool operator==(const UnicodeText& lhs, const UnicodeText& rhs);
+  friend bool operator!=(const UnicodeText& lhs, const UnicodeText& rhs);
+
+  class const_iterator {
+    typedef const_iterator CI;
+   public:
+    typedef bidirectional_iterator_tag iterator_category;
+    typedef char32 value_type;
+    typedef ptrdiff_t difference_type;
+    typedef void pointer;  // (Not needed.)
+    typedef const char32 reference;  // (Needed for const_reverse_iterator)
+
+    // Iterators are default-constructible.
+    const_iterator();
+
+    // It's safe to make multiple passes over a UnicodeText.
+    const_iterator(const const_iterator& other);
+    const_iterator& operator=(const const_iterator& other);
+
+    char32 operator*() const;  // Dereference
+
+    const_iterator& operator++();  // Advance (++iter)
+    const_iterator operator++(int) {  // (iter++)
+      const_iterator result(*this);
+      ++*this;
+      return result;
+    }
+
+    const_iterator& operator--();  // Retreat (--iter)
+    const_iterator operator--(int) {  // (iter--)
+      const_iterator result(*this);
+      --*this;
+      return result;
+    }
+
+    // We love relational operators.
+    friend bool operator==(const CI& lhs, const CI& rhs) {
+      return lhs.it_ == rhs.it_; }
+    friend bool operator!=(const CI& lhs, const CI& rhs) {
+      return !(lhs == rhs); }
+    friend bool operator<(const CI& lhs, const CI& rhs);
+    friend bool operator>(const CI& lhs, const CI& rhs) {
+      return rhs < lhs; }
+    friend bool operator<=(const CI& lhs, const CI& rhs) {
+      return !(rhs < lhs); }
+    friend bool operator>=(const CI& lhs, const CI& rhs) {
+      return !(lhs < rhs); }
+
+    friend difference_type distance(const CI& first, const CI& last);
+
+    // UTF-8-specific methods
+    // Store the UTF-8 encoding of the current codepoint into buf,
+    // which must be at least 4 bytes long. Return the number of
+    // bytes written.
+    int get_utf8(char* buf) const;
+    // Return the iterator's pointer into the UTF-8 data.
+    const char* utf8_data() const { return it_; }
+
+    string DebugString() const;
+
+   private:
+    friend class UnicodeText;
+    friend class UnicodeTextUtils;
+    friend class UTF8StateTableProperty;
+    explicit const_iterator(const char* it) : it_(it) {}
+
+    const char* it_;
+  };
+
+  const_iterator begin() const;
+  const_iterator end() const;
+
+  class const_reverse_iterator : public std::reverse_iterator<const_iterator> {
+   public:
+    const_reverse_iterator(const_iterator it) :
+        std::reverse_iterator<const_iterator>(it) {}
+    const char* utf8_data() const {
+      const_iterator tmp_it = base();
+      return (--tmp_it).utf8_data();
+    }
+    int get_utf8(char* buf) const {
+      const_iterator tmp_it = base();
+      return (--tmp_it).get_utf8(buf);
+    }
+  };
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(end());
+  }
+  const_reverse_iterator rend() const {
+    return const_reverse_iterator(begin());
+  }
+
+  // Substring searching.  Returns the beginning of the first
+  // occurrence of "look", or end() if not found.
+  const_iterator find(const UnicodeText& look, const_iterator start_pos) const;
+  // Equivalent to find(look, begin())
+  const_iterator find(const UnicodeText& look) const;
+
+  // Returns whether this contains the character U+FFFD.  This can
+  // occur, for example, if the input to Encodings::Decode() had byte
+  // sequences that were invalid in the source encoding.
+  bool HasReplacementChar() const;
+
+  // UTF-8-specific methods
+  //
+  // Return the data, length, and capacity of UTF-8-encoded version of
+  // the text. Length and capacity are measured in bytes.
+  const char* utf8_data() const { return repr_.data_; }
+  int utf8_length() const { return repr_.size_; }
+  int utf8_capacity() const { return repr_.capacity_; }
+
+  // Return the UTF-8 data as a string.
+  static string UTF8Substring(const const_iterator& first,
+                              const const_iterator& last);
+
+  // There are three methods for initializing a UnicodeText from UTF-8
+  // data. They vary in details of memory management. In all cases,
+  // the data is tested for interchange-validity. If it is not
+  // interchange-valid, a LOG(WARNING) is issued, and each
+  // structurally invalid byte and each interchange-invalid codepoint
+  // is replaced with a space.
+
+  // x.CopyUTF8(buf, len) copies buf into x.
+  UnicodeText& CopyUTF8(const char* utf8_buffer, int byte_length);
+
+  // x.TakeOwnershipOfUTF8(buf, len, capacity). x takes ownership of
+  // buf. buf is not copied.
+  UnicodeText& TakeOwnershipOfUTF8(char* utf8_buffer,
+                                   int byte_length,
+                                   int byte_capacity);
+
+  // x.PointToUTF8(buf,len) changes x so that it points to buf
+  // ("becomes an alias"). It does not take ownership or copy buf.
+  // If the buffer is not valid, this has the same effect as
+  // CopyUTF8(utf8_buffer, byte_length).
+  UnicodeText& PointToUTF8(const char* utf8_buffer, int byte_length);
+
+  // Occasionally it is necessary to use functions that operate on the
+  // pointer returned by utf8_data(). MakeIterator(p) provides a way
+  // to get back to the UnicodeText level. It uses CHECK to ensure
+  // that p is a pointer within this object's UTF-8 data, and that it
+  // points to the beginning of a character.
+  const_iterator MakeIterator(const char* p) const;
+
+  string DebugString() const;
+
+ private:
+  friend class const_iterator;
+  friend class UnicodeTextUtils;
+
+  class Repr {  // A byte-string.
+   public:
+    char* data_;
+    int size_;
+    int capacity_;
+    bool ours_;  // Do we own data_?
+
+    Repr() : data_(NULL), size_(0), capacity_(0), ours_(true) {}
+    ~Repr() { if (ours_) delete[] data_; }
+
+    void clear();
+    void reserve(int capacity);
+    void resize(int size);
+
+    void append(const char* bytes, int byte_length);
+    void Copy(const char* data, int size);
+    void TakeOwnershipOf(char* data, int size, int capacity);
+    void PointTo(const char* data, int size);
+
+    string DebugString() const;
+
+   private:
+    Repr& operator=(const Repr&);
+    Repr(const Repr& other);
+  };
+
+  Repr repr_;
+
+  // UTF-8-specific private methods.
+  // These routines do not perform a validity check when compiled
+  // in opt mode.
+  // It is an error to call these methods with UTF-8 data that
+  // is not interchange-valid.
+  //
+  UnicodeText& UnsafeCopyUTF8(const char* utf8_buffer, int byte_length);
+  UnicodeText& UnsafeTakeOwnershipOfUTF8(
+      char* utf8_buffer, int byte_length, int byte_capacity);
+  UnicodeText& UnsafePointToUTF8(const char* utf8_buffer, int byte_length);
+  UnicodeText& UnsafeAppendUTF8(const char* utf8_buffer, int byte_length);
+  const_iterator UnsafeFind(const UnicodeText& look,
+                            const_iterator start_pos) const;
+};
+
+bool operator==(const UnicodeText& lhs, const UnicodeText& rhs);
+
+inline bool operator!=(const UnicodeText& lhs, const UnicodeText& rhs) {
+  return !(lhs == rhs);
+}
+
+// UnicodeTextRange is a pair of iterators, useful for specifying text
+// segments. If the iterators are ==, the segment is empty.
+typedef pair<UnicodeText::const_iterator,
+             UnicodeText::const_iterator> UnicodeTextRange;
+
+inline bool UnicodeTextRangeIsEmpty(const UnicodeTextRange& r) {
+  return r.first == r.second;
+}
+
+
+// *************************** Utilities *************************
+
+// A factory function for creating a UnicodeText from a buffer of
+// UTF-8 data. The new UnicodeText takes ownership of the buffer. (It
+// is an "owner.")
+//
+// Each byte that is structurally invalid will be replaced with a
+// space. Each codepoint that is interchange-invalid will also be
+// replaced with a space, even if the codepoint was represented with a
+// multibyte sequence in the UTF-8 data.
+//
+inline UnicodeText MakeUnicodeTextAcceptingOwnership(
+    char* utf8_buffer, int byte_length, int byte_capacity) {
+  return UnicodeText().TakeOwnershipOfUTF8(
+      utf8_buffer, byte_length, byte_capacity);
+}
+
+// A factory function for creating a UnicodeText from a buffer of
+// UTF-8 data. The new UnicodeText does not take ownership of the
+// buffer. (It is an "alias.")
+//
+inline UnicodeText MakeUnicodeTextWithoutAcceptingOwnership(
+    const char* utf8_buffer, int byte_length) {
+  return UnicodeText().PointToUTF8(utf8_buffer, byte_length);
+}
+
+// Create a UnicodeText from a UTF-8 string or buffer.
+//
+// If do_copy is true, then a copy of the string is made. The copy is
+// owned by the resulting UnicodeText object and will be freed when
+// the object is destroyed. This UnicodeText object is referred to
+// as an "owner."
+//
+// If do_copy is false, then no copy is made. The resulting
+// UnicodeText object does NOT take ownership of the string; in this
+// case, the lifetime of the UnicodeText object must not exceed the
+// lifetime of the string. This Unicodetext object is referred to as
+// an "alias." This is the same as MakeUnicodeTextWithoutAcceptingOwnership.
+//
+// If the input string does not contain valid UTF-8, then a copy is
+// made (as if do_copy were true) and coerced to valid UTF-8 by
+// replacing each invalid byte with a space.
+//
+inline UnicodeText UTF8ToUnicodeText(const char* utf8_buf, int len,
+                                     bool do_copy) {
+  UnicodeText t;
+  if (do_copy) {
+    t.CopyUTF8(utf8_buf, len);
+  } else {
+    t.PointToUTF8(utf8_buf, len);
+  }
+  return t;
+}
+
+inline UnicodeText UTF8ToUnicodeText(const string& utf_string, bool do_copy) {
+  return UTF8ToUnicodeText(utf_string.data(), utf_string.size(), do_copy);
+}
+
+inline UnicodeText UTF8ToUnicodeText(const char* utf8_buf, int len) {
+  return UTF8ToUnicodeText(utf8_buf, len, true);
+}
+inline UnicodeText UTF8ToUnicodeText(const string& utf8_string) {
+  return UTF8ToUnicodeText(utf8_string, true);
+}
+
+// Return a string containing the UTF-8 encoded version of all the
+// Unicode characters in t.
+inline string UnicodeTextToUTF8(const UnicodeText& t) {
+  return string(t.utf8_data(), t.utf8_length());
+}
+
+#endif  // UTIL_UTF8_UNICODETEXT_H__