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      1 /*
      2  * Copyright (C) 2010, Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1.  Redistributions of source code must retain the above copyright
      8  *     notice, this list of conditions and the following disclaimer.
      9  * 2.  Redistributions in binary form must reproduce the above copyright
     10  *     notice, this list of conditions and the following disclaimer in the
     11  *     documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
     20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     23  */
     24 
     25 #ifndef TextPosition_h
     26 #define TextPosition_h
     27 
     28 #include "wtf/Assertions.h"
     29 #include "wtf/Vector.h"
     30 #include "wtf/WTFExport.h"
     31 #include "wtf/text/WTFString.h"
     32 
     33 namespace WTF {
     34 
     35 // An abstract number of element in a sequence. The sequence has a first element.
     36 // This type should be used instead of integer because 2 contradicting traditions can
     37 // call a first element '0' or '1' which makes integer type ambiguous.
     38 class OrdinalNumber {
     39 public:
     40     static OrdinalNumber fromZeroBasedInt(int zeroBasedInt) { return OrdinalNumber(zeroBasedInt); }
     41     static OrdinalNumber fromOneBasedInt(int oneBasedInt) { return OrdinalNumber(oneBasedInt - 1); }
     42     OrdinalNumber() : m_zeroBasedValue(0) { }
     43 
     44     int zeroBasedInt() const { return m_zeroBasedValue; }
     45     int oneBasedInt() const { return m_zeroBasedValue + 1; }
     46 
     47     bool operator==(OrdinalNumber other) { return m_zeroBasedValue == other.m_zeroBasedValue; }
     48     bool operator!=(OrdinalNumber other) { return !((*this) == other); }
     49 
     50     static OrdinalNumber first() { return OrdinalNumber(0); }
     51     static OrdinalNumber beforeFirst() { return OrdinalNumber(-1); }
     52 
     53 private:
     54     OrdinalNumber(int zeroBasedInt) : m_zeroBasedValue(zeroBasedInt) { }
     55     int m_zeroBasedValue;
     56 };
     57 
     58 
     59 // TextPosition structure specifies coordinates within an text resource. It is used mostly
     60 // for saving script source position.
     61 class TextPosition {
     62 public:
     63     TextPosition(OrdinalNumber line, OrdinalNumber column)
     64         : m_line(line)
     65         , m_column(column)
     66     {
     67     }
     68     TextPosition() { }
     69     bool operator==(const TextPosition& other) { return m_line == other.m_line && m_column == other.m_column; }
     70     bool operator!=(const TextPosition& other) { return !((*this) == other); }
     71     WTF_EXPORT OrdinalNumber toOffset(const Vector<unsigned>&);
     72 
     73     // A 'minimum' value of position, used as a default value.
     74     static TextPosition minimumPosition() { return TextPosition(OrdinalNumber::first(), OrdinalNumber::first()); }
     75 
     76     // A value with line value less than a minimum; used as an impossible position.
     77     static TextPosition belowRangePosition() { return TextPosition(OrdinalNumber::beforeFirst(), OrdinalNumber::beforeFirst()); }
     78 
     79     // A value corresponding to a position with given offset within text having the specified line ending offsets.
     80     WTF_EXPORT static TextPosition fromOffsetAndLineEndings(unsigned, const Vector<unsigned>&);
     81 
     82     OrdinalNumber m_line;
     83     OrdinalNumber m_column;
     84 };
     85 
     86 WTF_EXPORT PassOwnPtr<Vector<unsigned> > lineEndings(const String&);
     87 
     88 } // namespace WTF
     89 
     90 using WTF::OrdinalNumber;
     91 
     92 using WTF::TextPosition;
     93 
     94 using WTF::lineEndings;
     95 
     96 #endif // TextPosition_h
     97