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
33namespace 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.
38class OrdinalNumber {
39public:
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
53private:
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.
61class TextPosition {
62public:
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
86WTF_EXPORT PassOwnPtr<Vector<unsigned> > lineEndings(const String&);
87
88} // namespace WTF
89
90using WTF::OrdinalNumber;
91
92using WTF::TextPosition;
93
94using WTF::lineEndings;
95
96#endif // TextPosition_h
97